PRIMATTE S-100
for
Autodesk
Manual/Tutorial
Distributed By:
Photron USA, Inc.
9520 Padgett Street, #110
San Diego, CA, USA 92125
Phone: 1-858-684-3555
Web Site: www.photron.com
Primatte office:
Photron USA, Inc.
3113 Woodleigh Lane
Cameron Park, CA 95682
Phone: 1-530-677-9980
FAX: 1-530-677-9981
Cell: 1-530-613-3212
E-mail: sgross@photron.com
Web Site: http://www.primatte.com
Developed By:
PHOTRON Limited
Digix Video Business Unit
3F South Hill, 1-11-30
Nagata-cho, Chiyoda-ku
Tokyo 100-0014, Japan
Phone: +81-3-3595-9101
E-mail: sales@photron.co.jp
Web Site: www.photron-digix.jp
Transferring any part of or the whole of this manual without prior written permission of PHOTRON Limitedinfringes copyright and is prohibited.
(C)2013 PHOTRON Limited. All rights reserved.
As part of our continuing commitment to improvement the content of this manual is subject to change, without prior notice.
This manual is written based on the best knowledge of the author at the time of compilation.
Should you find any errors, please send a note to the author informing of such errors (sgross@photron.com).
1a. LINUX NodeLocked Installation:
1a1. After you have downloaded the spark...
1b. Macintosh NodeLocked Installation:
1b1. After you have downloaded the spark...
1c. Uninstalling NodeLocked Primatte
1c1. Uninstalling NodeLocked Primatte on a Linux or Mac system...
2. Requesting and Installing a sparkPrimatte License Key
2a1. Requesting a NodeLocked sparkPrimatte license for Linux systems
2a2. Installing a NodeLocked sparkPrimatte license on a Macintosh system
2a3. Installing a NodeLocked sparkPrimatte license on a Linux system
2a4. Installing a NodeLocked sparkPrimatte license on a Macintosh system
2b1a. Downloading, Installing and Requesting a Floating License Key
2b1a1. RLM Floating License Manager Installation Steps (LINUX)
2b1a2. RLM Floating License Manager Installation Steps (Windows)
2b1a3. RLM Floating License Manager Installation Steps (Macintosh)
2b1a4. Setting up the floating license
2b1a5. Accessing the floating license on a client system (Linux or Macintosh)
2b1a6. Accessing the floating license on a client system (Windows)
2b1a7. Starting/Stopping the license daemon on a Linux system
2b1a8. Starting/Stopping the license daemon on a Macintosh system
2b1a9. Starting/Stopping the license daemon on a Windows system
2b1a10. Uninstalling the RLM License Server on a Linux system
2b1a11. Uninstalling the RLM License Server on a Macintosh system
2b1a12. Uninstalling the RLM License Server on a Windows system
2b2. Uninstalling Floating Primatte
2b2a. Uninstalling Floating Primatte from a Mac or Linux system...
3. Accessing sparkPrimatte from your Autodesk Application...
4. New Features in Primatte V5
6a. Effect of Spill (+/-) Repeatable Sampling
6b. Effect of Matte (+/-) Repeatable Sampling
6c. Effect of Detail (+/-) Repeatable Sampling
7a. Complemental Spill Replacement
7b. Solid Color Spill Replacement
12. Enhanced Color Correction Features
12a. Ctrl 2 - Foreground Color Correction
12b. Ctrl 3 - Background Color Correction
13. 3D Viewer14. sparkPrimatte Tool and Button Descriptions
14a. Ctrl 1 Page Tools and Buttons
14a2. Operational Mode Selector Tools
14a2m. Make Foreground Transparent
14a3a. Large Polyhedron Slider (Spill Removal)
14a3b. Medium Polyhedron Slider (Transparency)
14a3c. Small Polyhedron Slider (Restore Lost Detail)
14a3d. Fine Tuning Slider Color Chip
14a4. Miscellaneous Ctrl 1 Page Buttons
14a4o. Rectangle/Median/Snail Trail Sample
14a4p. Complement/Solid/Defocus Spill Replacement
14a4p1. Complemental Replacement
14a4p2. Solid Color Replacement
14a4q. Solid Color Spill Replacement Color Chip
14a4r. Linear/Log Image Colorspace
14a4u. Complement/Solid/Defocus Spill Replacement
14a4y2. Grain Tolerance Slider
14b. Ctrl 2 Page Tools and Buttons
14c. Ctrl 3 Page Tools and Buttons
14d. Ctrl 4 Page Tools and Buttons
16. More About the Primatte Polyhedral Slicing Algorithms...
16b. How Primatte RT+ works...
Proprietary Notices:
Primatte is distributed and licensed by Photron USA, Inc., San Diego, CA, USA
Primatte was developed by IMAGICA Digix, Inc., Tokyo, Japan
Primatte is a trademark of IMAGICA Digix, Inc., Tokyo, Japan
1a. LINUX NodeLocked Installation:
1a1. After you have downloaded sparkPrimatte from the Photron web site:
NOTE: If you have downloaded the spark, it will have to be expanded from a compressed state.
1. On the Linux system, open a shell window and log in as root.
2. Copy the downloaded spark into the default spark directory on the Linux system (usually /usr/discreet/sparks).
3. Go to the default spark directory:
% cd /usr/discreet/sparks
4. Extract files from the 'Primatte for Linux' tar archive:
% gunzip Primattev5_WEB_spark_x86.tar.gz
% tar xf Primattev5_WEB_spark_x86.tar
5. 'CD' into the primatte installation directory:
% cd primatte
6. Change the file permissions of the installer.pl file:
% chmod 777 installer.pl
7. Run installer script
% ./install.pl
NOTE: You will be offered the choice of installing either the 32 or 64-bit version. Please choose the correct one for your system.
NOTE: You will be offered the choice of installing NodeLocked or Floating versions. Please choose the correct one based on the license you have requested (or will request).
NOTE: Primatte will appear as sparkPrimatte.spark in the /usr/discreet/sparks/PRIMATTE directory.
NOTE: The manual will be an .htm file in a folder in the /usr/local/PRIMATTE/SPARK/doc folder.
8. At this time you can delete the Primattev5_WEB_spark_x86.tar and the /primatte installation directory
% rm Primatte4.1.1_WEB_spark_x86.tar
% rm -rf primatte
9. Exit root user
10. Proceed to Chapter 2. Getting and Installing a License Key.
1b. Macintosh NodeLocked Installation:
1b1. After you have downloaded sparkPrimatte from the Photron web site:
NOTE: If you have downloaded the spark, it will have to be expanded from a compressed state.
1. Copy the downloaded spark into a known directory.
2. Double-click on the Primatte_v5_SmokeOSXInstaller.mpkg.zip file to unzip it.
3. Double-click on the Primatte_v5_SmokeOSXInstaller.mpkg file to run the install program.
4. Follow the directions on the install program.
5. Close the install program.
6. Proceed to Chapter 2. Getting and Installing a License Key.
1c. Uninstalling NodeLocked Primatte
1c1. Uninstalling NodeLocked Primatte on a Linux or Mac system...
1. Delete all files starting with 'prim' in the /usr/local/etc folder.
% cd /usr/local/etc
% rm -rf prim*.*
2. Delete the /PRIMATTE folder in the /usr/discreet/sparks folder.
% cd /usr/discreet/sparks
% rm -rf PRIMATTE
2. Requesting and Installing a sparkPrimatte License Key
There are two types of licensing available for Primatte for Autodesk M&E, a NodeLocked license and a Floating license. The NodeLock license is locked to single system and the Floating license can be used by any single Autodesk system on the network (unless a multiple floating license is installed). This section of the manual describes how to install and set up the two license systems. This document also describes how to request a license key password file and instructions on how to activate the sparkPrimatte software once you have the license key.
NOTE: This version of Primatte no longer uses the FlexLM floating license technology. This version uses Reprise Floating License technology (RLM). See below for installation instructions as to how to download and install the floating license versions.
2a1. Requesting a NodeLocked sparkPrimatte license for Linux systems:
1. To request a license key from Photron, you have to determine the system's Primatte serial code.
2. Go to the /usr/discreet/sparks/PRIMATTE/ directory (if you are not already there):
% cd /usr/discreet/sparks/PRIMATTE
3. Execute the ./GetSerialCode program:
% ./GetSerialCode
4. Send this information to Scott Gross by e-mail (sgross@photron.com) or FAX (1-530-677-9981) and he will send you a temporary license key for your system. You can also log onto the Primatte web site (http://www.primatte.com) and request a license in that manner.
2a2. Requesting a NodeLocked sparkPrimatte license for Macintosh systems:
1. To request a license key from Photron, you have to determine the system's MacAddress.
2. 'cd' to the /usr/discreet/sparks/PRIMATTE/ directory (if you are not already there):
% cd /usr/discreet/sparks/PRIMATTE
3. Execute the ./PrimatteGetMac program:
% ./PrimatteGetMac
4. Send this information to Scott Gross by e-mail (sgross@photron.com) or FAX (1-530-677-9981) and he will send you a temporary license key for your system. You can also log onto the Primatte web site (http://www.primatte.com) and request a license in that manner.
2a3. Installing a NodeLocked sparkPrimatte license on a Linux system:
NOTE: The sparkPrimatte license key file is provided to you from Photron and may have been FAXed to you or e-mailed.
1. The NodeLock license will consist of a string of twenty lowercase alpha characters.
Example: nijpgheeeediclaaxcre
2. Use jot or vi to create a file named prim4.txt in the /usr/local/etc directory.
NOTE: The /usr and /local directories should already be there, but you may have to create the /etc directory using the mkdir command.
3. Open permissions on the file.
4. Copy the single line of text that makes up the license key into this text file. You may choose to end the file with a carriage return or not.
NOTE: Do not copy the lines above or below the license key characters. Just the twenty alpha characters.
2a4. Installing a NodeLocked sparkPrimatte license on a Macintosh system:
NOTE: The sparkPrimatte license key file is provided to you from Photron and may have been FAXed to you or e-mailed.
1. The NodeLock license will consist of a string of twenty lowercase alpha characters.
Example: nijpgheeeediclaaxcre
2. After the installation of the sparkPrimatte application, a window will open on the desktop labeled as prim5.txt.
3. Paste the license you received in the window where it says "enter license here".
NOTE: Do not copy the lines above or below the license key characters. Just the twenty alpha characters.
4. Save the prim5.txt file and close the window.
NOTE: If you see "Security Error (1) ID 1" when you try to access sparkPrimatte, please try following in a Terminal window.
% su
% passwd: (enter the super user password)
% chmod 666 /usr/local/etc
% chmod 777 /usr/local/etc/prim5txt
% exit
NOTE: The floating license server can be on a Linux, Windows or a Macintosh system. It will assign licenses to both Mac and Linux systems.
2b1. Installing the RLM Floating License Manager and Requesting a Floating sparkPrimatte license for a LINUX, Windows or a Macintosh system:
NOTE: To request a license key from Photron, it helps to have first installed the IMAGICA RLM License Manager software on a LINUX, Windows or Macintosh system along with the spark. The IMAGICA RLM License Manager is a license management system (based on Reprise License Manager) that allows you to execute IMAGICA/Photron products with a floating license.
NOTE: Superuser privileges are necessary to execute the following steps.
2b1a. Downloading, Installing and Requesting a Floating License Key
NOTE:Download the RLM floating license manager to a known location on your system. You can download these packages from http://www/primatte.com:
- LINUX: The download file is labeled as RLM Floating License Manager (64-bit Linux version) and the file is named imagica_rlm_server.tar.bz2.
- Windows: The download file is labeled as RLM Floating License Manager (Windows version) and the file is named imagica_rlm_server_setup.exe.
- Macintosh: The download file is labeled as RLM Floating License Manager (Macintosh OSX version) and the file is named imagica_rlm_server.pkg.
2b1a1. RLM Floating License Manager Installation Steps (LINUX):
1. Unzip and untar the file
% bunzip2 imagica_rlm_server.tar.bz2 (64-bit Linux version)
% tar –xvf imagica_rlm_server.tar (64-bit Linux version)
2. Drop down into the server directory:
% cd imagica_rlm_server
3. Login as root (if you are not already)
4. Change permissions on the installer script by typing:
% chmod 777 imagica_rlm_server_install.sh
5. Run the installer script by typing:
% sh ./imagica_rlm_server_install.sh
NOTE: This command creates the /usr/imagica and /var/rlm/imagica directories.
6. Go to the RLM bin directory:
% cd /usr/imagica/bin
7. Get the system's "rlmhostid":
% ./rlmhostid
NOTE: The "rlmhostid" will be a twelve digit hexadecimal number.
8. Get the system's "hostname":
% hostname
NOTE: The "hostname" will be a text string.
9. Exit root user
10. For a Primatte license send the "hostname" and the "rlmhostid" to sgross@photron.com and they will return a license key.
2b1a2. RLM Floating License Manager Installation Steps (Windows):
1. Double-click on the imagica_rlm_server_setup.exe file.
2. Select a language.
3. Select Next.
4. Select Install.
5. Click Finish to close the installer.
6. Open a shell window and go to the RLM bin directory ({INSTALL_DIRECTORY}/bin):
% cd C:/Program Files (x86)/DIGIX/FloatingLicenseManager/bin
7. Get the system's "rlmhostid":
% rlmhostid
NOTE: The "rlmhostid" will be a twelve digit hexadecimal number.
NOTE: If more than one rlmhostid is displayed, please note all of them and send them along with your floating license request.
8. Get the system's "hostname":
% hostname
NOTE: The "hostname" will be a text string.
9. Close the shell window.
10. For a Primatte license send the "hostname" and the "rlmhostid" to sgross@photron.com and they will return a license key.
2b1a3. RLM Floating License Manager Installation Steps (Macintosh):
1. Copy the downloaded license manager into a known directory.
2. Double-click on the imagica_rlm_server.mpkg.zip file to unzip it.
3. Double-click on the imagica_rlm_serverr.mpkg file to run the install program.
4. Follow the directions on the install program.
5. Close the install program.
NOTE: This command creates the "/usr/local/DIGIX" directory.
6. Go to the RLM bin directory:
% cd /usr/local/DIGIX/FloatingLicenseManager/bin
7. Get the system's "rlmhostid":
% ./rlmutil rlmhostid internet
NOTE: The "rlmhostid" will be a twelve digit hexadecimal number.
8. Get the system's "hostname":
% hostname
NOTE: The "hostname" will be a text string.
9. Exit root user
10. to get a Primatte license send the "hostname" and the "rlmhostid" to sgross@photron.com and they will return a license key.
2b1a4. Setting up the floating license
NOTE: Your license file is distributed by e-mail.
NOTE: A temporary license for Primatte will look something like this:
-----------------------------------------------------------------------------------------------
# Generated on 2010-11-18 13:20:24
# HostID(macaddress) [ 11:22:33:44:55:66 ]
# (expires on 30-nov-2010)HOST imagica 112233445566 5053
ISV photron
LICENSE photron sparkprimatte 4.00 30-nov-2010 1 share=uh
_ck=26d6ff8238 sig="60Q04580GC96TVWEA2TYTV8FC924NYM83YYJACUJ08AG1H2F
7PY058C4HNCXF3YTA1K30KG48U3Y8"----------------------------------------------------------------------------------------------
NOTE: A permanent license for Primatte will look something like this:
-----------------------------------------------------------------------------------------------
# Generated on 2010-11-18 13:20:46
# HostID(macaddress) [ 11:22:33:44:55:66 ]
# (permanent license)HOST imagica 112233445566 5053
ISV photron
LICENSE photron sparkprimatte 4.00 permanent 1 share=uh _ck=1dd6ffedc4
sig="60P04513XFKA3T4ANDVN5964KSW0U11S2R6AN4R22GG9VX4HD3YD1BBQ2B1EDGW
F3CP7UBSYUR"----------------------------------------------------------------------------------------------
1a. For Linux and Macintosh, save the license text in a file named 'license.dat' in the "/var/rlm/imagica/ " directory.
1b. For Linux and Macintosh, open permissions on the license file:
% chmod 777 /var/rlm/imagica/license.dat
1c. For Windows, save the license text in a file named 'license.dat' in the "C:/Program Files (x86)/DIGIX/FloatingLicenseManager/lic" directory.
NOTE: If you have already had an RLM license file in that directory, append the Primatte license text string to the existing file (the line that starts with the word “LICENSE”. If the existing license file includes the same HOST line and the same ISV line, you can omit these lines.
NOTE: In the license file, any lines that start with the '#' character are comments and are ignored by the software that reads the license.
2b1a5. Accessing the floating license on a client system (Linux or Macintosh) if the server is on another system.
1. Create a /var/rlm/imagica directory.
2. Create a file named license.dat.
3. Put this line in the license.dat file:
HOST (servername) (server ipaddress)
Example: HOST MacPro.local 192.168.0.9
...or...
HOST (server ipaddress)
NOTE: To use this format, the /etc/hosts file must have the (servername) and (server ipaddress) in it.
Example: 192.168.0.79 flare
2b1a6. Accessing the floating license on a client system (Windows) if the server is on another system.
1. Create a C:\Program Files (x86)\DIGIX\FloatingLicenseManager\lic\ directory.
2. Create a file named license.dat.
3. Put this line in the license.dat file:
HOST (servername) (server ipaddress)
Example: HOST MacPro.local 192.168.0.9
...or...
HOST (server ipaddress)
2b1a7. Starting/Stopping the license daemon on a Linux system:
- To start the service:
% cd /usr/imagica/etc
% sh /usr/imagica/etc/imagica_rlm_start
- To stop the service, you can use a standard Linux method for stopping a service or type:
% sh /usr/imagica/etc/imagica_rlm_stop
NOTE: The service will be automatically started upon reboot.
NOTE: If the daemon does not start for Primatte, open the /var/tmp/imagica.log file and send it to sgross@photron.com.
2b1a8. Starting/Stopping the license daemon on a Macintosh system:
- To start the service:
% cd /usr/local/DIGIX/FloatingLicenseManager
% sh imagica_floating_license_manager_start.sh
- To stop the service, you can use a standard Linux method for stopping a service or type:
% cd /usr/local/DIGIX/FloatingLicenseManager
% sh /imagica_floating_license_manager_stop.sh
NOTE: The service will be automatically started upon reboot.
NOTE: If the daemon does not start for Primatte, open the /usr/local/DIGIX/FloatingLicenseManager/imagica_rlm_log txtfile and send it to sgross@photron.com.
2b1a9. Starting up the license daemon on a Windows system:
- To start or configure the service:
- Open a browser and access this URL...
http://localhost:5054/
- Click on the Reread/Restart Servers button.
- To stop the service, you can use a standard Linux method for stopping a service or type:
- Open a browser and access this URL...
http://localhost:5054/
- Click on the Shutdown button.
NOTE: The service will be automatically started upon reboot.
NOTE: If the daemon does not start for Primatte, open the C:/Program Files (x86)/DIGIX/FloatingLicenseManager/logs/license.log file and send it to sgross@photron.com.
2b1a10. Uninstalling the RLM License Server on a Linux system:
- To uninstall the Imagica RLM system, open a shell window (and as Superuser) type:
% /usr/imagica/etc/imagica_rlm_stop
NOTE: This command erases the chkconfig entry and removes the related files in /etc/rc[02].d.
- After executing the above command, remove the imagica_rlm_server package.
% rm -rf /usr/imagica
% rm -rf /var/rlm/imagica
2b1a11. Uninstalling the RLM License Server on a Mac system:
- To uninstall the Imagica RLM system, open a shell window (and as Superuser) type:
% cd /usr/local/DIGIX/FloatingLicenseManager
% sh imagica_floating_license_manager_stop.sh
NOTE: This command erases the chkconfig entry and removes the related files in /etc/rc[02].d.
- After executing the above command, remove the imagica_rlm_server package.
% rm -rf /usr/local/DIGIX/FloatingLicenseManager
% rm -rf /var/rlm/imagica
2b1a12. Uninstalling the RLM License Server on a Windows system:
- Double-click on the C:/Program Files (x86)/DIGIX/FloatingLicenseManager/Uninstall.exe program.
- After it has completed, delete the C:/Program Files (x86)/DIGIX directory.
2b2. Uninstalling Floating Primatte
2b2a. Uninstalling Floating Primatte from a Mac or Linux system...
1. Go to the /var/rlm folder.
% cd /var/rlm
% rm -rf /imagica
2. Delete the /PRIMATTE folder in the /usr/discreet/sparks folder.
% cd /usr/discreet/sparks
% rm -rf PRIMATTE
3. Accessing the Primatte spark from your Autodesk application
1. Start up flame/flint/fire/inferno/smoke and click on the EFFECTS button.
2. If you don't see the sparkPrimatte button in the EFFECTS menu, hold down the ALT key and click on the sparks button. This will bring up an Autodesk 'file browser' window. Click on the sparkPrimatte.spark name (it should be located in the /usr/discreet/sparks/PRIMATTE directory) and sparkPrimatte will be registered as a spark button in the EFFECTS window.
3. Click the sparkPrimatte button within the panel, and the cursor will turn to a red color. 
4. Use this red cursor to select a foreground clip. Put the point of the cursor to the numbers in the upper-left corner of the clip to select it.
5. The cursor will then turn to a green color. 
6. Use this green cursor to select a background clip in the same manner as the foreground clip.
7. The cursor will then turn to a blue color. 
8. Use this blue cursor to select a garbage matte clip in the same manner as the foreground clip. If you are not using a garbage matte, just click again on the background clip.
9. After this step, the cursor will turn to a white color 
. Select a place to put the destination reel.
10. At this point, the user should be presented with the Primatte control panel:
Note: sparkPrimatte can also be started up by using Autodesk M&E's Same Clips Shortcut.
Note: If the user gets an "Inadequate Cryptogram Error" message, then sparkPrimatte is unable to find the Primatte license file (prim4.txt) in the /usr/local/etc directory. Follow these procedures to solve the problem:
Step #1: Make sure that the license key string is in a file named prim4.txt and is located in the /usr/local/etc directory. Make sure that permissions are open on it (chmod 777 prim4.txt). Ensure that the file contains only the one line of text that was sent to you (it can end with a CR or not). Do not include the '--start key---' or '---end key---' lines.
Step #2: Make sure that there are no other files named prim4.txt on the system. sparkPrimatte first looks for a $HOME/prim4.txt file before it looks for /usr/local/etc/prim4.txt. If it finds an older expired license string it kicks out with the "inadequate cryptogram" error message and never finds the valid license.
Step #3: Make sure that you have the right spark version. Make sure it is in the /usr/discreet/sparks/PRIMATTE directory and has a .spark extension (for example: sparkPrimatte.spark or Primatte.spark). Make sure that permissions are open on it also.
Step #4: Make sure that the Primatte Serial Code that you sent to Photron is correct for the system that you are using. See Section 2a1. above.
Note: If the user gets an "RLM license error" message, then sparkPrimatte is unable to find Primatte's RLM floating license. See Section 2b. above.
4. New Features in Primatte V5
NOTE: This section gives an overview of the three new features in Primatte V5. Additonal details on the tools are included in the manual further down in this document.
Adjust Lighting was developed to solve the problem of compositing artists getting backing screens that have very uneven lighting. In this first example you can see the backing screen is very light on one side and dark on the other.
If we sample a shade of blue in the upper right hand corner of the image to select the backing screen color, our matte view shows that it is very clean on the right side of the person and noisy on the other side.
When we look at a close-up --- We can see that the hair near the sampled color has a good key but on the other side the hair is chunky and the key is not very good.
To solve this problem, we first create a grid on the foreground image. We then sample the grid to determine which squares contain foreground information and which contain some shade of the background color using the remaining shades of blue, we use extrapolations of the existing backing screen colors and then use this technique to fill in the area previously covered by the foreground object. This results in a clean backing screen that has no foreground object. Primatte uses this clean backing screen as the reference data to process the original foreground image to generate light-adjusted foreground that has a much more even shaded of blue with the foreground object. Primatte now performs the chromakeying operation using this light-adjusted foreground. And, as you can see, it results in a clean key around all areas on the foreground object.
If we look at close-ups of the hair, we see that we now have a clean key on both sides of the foreground object.
Unevenly lit backing screens has been described as one of the biggest problems for compositing artists and Primatte's adjust lighting technique has been developed to help alleviate this situation. Here are three more examples...
The previous version of Primatte had a new feature called "Auto-Compute' that was supposed to detect the backing screen color, eliminate it and result in a clean matte with the foreground detected accurately with a single click on a backing screen pixel. Unfortunately, it failed to do this on many images with small backing screen areas and other unusual conditions. The first step in fixing this problem was to solve the 'incomplete backing screen detection of the auto-compute feature. Here are some samples of images we had problems with previously.
These all had small areas of backing screen and so Primatte failed to detect the backing screen. So the problem here was a small backing screen area and a large foreground object. In version 5 of Primatte, we took the RGB color information and applied it to the equivalent colorspace on a vectorscope.
We then created a histogram of the information and analyzed it. For this image, you can see the resulting histogram of this calculation.
The next step is detecting the summits of the mountains that are to be the candidates of the backing color.
As you can see, the hair color had the highest summit, the flesh tomes came in second and the backing screen has the smallest summit.
We then weighted the result and using several factors in the algorithm used in version , we can see that the hair color got the highest rating, the skin color came in second place, and the backing screen color came in last place.
We then introduced two additional factors; one is the inverse of the variance of the color distribution, the other is the color saturation to rate the candidates. We now get a result where the backing screen color gets the highest rating and we accurately detect the proper backing screen color.
Here are the results using the new algorithm on the images we viewed previously. As you can see, in each case we accurately detected the proper backing screen color.
The second problem with the Primatte Version 4 "Auto-Compute" feature was 'incomplete foreground estimation'. In these cases, some areas of the foreground object were not detected as complete foreground and the result was that some or the entire foreground object ended up as semi-transparent or completely transparent.
The problems here were the common chromakey problems of 'pink and cyan against a blue backing screen' and 'flesh tones against green backing screens'. To solve these problems, we must first look at the basic Primatte algorithm. After selecting a backing screen color, Primatte V would project a line from the backing screen color to the opposite colorspace and using a predefined angle, the polyhedrons that defined the foreground colors would be created.
The problem occurs when we look at where the pink color ends up residing.
If we look at a green screen example we can see what happens when the Primatte V algorithm is applied in the same manner. The flesh tones end up in the transparent area.
If we take the colorspread of a foreground image in RGB -D colorspace, flatten it out using Primatte's patented "blue-screen coordinate system" and scan it to create a histogram, we can easily diffentiate what the foreground and background colors are. Here is an example of a bluescreen image. As you can see, it would have worked fine in the older version of Primatte becasue it was easy to create a histogram and determine which were the foreground and which was the backing screen color.
Unfortunately, if we do the same with this greenscreen image, we see that the resultant histogram is worthless in defining the foreground and background colors.
However using a new technique call 'principle component analysis', Primatte V is able to create a histogram from the same image that clearly defines the foreground and background color components on this image. A line is first projected through the flattened color information.
Then the information is shifted prior to creating the histogram.
Now we get a useful histogram that allows differentiationbetween the foreground and backing screen.
We now get the correct results on the problem images viewed earlier.
Before:
After:
The new histogram analysis achieves better backing detection and automatic foreground extraction.
The 'Hybrid Mode' simplifies a technique often used by compositing artists when faced with the problem of a color on the foreground object that is close to the backing screen color. If a foreground person's shirt has purple stripes and they have been shot against a blue backing screen, when the backing screen color is selected to be keyed out, the purple stripes become transparent. If Primatte's "Clean Foreground Noise" tool is then used to make the shirt a solid color, a purple fringe appears along the edge of the person's face that is hard to remove and makes for a bad edge. This is because the color in the purple stripes may also exist in the linear transition pixels that blend the foreground object's face and the backing screen.
This is an inherent problem of blue and green screen matting. The 'Hybrid Mode' internally creates two keys internally from the same image. One has a clean edge on the foreground but with transparency where the stripes are and the other one has the transparency removed but suffers from the bad edges on the foreground object. The one with the bad edges then has a 'shrink matte' operation applied to it and it is composited over the one with the key that has the transparency, resulting in a composite with the best of both options. Previously this had to be down as two separate operations.
The hybrid mode is useful when a greenish area on the foreground has been shot against a green screen and when a bluish foreground object is shot against a blue backing screen. In either case, the 'hybrid mode' delivers a nice smooth edge and a clean composite.
Return to Contents link
NOTE: This section describes the basic operation of the Primatte plug-in. A more detailed explanation of how the Primatte algorithm actually works can be found in Section 13 of this manual.
- Click on the Auto-Compute button.
NOTE: This version of Primatte has a new, improved version of a tool that should eliminate the first three steps of using Primatte. It is called the Auto-Compute button
and may make your keying operation much easier. You can click on this button as a first step and it may automatically sense the backing screen color, eliminate it and even get rid of some of the foreground and background noise that would normally be cleaned up in Steps 2 (Clean BG Noise) and 3 (Clean FG Noise) of the Primatte operation. If you get good results then click here to jump ahead to the spill removal tools.
NOTE: If you don't get the results you wanted from Auto-Compute, please continue from this point on to learn the basic Primatte operation procedures...
NOTE:The basic functionality for the sparkPrimatte interface is centered around these four buttons and the image window. The top field (indicated here by the Smart Select BG Color button) is the Operational Selector where you select which operational mode you want to use.
- There are four main steps to using the sparkPrimatte and Smart Select BG Color is the first step and comes up as the default when the spark is first opened. The other options available from this button are shown below. This is called the Operational Mode Selector.
Note: The operation of sparkPrimatte can be executed by using either the pressure-sensitive pen or a mouse. Press down the pressure-sensitive pen and drag it around within the image or make a single pixel selection to sample the color. Release the pressure-sensitive pen slowly, and sparkPrimatte will start the keying computation. Do not release the pen too quickly or sparkPrimatte may fail to detect the weaker pressures. The right mouse button applies the equivalent of strong pen pressure and the left mouse button applies the equivalent of a weak pen pressure. Press the right button and drag the mouse to sample a color, release the button to display the sampled color and start the computation.
- Click on the Result
button on the left hand side of the Monitor Selector. This will change the image in the monitor window to the Composite View.
- Ensure that the Operation Mode Selector in the pop-up menu is set to Smart Select BG Color
.
- Position the cursor in the bluescreen area (or whatever background color you are using), near the foreground object. Sample the targeted background color. Release the pressure-sensitive pen slowly, and sparkPrimatte will start the compositing process. If the foreground shot was done under ideal shooting conditions, sparkPrimatte will have done 90-95% of the composite in this one step.
NOTE: The Smart Select BG Color operational modeis optimized for blue or green backing screens. Primatte will work equally well with any color backing screen. It does not have to be a specific shade of green or blue. If you are using a different color, please use the Simple Select BG Color
operational mode to start the operation.
TIP: If you dragged the cursor in the blue area, sparkPrimatte averages the multi-pixel sample to get a single color to adjust to. Sometimes sparkPrimatte works best when only a single pixel is sampled instead of a range of pixels. The color selected at this point in the Primatte operation is critical to the operation of the spark from this point forward. Should you have difficulties further along in the tutorial after selecting a range of blue shades, try the Select BG Color operation again with a single dark blue pixel or single light blue pixel.
TIP: If the foreground image has a shadow in it that you want to keep in the composite, do not select any of the dark blue pixels in the shadow and the shadow will come along with the rest of the foreground image.
- The second and third steps should not be necessary when using the Smart Select BG Color operational mode but is included here in case the Smart Select BG Color operation did not give the desired results. To do the following steps in sparkPrimatte, it requires viewing the Matte View in the monitor window. Click on the Matte Output
button located on the top of the right-hand side column. The image displayed in the monitor window will change to a black and white `matte' view of the image.
- Change the Operational Mode Selector from Smart Select BG Color to Clean BG Noise
. If there are any white regions in the dark, `bluescreen area', it is 'noise' (or shades of blue that did not get picked up on the first sample) and should be removed. Move the cursor through these areas if using the Snail Trail sampling method (or make a box around them if using the Rectangular Sampling method) and sample these whitish noise regions. When you let up on the pen or mouse button, sparkPrimatte will process the data and eliminate the noise. Repeat this procedure as often as necessary to clear the noise from the background areas. Sometimes increasing the brightness of your monitor or the screen gamma allows you to see noise that would otherwise be invisible.
Before Background noise removal After Background noise removal
NOTE: You do not need to remove every single white pixel to get good results. Most pixels displayed as a dark color close to black in a key image will become transparent and virtually allow the background to be the final output in that area. Consequently, there is no need to eliminate all noise in the bluescreen portions of the image. In particular, if an attempt is made to meticulously remove noise around the foreground object, a smooth composite image is often difficult to generate.
TIP: When clearing noise from around loose, flying hair or any background/foreground transitional area, be careful not to select any of areas near the edge of the hair. Leave a little noise around the hair as this can be cleaned up later using the Fine Tuning (Sliders) tool.
- If there are dark regions in the middle of the mostly white foreground object, that is, if the key is not 100% in some portion of the targeted foreground, choose Clean FG Noise
from the Operational Mode Selector pop-up menus. Use the same techniques as for Clean BG Noise, but this time sample the dark pixels in the foreground area until that area is as white as possible.
Before Foreground Noise Removal After Foreground Noise Removal
- These were the steps necessary to create a clean 'matte' or 'key' view of the image. With this key, the foreground can be composited onto any background image. However, if there is `spill' on the foreground object from light that was reflected off the background, a final operation is necessary to remove that background spill get a more natural looking composite.
- For the fourth step in the sparkPrimatte operation, return the Composite view to the monitor window by clicking again on the Matte Output
- The sample image below has gone through the first three steps and has examples of spill. Notice the blue fringe to her hair and a blue tint on her right cheek, arm and chest.
Spill Removal - Method #1
- There are three ways in Primatte to remove the spill color. The quickest method is to select the Spill Sponge
button from the Operational Mode Selector and then sample the spill areas away. By just positioning the cursor over a bluish pixel and selecting it, the blue will disappear from the selected color region and be replaced by a more natural color. Additional spill removal should be done using the Fine Tuning (Sliders) feature or the Spill (-) feature. Both are explained further on in this manual.
Note: All spill removal/replacement operations in Primatte can be modified using the Background Spill Replacement tools. Spill can be replaced with either the complement of the background color, a solid color selected by the user or by colors brought from a defocused copy of the background. Depending on the spill conditions, one of these options should provide the results you are looking for. See the information in 7. Spill Replacement Options for more details.
Note: Primatte's spill removal tools work on 'color regions'. In the image above, samples should be made on the light flesh tones, the dark flesh tones, the light blonde hair, the dark blonde hair and the red blouse color regions. One sample in each color region will remove spill from all similar colors in the foreground image.
- If the spilled color was not been totally removed using the above procedure, a fine-tuning operation Spill (-) tool should follow for more subtle and sophisticated removal of the spilled background color.
Spill Removal - Method #2
- Select the Fine Tuning (Sliders)
button under the Operational Mode Selector.
- Using the zoom and pan capabilities of the Autodesk M&E application, zoom into an area that has some blue edges.
- Using the cursor, sample a range of the blue pixels that you want to remove. When you let up on the pen or mouse button, sparkPrimatte will register the color selected in the Color Chip
just below the Sm. Poly (Detail)
slider. For most images, the Large Poly (Spill)
slider is all that is required to remove any remaining bluespill. The more to the right the slider moves, the more background screen color will be removed from the sampled pixels. The more to the left the slider moves, the more the selected pixels will move toward the original foreground image's color. The sliding operation is performed by clicking on the Large Poly (Spill) button and sliding the pen or mouse left or right to change the value.
Note: When using the slider in the Fine Tuning (Sliders) mode to remove spill, spill color replacement will be replaced based on the setting of the Spill Replacement Buttons. See Spill Replacement Buttons for more information in Chapter 12. sparkPrimatte Tools and Buttons.
Note: In the Fine Tuning (Sliders) mode, re-computation of the composite image will not be accomplished if the pressure-sensitive pen is released too slowly.
TIP: It is better to make several small adjustments to the bluespill areas than a single major one.
- You can use the other two sliders in the same way for different key adjustments. The Sm. Poly (Detail)
slider controls the matte softness for the color which is closest to the foreground color. For example, if you have thick and opaque smoke in the foreground, you can make it semi-transparent by moving the Med. Poly (Trans.) slider to the right after selecting the pixels in the Fine Tuning (Sliders) mode.
TIP: If the foreground image changed color dramatically during the fine tuning process, you can recover the original color by selecting an area of the off-color foreground image and moving the Large Poly (Spill) slider slightly to the left. This may introduce bluespill back into that color region. Again, use the Fine Tuning (Sliders) option to suppress the blue, but make smaller adjustments this time.
Spill Removal - Method #3
- This method uses a new Primatte tool that is covered in the next section Chapter 6. Repeatable Sampling Tools.
NOTE: If these final 'spill suppression' operations have changed the final compositing results, you may have to return to earlier operations to clean up the matte. If the Composite view looks good, it is a good idea to go back and take a final look at the Matte View. Sometimes in the Primatte operation, a 100% foreground area will become slightly transparent. You can clean those transparent areas up by using the Matte Sponge
button. After selecting the Matte Sponge operational mode, just click on the transparent pixels and they will become 100% foreground. All of the spill-suppression information will remain intact. Alternatively, you can go to the Matte view and then using the Fine Tuning (Sliders) option, select those transparent areas and move the Med. Poly (Trans.) slider slightly to the left. This will move that color region from 0-99% foreground with spill suppression to 100% foreground with spill suppression and should solve the problem. The Matte (+) tool will also work to solve this problem.
Most of the Primatte operations are done using a 'mouse sampling' operation. The only exceptions are the Fine Tuning (Sliders) operational mode and its sliders. The Fine Tuning operation gives a continuous valuator for fine-tuning but some of the sliders are not often used because results are often unpredictable.
Note: Another weak point in previous versions of sparkPrimatte is the lack of functionality to attenuate and thicken the existing matte density. This version of sparkPrimatte offers a more intuitive, easy-to-use and powerful user interface called the Repeatable Sampling Operation.
In addition to the conventional sparkPrimatte operation modes, six new modes are added:
/ Spill (+)
\ Spill (-)
/ Matte (+)
\ Matte (-)
/ Detail(+)
\ Detail(-)
- Using the Spill (+) and Spill (-) modes, you can gradually remove or recover the spill intensity on the foreground object by sampling the referenced color region repeatedly. The conventional Spill Sponge tool removes the spill component in a single action at one level and did not allow sampling the same pixel a second time. Even though just a small amount of spill needed to be removed, the spill sponge removed a preset amount without allowing any finer adjustment.
Effect of Spill (+/-) Repeatable Sampling
- Using the zoom and pan capabilities of the Autodesk M&E application, zoom into an area that has some blue edges and click on a pixel with some spill on it. Repeated clicking will incrementally remove the spill. Continue this operation until the desired result is achieved.
- The Matte (+) and Matte (-) modes are used to thicken or attenuate the matte information. If you want a thinner shadow on a foreground object, you can use the Matte (-) mode as many times as you like to make it more transparent. On the other hand, you can use the Matte (+) mode to make the matte thicker in that color region.
Effect of Matte (+/-) Repeatable Sampling
- The Detail (+) and Detail (-) modes are a refined version of Clean BG Noise and Restore Detail. For example, when you see some dilute noise in the backing area but don't want to remove it completely because it affects some fine detail in a different area, try using Detail (-). It will attenuate the noise gradually as multiple samples are made on the pixel. You should stop the sampling when important fine details start to disappear.
Effect of Detail (+/-) Repeatable Sampling
The proper processing of spill on foreground objects is one of the many useful features of Primatte. There are now three spill processing methods whereas older versions of the sparkPrimatte product supported only one or two of them. The three methods are as follows:
- Complemental Spill Replacement
- Solid Color Spill Replacement
- Defocus Spill Replacement
7a. Complemental Replacement Mode:
- This is the default spill replacement mode. This mode will maintain fine foreground detail and deliver the best quality results. If foreground spill is not a major problem, this mode is the one that should be used.
- The Complemental Replacement mode is sensitive to foreground spill. If the spill intensity on the foreground image is rather significant, this mode may often introduce serious noise in the resultant composite.
7b. Solid Color Replacement Mode:
- In the Solid Color Replacement mode, the spill component will be replaced by a 'user defined' palette color. While the Complemental Replacement mode uses only the backing color complement to remove small amounts of spill in the original foreground, the Solid Color Replacement mode tries to assuage the noise using the 'user defined' palette color. Changing the palette color for the solid replacement, the user can apply good spill replacement that matches the composite background. Its strength is that it works fine with even serious blue spill conditions.
- On the negative side, when using the Solid Color Replacement mode, fine detail on the foreground edge tends to be lost. The single palette color sometimes cannot make a good color tone if the background image has some high contrast color areas.
- The Defocus Replacement mode uses a defocused copy of the background image to determine the spill replacement colors instead of a solid palette color or just the complement color. This mode can result in good color tone on the foreground object even with a high contrast background. As in the example below, spill can even be removed from frosted glass using this feature and still retain the translucency.
- On the negative side, the Defocus Replacement mode sometimes results in the fine edge detail of the foreground objects getting lost. Another problem could occur if the user wanted to later change the size of the foreground image against the background. Since the background/foreground alignment would change, the applied color tone from the defocused image might not match the new alignment.
A new method of defocusing the matte has been added. This new feature only blurs inward toward the center of the foreground subject. The conventional Primatte defocus feature affected the matte edges in both directions (inward and outward) and sometimes introduced a halo artifact around the object edge in the composite view. This was most evident when using the Complemental Replacement mode. With the Inward Defocus switch ON, the matte defocus functions only in the inward direction of the foreground subject (toward the center of the white area). The final result is that it removes small and dark noise in the backing area without picking them up again in the Clean BG Noise mode and sometimes results in softer, cleaner edges on the foreground objects.
sparkPrimatte now accepts a hand-drawn matte as the external matte to hide the unnecessary garbage like light arms, microphones and other undesirable foreground object. Areas that are white in the garbage matte clip will take the pixels from the background and areas that are black will be from the composite image. This External Matte can also be inverted.
If you have a noisy image as in the example below...
...you will find that the matte is also noisy:
Currently you can use the Clean BG Noise operation mode to remove the noisy pixels, but this can also modify the edge of the foreground object in a negative manner.
Using the Grain Tools in the following way may help you clean up the image and still get a good edge on the matte:
1. Use the Clean BG Noise operation modejust a small mount to remove some of the white noise in the Matte View but do use it so much that you affect to the edge of the foreground object.
2. Then select the Grain Size tool
and select Small
as a first step to reduce the grain:
With the Grain Tol.
slider set at 0, move it around some. This should increase the affect of the Clean BG Noise tool without changing the edge of the foreground object.
Sometimes this may not be enough to totally remove the grain so by adjusting the Grain Tol. slider, you can tell the Primatte algorithm what brightness of pixels you think is grain. You should try not to use too high of a value otherwise it will affect the overall matte. For an example of an 'over adjusted' image see below...
The Primatte grain algorithm uses a 'Defocused Foreground' image to compute the noise. You can see the results of the defocused foreground by changing the View Mode to Defocus FG
:
NOTE: The Small, Medium and Large settings for the Grain Tool all produce defocused foregrounds that have larger blurs respectively.
NOTE: It is important to make sure that the crop settings are correctly applied otherwise when the defocus image is generated, if there is 'garbage' on the edges of the images, then that garbage will be blurred into the defocus foreground.
As a review:
1. Select the Select BG Color operation modeand click on a backing screen color.
2. Select the Clean BG Noise operation mode and use it sparingly so that it has minimum affect to the edge of the foreground object.
3. If there is still grain in the backing screen area, then use the Grain Size functionality starting at the Small setting to reduce the grain
4. If the grain is still present, then try increasing the Grain Tol. slider a little - not too much.
5. If grain is still a problem then try changing the Grain Size to Medium of Large and also changing the grain tolerance until the desired effect is achieved.
NOTE: The grain functionality does not always remove grain perfectly but is sometimes useful to minimize its effects.
- flame/flint/fire/inferno/smoke can import Cineon 10-bit log image files but be aware that in doing so, it converts the image color space into a '12-bit linear' or '8-bit linear' format. This may cause some color quantum errors even though they work in the 12-bit color mode. On the other hand, Primatte internal calculations are calculated using '16-bit linear'. This is enough precision to accurately represent 10-bit log information. However, if it was once converted to '12-bit linear' by flame/flint/fire/inferno/smoke, Primatte cannot maintain or recover the lost data.
- sparkPrimatte Version 3.0 now supports '12-bit log' and '8-bit log' data for the IFFFE3's image buffer. Users can just import the Cineon 10-bit with a simple custom LUT that just shifts up two bits or shifts down two bits from the original 10-bit data. Primatte converts the 12-bit/8-bit log data directly to the high precision, internal 16-bit linear space, processes it and re-converts back to 12-bit/8-bit log space.
- The reference white, reference black and the soft clip levels of the log-linear conversion table can also be controlled by the user for high quality color manipulations by setting the following environmental variables:
[Reference White] PRIMLOG_REFWHITE (default=685)
[Reference Black] PRIMLOG_REFBLACK (default=95)
[Soft Clip] PRIMLOG_SOFTCLIP (default=0)
The shell command line can be used to preset the data:
Example: %setenv PRIMLOG_REFWHITE 690
- A conversion graph with soft clipping for a log space image is shown below.
12. Enhanced Color Correction Features
12a. Ctrl 2 - Foreground Color Correction
Foreground color correction tools have been enhanced in this version of Primatte. New features include a gang slider for the Gain, Setup and Gamma controls of the RGB channels and partial reset buttons for Gain, Setup and Gamma controls. See 11. sparkPrimatte Tools and Buttons for more information about using these new features.
12b. Ctrl 3 - Background Color Correction
Background color correction tools have also been enhanced in this version of Primatte. New features include a gang slider for the Gain, Setup and Gamma controls of the RGB channels and partial reset buttons for Gain, Setup and Gamma controls. See 11. sparkPrimatte Tools and Buttons for more information about using these new features.
This button (located in the Cntl 4 tab) opens a window that displays the Primatte algorithms and allows the user to see what is happening as he uses the various Primatte tools. It is a passive feature that has no adjustment capabilities, it may prove useful in evaluating an image as you operate on it.
When you select it, you are presented with a window that may look similar to one of these images (depending on which Primatte algorithm you have selected)...
The different algorithms are described in more detail in the next section of this manual. Here is a description of the tools and features of the 3D Viewer:
At the top of the 3D Viewer window
are three areas that can be clicked on:
1. Clicking and dragging on the blue center area allows the user to move the window around on the screen.
2. Clicking and dragging on the triangular white region in the upper right corner allows the user to scale the 3D Viewer window.
3. Clicking on the square white region in the upper left of the window displays a pop-up menu that looks like this...
NOTE: A selected feature has a solid yellow square
next to it. An Unselected feature has a hollow yellow square
next to it.
This feature, when selected, make the 3D Viewer window disappear. Only the Blue bar at the top of the window remains.
This feature, when selected, displays the large Primatte polyhedron in the viewer window.
This feature, when selected, displays the medium Primatte polyhedron in the viewer window.
This feature, when selected, displays the small Primatte polyhedron in the viewer window.
This feature, when selected, makes the selected polyhedrons opaque. De-selecting it makes them semi-transparent.
This feature, when selected, allows the user to sample color regions on the image window using the 3D Sample Operation Mode and see where those regions are in relation to the polyhedron and the algorithm. The colors will be displayed as a spray of pixels in the color selected. This button only allows the user to see or clear the sampled colors.
NOTE: The 3D Sample Operation Mode must be selected for this feature to operate. Click here for details on that tool.
This feature changes the background color of the 3D Viewer window from black (when unselected) to transparent (when selected).
This feature, when selected, slices open the large and medium polyhedrons so that the inner polys can be seen. When unselected, the largest polyhedron selected becomes a completely closed polyhedron and you cannot see the inner polyhedrons (unless the Opaque feature is deselected).
This feature, when selected, changes the polyhedrons from shaded-surface objects to wireframe objects.
14. sparkPrimatte Tools and Buttons
The Auto-Compute tools can be used as the first step in the Primatte operation. It's purpose is to try and do the first three steps of the Primatte operation for you. It will try to automatically detect the backing screen color, remove it and do some clean-up on the foreground and background noise. Even if the clip was shot with an evenly lit, poorly saturated backing screen, the Auto-Compute button should leave you with an image that may only need some spill removal to complete your keying operation.
14a2. Operational Mode Selector Tools
When this operational mode is selected, Primatte gets the sampled backing screen color and then analyzes the original foreground image and determines the foreground areas using the new Primatte V5 foreground detection routine. Then, internally, using the newly determined foreground areas performs the Clean FG Noise operation and determines a more desirable shape for the middle and outer polyhedrons. It then renders the composite using the generated polyhedrons. This does not automatically use the Adjust Lighting functionality as it must be selected in a separate operation.
When this operational mode is selected, the user samples pixels on the image window known to be 100% background. White noisy areas in the 100% background region will become black. This is usually the second step in using Primatte.
When this operational mode is selected, the user samples pixels on the image window known to be 100% foreground. The color of the sampled pixels will be registered by sparkPrimatte to be the same color as in the original foreground image. This will make dark gray areas in the 100% foreground region become white. This is usually the third step in using Primatte.
When this operational mode is selected, the background color component in the sampled pixels (or spill) within the image window is keyed out and removed for the color region selected. This operation can only be used once on a particular color and the amount of spill suppression applied is not adjustable. It is the fastest way to remove spill from a composite image. For more accurate spill suppression, a Fine Tuning (Sliders) or Spill (+) operation should follow or be used instead. This can usually be the fourth (and final) step in using Primatte unless additional adjustments are necessary.
When this operational mode is selected, the sampled color within the image window becomes 100% foreground. However, if the sampled color is already keyed out and removed, it leaves the current 'suppressed' color. It only affects the key or matte information. This tool is usually used to quickly remove stray transparent pixels that have appeared during the chromakeying procedure. It is a quick and easy way to make final adjustments to a composite.
When this operational mode is selected, the color of the sampled pixel within the image window is registered as a reference color for fine tuning. It is displayed in the Color Chip below the Sm. Poly (Detail) slider. To perform the tuning operation, sample a color region on the image, select a Fine Tuning slider and move the slider to achieve the desired effect. See the Fine Tuning Sliders tool descriptions further on in this chapter for more details on slider selection.
When this operational mode is selected, color spill will be returned to the sampled pixel color (and all colors like it) in the amount of one Primatte increment. This tool can be used to move the sampled color more in the direction of the color in the original foreground image. It can be used to nullify a Spill (-) step. This tool dents the Primatte large polyhedron in the color region sampled.
When this operational mode is selected, color spill will be removed from the sampled pixel color (and all colors like it) in the amount of one Primatte increment. If spill color remains, another click using this operational mode tool will remove more of the color spill. Continue using this tool until all color spill has been removed from the sampled color region. This tool expands the Primatte large polyhedron in the color region sampled.
When this operational mode is selected, the matte will be made more opaque for the sampled pixel color (and all colors like it) in the amount of one Primatte increment. If the matte is still too translucent or thin, another click using this operational mode tool will make the sampled color region even more opaque. This can be used to thicken smoke or make a shadow darker to match shadows in the background imagery. It can only make these adjustments to the density of the color region on the original foreground image. It can be used to nullify a Matte (-) step. This tool dents the Primatte medium polyhedron in the color region sampled.
When this operational mode is selected, the matte will be made more translucent for the sampled pixel color (and all colors like it) in the amount of one Primatte increment. If the matte is still too opaque, another click using this operational mode tool will make the sampled color region even more translucent. This can be used to thin out smoke or make a shadow thinner to match shadows in the background imagery. This tool expands the Primatte medium polyhedron in the color region sampled.
When this operational mode is selected, foreground detail will become less visible for the sampled pixel color (and all colors like it) in the amount of one Primatte increment. If there is still too much detail, another click using this operational mode tool will make more of it disappear. This can be used to remove smoke or wisps of hair from the composite. Sample where is visible and it will disappear. This is for moving color regions into the 100% background region. It can be used to nullify a Detail (-) step. This tool expands the Primatte small polyhedron in the color region sampled.
When this operational mode is selected, foreground detail will become more visible for the sampled pixel color (and all colors like it) in the amount of one Primatte increment. If detail is still missing, another click using this operational mode tool will make detail more visible. This can be used to restore lost smoke or wisps of hair. Sample where the smoke or hair just disappears and it will return to visibility. This is for restoring color regions that were moved into the 100% background region. It may start to bring in background noise if shooting conditions were not ideal on the foreground image. This tool dents the Primatte small polyhedron in the color region sampled.
14a2m. Make Foreground Transparent
When this mode is selected, the opaque foreground color region sampled in the image window becomes slightly translucent. This operation is useful for the subtle tuning of foreground objects which are otherwise 100 percent covered with smoke or clouds. It can only be used one time on a particular color. For a more flexible way to thin out a color region and be able to make multiple samples, you should use the Matte (-) tool. It expands the medium polyhedron slightly.
With this mode selected, the completely transparent background region sampled in the image window becomes translucent. This operation is useful for restoring lost hair details, thin wisps of smoke and the like. It shrinks the small polyhedron slightly.
This is the original Select BG Color tool previously found as the default operational mode. When this operational mode is selected, it uses the traditional Primatte method of taking the sampled backing screen color, projecting a line in the opposite direction on the hue wheel and generating artificial pixels that MAY represent the FG object. Then, using the artificially generated foreground pixels internally does the Clean FG Noise operation and creates the shape of the middle and outer polyhedrons. It then renders the composite using the generated polyhedrons. This does not automatically use the Adjust Lighting functionality as it must be selected in a separate operation.
14a3a. Large Polyhedron Slider (Spill Removal)
When in the Fine Tuning (Sliders) operational mode, this slider can be used to remove spill from the registered color region. After choosing the Fine Tuning (Sliders) operational mode and selected a color region, this slider can be moved to remove spill from the registered color region. The more to the right the slider moves, the more spill will be removed. The more to the left the slider moves, the closer the color component of the selected region will be to the color in the original foreground image. If moving the slider all the way to the right does not remove all the spill, re-sample the color region and again move the slider to the right. These slider operations are additive. This result achieved by moving the slider to the right can also be achieved by clicking on the color region using the Spill (-) operational mode. This slider bulges the Primatte large polyhedron near the registered color region.
14a3b. Medium Polyhedron Slider (Transparency)
When in the Fine Tuning (Sliders) operational mode, this slider can be used to make the matte more translucent in the registered color region. After choosing the Fine Tuning (Sliders) operational mode and selected a color region, moving this slider to the right makes the registered color region more transparent. Moving the slider to the left makes the matte more opaque. If moving the slider all the way to the right does not make the color region translucent enough, re-sample the color region and again move the slider to the right. These slider operations are additive. This result achieved by moving the slider to the right can also be achieved by clicking on the color region using the Matte (-) operational mode. This slider bulges the Primatte medium polyhedron near the registered color region.
14a3c. Small Polyhedron Slider (Restore Lost Detail)
When in the Fine Tuning (Sliders) operational mode, this slider can be used to restore lost detail. After choosing the Fine Tuning (Sliders) operational mode and selected a color region, moving this slider to the left makes the registered color region more visible. Moving the slider to the left makes the color region less visible. If moving the slider all the way to the left does not make the color region visible enough, re-sample the color region and again move the slider to the left. These slider operations are additive. This result achieved by moving the slider to the left can also be achieved by clicking on the color region using the Detail (-) operational mode. This shrinks the small polyhedron (which contains all the blue or green background colors) and releases pixels that were close to the background color. The Small Polyhedron Slider in the Fine Tuning (Sliders) mode is useful for restoring pixels that were lost because they were so similar to the background color. This slider dents the Primatte small polyhedron near the registered color region.
This is the display color chip that shows the color selected (or registered) by the Fine Tuning (Sliders) operational mode.
Prior to applying the Adjust Lighting operation, it is necessary to determine the backing screen color using any one of the following operational modes:
1. Simple Select BG Color
2. Smart Select BG Color
3. Auto-Compute
Upon performing one of those operations, the user then clicks on the Adjust Lighting button. Primatte V5 will internally generate an artificial backing screen without the foreground object and use it to generate the pre-processed image that has an evenly lit backing screen behind the foreground object.The default setting of Adjust Lighting should detect all the areas of the adjust lighting grid that contain foreground pixels and deliver a smooth 'artificially created' optimized backing screen for the keying. Should it fail to do this, the user can adjust the settings of the algorithm by selecting the Adjust Lighting mode and then moving the Lighting s-poly slider. The user can then see the result of the lighting adjustment by selecting Cntl 2 tab and clicking on the Auto Backing Screen button. This displays the optimized artificial backing screen that the Adjust Lighting mode creates. By again using one of the operations that sample the backing screen color (listed above), the new results will be visible. This operation can be repeated until a smooth, evenly lit optimized artificial backing screen is created.
After sampling the backing screen color and finding that the edges of the foreground object look very good, you sometimes find that an area of the foreground object is transparent. This is due to the foreground containing a color that is close to the backing screen color. When this transparency is removed using the Clean FG Noise operational mode, the edge of the foreground object picks up a fringe that is close to the backing screen color and it is very hard to remove without sacrificing quality somewhere else on the image. The Hybrid Render mode internally creates two keying operations - Body and Edge. The Edge operation is optimized around getting the best edge around the foreground object without any fringe effect. The Body operation is used to deal with the transparency within the foreground object. The resultant matte is created by combining these two mattes, Body and Edge, by blurring and then eroding the foreground object in the Body operation and then combining it with the matte created in the Edge operation.
The user first keys the main foreground area using the Smart Select BG Color mode (or any of the other Primatte backing screen detection methods) until a good result is obtained with good edges around the foreground object. Then the user selects the Hybrid Render button and chooses the Clean FG Noise operational mode. When the transparent area is then sampled, the Primatte V5 Hybrid Render mode will internally perform the ‘Body/Edge’ operation. This results in a final composite with good edges around the foreground object while still preserving the area within the foreground object that was transparent.14a4. Miscellaneous Ctrl 1 Page Buttons
This button exits the Primatte spark and returns to the Effects menu options.
This changes the view in the image window to the Composite image.
Exits sparkPrimatte and changes the menu to the Setup menu. From here, the user can save and load sparkPrimatte's key parameter data as 'data sets'.
Used to display the main sparkPrimatte tool window. This where the users executes the Primate operation.
Used to access the Foreground Color Correction tools.This also has the Hybrid Matte
view button and the Auto Backing Screen
view button.
Used to display the Background Color Correction tools. This also has the Hybrid Erode
slider and the Hybrid Blur
slider.
Used to access the 3D Viewer
button, the Help
button and the Crop Window tools. The 3D Viewer allows the user to see the Primatte algorithm graphically. The Help buttoms open a browser and displays this manual. The Crop Tools allow the user to set a rectangular cropping region for garbage matting purposes.
Starts the automated rendering for sequential images.
This button is used to transfer sparkPrimatte information to the Autodesk M&E Action module. Perform the sparkPrimatte operation to create a final composite, create a matte by selecting the Matte Output button and the Process button. Create a Processed FG output by selecting the Proc'ed FG Output button and the Process button. These two pictures (clips) should then be imported to the Action module. You can also save the Processed Foreground image output as clip images by selecting this button. It is the color processed foreground which can be used (with the mask channel image) in Quick Composite, Compositor or Action function in the flame/flint/fire/inferno/smoke menu. The main purpose being for "Multi-layering". If the customer is using the matte and FG to composite pictures in the Action module, a bluish edge may appear in the resulting image. The customer should use the matte and processed (or blue-suppressed) foreground for the best results. Although the Proc'ed FG Output may look noisy in the image widow (depending on the spill replacement mode selected), it will be processed properly and deliver the desired results.
Determines the degree of background penetration into the foreground around the silhouette of the foreground object.
Note: With using this feature, foreground details and smoothness of motion blur may be adversely affected. Set it to 0 for optimum results.
Determines the defocusing level being applied to the matte. When using this tool, some noise may appear around the edges of the foreground object. To avoid this problem, toggle the to the Solid Color Replacement mode.
Note: With using this feature, foreground details and smoothness of motion blur may be adversely affected. Set it to 0 for optimum results.
Cancels the previous Primatte operation. Up to 2000 levels of Undo/Redo are supported.
Redoes the previous operation. Up to 2000 levels of Undo/Redo are supported.
Resets all of the Primatte key control data.
14a4o. Rectangle/Median/Point/Snail Trail Sample Selector
This button allows the user to choose between a Median Point sample, an interactive Rectangular pixel selector or to sample using a Snail Trail 'click and drag' method.
14a4o1. Median Point Sample
The Median Point selection mode is the same as Point selection except that each point is the result of taking a 3x3 region around the point the user clicked and then applying a median filter. This can potentially reduce any noisy pixels.
14a4o2. Rectangular Sample
When Bounding Box is selected, the user clicks and drags to create a rectangular selection area. When using the Select BG Color, Spill +/-, Detail +/-, Matte +/- tools, the selection is then created from the average of all the pixels in the rectangular area. The rest of the operations (e.g. Clean BG Noise, Clean FG Noise, etc.), take account of all the pixels in the rectangular region.
14a4o3. Point or 'Snail Trail' Sample
A Point or 'Snail Trail' selection is like a trail of pixels selected as the cursor moves over the image. Point selection is similar to Bounding Box, so it is either averages or uses all the pixel information of the trail dependent on the operation.
14a4p. Complement/Solid/Defocus Spill Replacement
Allows the user to choose between the three methods of color spill replacement:
14a4p1. Complemental Replacement - Replaces the spill color with the complement of the backing screen color.
14a4p2. Solid Color Replacement - Replaces the spill color with a 'user selected' solid color.
14a4p3. Defocus Replacement - Replaces the spill color with colors from a defocused version of the background image.
14a4q. Solid Color Spill Replacement Color Chip
This color chip displays the current Solid Color Spill Replacement Color (by default, it is gray; R128, G128, B128). By clicking on this color chip, the Solid Color Replacement Color selector window is displayed in the lower right corner of the display monitor allowing the user to select a solid color to be used in replacing colorspill when using the Solid Color Replacement method.
14a4r. Linear/Log Image Colorspace
Selects between Log image file or Linear image file.
This changes the image view in the main image view window to the Matte View. It should also be used to toggle back to the Composite View.
With most sparkPrimatte operations, computation and redrawing of images are automatically executed. With this switch turned on, automatic computation and redrawing are suppressed, with the current picture remaining on the main image view window. The user can then perform several sparkPrimatte operations, but they will not be performed on the image until this button is selected again. This feature is useful for saving processing time, for example, when you are removing background noise on a pixel by pixel basis in Clean BG Noise mode.
This button allows the user to select which Primatte algorithm to use. there are three to choose from. Primatte RT and Primatte RT+ are simpler versions of the full Primatte algorithm and might be able to be used instead of the full Primatte algorithm if the backing screen is very well lit and has even saturation across the entire surface. See Section 17 for more information about the different Primatte algorithms and how they work.
14a4u1. Primatte RT+ algorithm differs from the Primatte algorithm in that it has a six surface color separator instead of the 127-faceted polyhedrons. This makes the Primatte RT+ algorithm much simpler and, therefore, faster to calculate.
14a4u2. Primatte RT is the simplest algorithm and, therefore, the fastest. It uses only a single planar surface to separate the 3D RGB colorspace and, as a result, does not have the ability to separate out the foreground from the backing screen as carefully as the full Primatte algorithm.
14a4u3. Primatte is the full Primatte algorithm using the multi-faceted polyhedrons. It takes the most calculation but delivers the best results.
This activates the External Matte clip (if one has been created and attached). The white area of the third input to sparkPrimatte will be classified as 100% transparent regardless of the original FG information.
The external matte image can be inverted by clicking on the Invert Ext.Mat. button. With this button highlighted (pushed), the black area in the image of external matte input will be processed as the complete background pixel.
This feature forces the blur inward toward the center of the foreground subject. The conventional matte blur feature affected the matte edges in both directions (inward and outward) and sometimes introduced a halo artifact around the object edge in the composite view. This was most evident when using the Complemental Replacement mode. With the Inward Defocus switch ON, the matte defocus functions only in the inward direction of the foreground subject (toward the center of the white area). The final result is that it removes small and dark noise in the backing area without picking them up again in the Clean BG Noise mode and sometimes results in softer, cleaner edges on the foreground objects.
The Grain Tools are used when a foreground image is highly compromised by film grain. As a result of the grain, when backing screen noise is completely removed, the edges of the foreground object often become harsh and jagged leading to a poor key. These tools were created to, hopefully, help when a compositing artist is faced with a grainy image.
The Grain Size selector gives the user a range of grain removal from Small to Large. The use of this tool is explained further along in this section.
When the Grain Size tool
If the foreground image has a large amount of film grain induced pixel noise, you may loose a good edge to the foreground object when trying to clean all the grain noise with the Clean BG Noise Operation Mode. These tools allow the user t clean us the grain noise without affecting the quality of the key. A short tutorial explaining when and how to use these tools is at the end of this section. Click here to go to the tutorial.
When None is selected, the user gets the color of the exact pixel sampled.
When Small is selected, the user gets the average color of a small region of the area around the sampled pixel. This should be used when the grain is very dense.
When Medium is selected, the user gets the average color of a medium-sized region of the area around the sampled pixel. This should be used when the grain is less dense.
When Large is selected, the user gets the average color of a larger region of the area around the sampled pixel. This should be used when the grain is very loose.
Adjusting this slider this should increase the affect of the Clean BG Noise tool without changing the edge of the foreground object.
Selecting this option displays the artificial backing screen that is used as a reference when keying the foreground object against an unevenly lit backing screen. This image can be displayed when this option is selected whether the Adjust Lighting feature has been activated or not.
This displays the internally generated Body matte that has been automatically generated when using the Hybrid Mode.
Resets all Color Correction adjustments to both Foreground and Background images.
Resets all Color Correction adjustments to Foreground images.
Allows adjustment to Hue, Saturation and Luminance values of the Foreground image.
Resets adjustments to Hue, Saturation and Luminance values of the Foreground image.
Gang adjusts RGB Gain values of the Foreground image.
Allows adjustment to RGB Gain values of the Foreground image.
Resets adjustments to RGB Gain values of the Foreground image.
Gang adjusts RGB Setup values of the Foreground image.
Allows adjustment to RGB Setup values of the Foreground image.
Resets adjustments to RGB Setup values of the Foreground image.
Gang adjusts RGB Gamma values of the Foreground image.
Allows adjustment to RGB Gamma values of the Foreground image.
Resets adjustments to RGB Gamma values of the Foreground image.
This slider (located under the Cntl 3 tab) allows the user to adjust the amount of blur applied to the Hybrid Matte. The results can be viewed if the Hybrid Matte button has been activated.
This slider (located under the Cntl 3 tab) allows the user to adjust the amount of erosion applied to the Hybrid Matte. The results can be viewed if the Hybrid Matte button has been activated.
Resets all Color Correction adjustments to Background images.
Allows adjustment to Hue, Saturation and Luminance values of the Background image.
Resets adjustments to Hue, Saturation and Luminance values of the Background image.
Gang adjusts RGB Gain values of the Background image.
Allows adjustment to RGB Gain values of the Background image.
Resets adjustments to RGB Gain values of the Background image.
Gang adjusts RGB Setup values of the Background image.
Allows adjustment to RGB Setup values of the Background image.
Resets adjustments to RGB Setup values of the Background image.
Gang adjusts RGB Gamma values of the Background image.
Allows adjustment to RGB Gamma values of the Background image.
Resets adjustments to RGB Gamma values of the Background image.
These 4 sliders are used to create a rectangular garbage matte. All pixels outside of the rectangle will be forced to 100% background pixels.
Resets the crop rectangle.
This opens a browser window and displays this Help manual.
This opens the 3D View Monitor window. for more information on this feature, see Section 11. The 3D View Monitor.
15a. Essential Files: These files are required for proper sparkPrimatte operation.
PrimatteV4.spark - This is the sparkPrimatte plug-in. It will be in the /usr/discreet/sparks/PRIMATTE directory.
prim4.txt - This is the NodeLock license key text file. If Photron had your system information (sysinfo -s), you should have been faxed or e-mailed a license key. If not, you must contact Photron as per in Chapter 3 Getting and Installing a License Key. The Primatte NodeLock license should always be installed in the /usr/local/etc directory.
Prim_Manual.htm - This is the document you are reading.
15b. Optional files: These files are included on sparkPrimatte CDs, but are optional downloads on the web site.
/IMG - This is a directory with sample images. When used in conjunction with this tutorial, a working knowledge of the sparkPrimatte operation can be achieved.
alex-fg.tif - This is a foreground image of a girl against a bluescreen (640x480 pixels).
alex-bg.tif - This is a background image of a street scene (640x480 pixels).
tabako-fg.tif - This is a foreground image of cigarettes in an ashtray (640x480 pixels).
tabako-bg.tif - This is a background image of a tabletop (640x480 pixels).
water-fg.tif - This is a foreground image of a statue with water cascading (640x480 pixels).
water-bg.tif - This is a background image of a clocktower (640x480 pixels).
/ANIM - This is a sequence of images saved as alex01.rgb to alex20.rgb (640x480 pixels).
16. More about the Primatte Polyhedral Slicing Algorithm
There are three Primatte algorithms. Here is a chart that shows the main differences between them...
For a description of the Primatte algorithm, go to Section 10a. or click here.
For a description of the Primatte RT+ algorithm, go to Section 10b. or click here.
For a description of the Primatte RT algorithm, go to Section 10c. or click here.
16a. Explanation of how Primatte works...
The Primatte chromakey algorithm is a sophisticated method of color space segmentation that can be easily explained to help a user achieve maximum effectiveness with the tool. Basically Primatte segments all the colors in the foreground image into one of four separate categories. The result is a 'spill suppressed' foreground image and a matte which is used to apply the modified foreground to a suitable background.
Primatte works in 3D RGB color space. Here is a visual representation of the Primatte algorithm after an image has been processed.
By operating the Primatte interface, the user essentially creates three concentric, multi-faceted polyhedrons. These can be pictured as three globes (or polyhedrons or polys), one within the other, which share a common center point. The creation of these polyhedrons separates all possible foreground colors into one of four regions; inside the small polyhedron (1), between the small and medium polyhedrons (2), between the medium and the large polyhedrons (3) and outside the large polyhedron (4).
The four regions created are described as follows:
Region 1 (inside the small polyhedron) - This region contains all of the foreground image colors that are considered 100% background. These are the green or blue or whatever colors that were used as the backing color of the foreground image.
Region 2 (between the small and medium polyhedrons) - This region contains all the foreground colors that are at the edges of the foreground object(s), in glass, glass reflections, shadows, sheets of water and other transparent and semi-transparent color regions. These color regions also have spill suppression applied to them to remove color spill from the backing screen.
Region 3 (between the medium and large polyhedrons) - This region contains all the foreground image colors that are 100% foreground but have spill suppression applied to them to remove color spill from the backing screen. Otherwise they are 100% solid foreground colors.
Region 4 (outside the large polyhedron) - This region contains all the 100% foreground image colors that are not modified from the original foreground image. There is no spill suppression applied to these colors.
In the first step in using Primatte (Select BG Color), the user is asked to indicate the backing color on the original foreground image. The sample should usually be taken from a 'medium shaded' area near the foreground object. By 'medium shaded' area, it is meant that if green is the backing color and the green area of the foreground image has many shades of green ranging from very pale green to almost black, a shade of green in-between these extreme ranges should be chosen. If good results are not obtained using this sample, Primatte should be reset and another sample taken using a slightly darker or lighter shade of green. The first sample of Primatte often determines the final result as the center point of all three polyhedrons is created based on this first sample.
A single pixel may be selected or a range of pixels (snail trail or rectangular sample). If a range of pixels is taken, the sample will be averaged to get a single color sample. This single pixel or averaged color sample then becomes the center of the small polyhedron. A few other shades around that color are included in the original small polyhedron.
NOTE: It is recommended that a single pixel be selected as the first sample as you then have some idea where the center point of the polyhedrons is located. If a box sample or a long snail trail sample is made. You can only guess at the average color that ends up being the center point. You can get an idea how this sample affects the algorithm by resetting the Primatte plug-in, going to the Matte View and clicking around on the green or blue screen area while in the Select BG Color Operation Mode. You can immediately see the results of the initial settings of the polyhedrons in this way.
After making a sample of the backing screen color in the first step, the result is a small golf ball-shaped poly as shown in the following image.
The second step in using Primatte is to clean up the backing color area by adding additional shades of green or blue to the small poly. This second step (Clean BG Noise) is usually executed while viewing the black and white Matte View.
Before BG Noise Removal After BG Noise Removal
While in the Clean BG Noise sampling mode, the user samples the white milky regions as shown in the left-hand image above. As the user samples these regions, they turn to black as shown in the right-hand image above.
What is happening in the Primatte algorithm is that these new shades of green (the white milky areas) are added to the small poly where all the shades of green or blue are moved. The next two images show the new pixels sampled (white dots) in relation to the small poly and the image next to it shows how the small poly extends outward to encompass the newly sampled colors into the small poly.
The advantage of this technique is that the polyhedron distorts to enclose only the shades of green that are in the backing screen. Other shades of green around these colors are left undisturbed in the foreground. Other chromakeyers expand from a golf ball-sized shape to a baseball to a basketball to a beach ball. Since it expands in all directions, many shades of green are relegated to 100% background making it hard to get good edges around the foreground objects.
Now that the user has created a small polyhedron, he must shape the medium and large polys. A default medium and large poly are both automatically created and are then modified based on the next couple of Primatte operations. The third Primatte step (Clean FG Noise) is to sample and eliminate gray areas in the 100% foreground area of the image.
Before FG Noise Removal After FG Noise Removal
Again, the user makes several samples on the dark, grayish areas on the foreground object until it is solid white in color. Primatte is shaping the large polyhedron with each color region that is sampled. Care should be taken in both this and the previous steps to not sample too close to the edges of the foreground object. Getting too close to the foreground object's edges will result in hard edges around the foreground object. Primatte uses these samples to modify and shape the medium and large polys to the desired shape. At this point, the matte or key has been created and would allow the foreground objects to be composited into a new background image.
If the user changes the display mode from the black and white Matte View to the color Composite View, there is usually 'color spill' on the edges (and sometimes the center) of the foreground objects. When on the edges of the foreground object, this spill comes from where the edges of the foreground object blended into the backing color. If it is on the center of the foreground object, it usually results from reflected color from the backing screen. The next Primatte step, either Spill Sponge, Fine Tuning or Spill(-), can now be used to eliminate this spill color.
Let's take a look at what is happening in the Primatte algorithm while this next step is performed. Here is what the various tools in Primatte do to the Polyhedrons when they are used:
As you can see above, the Spill Sponge bulges the large polyhedron in the color region specified. A color region is specified by clicking on the image in a particular area with spill present. For example, if the user clicks on some spill on the cheek of a foreground person, Primatte goes to the section of the large polyhedron closest to that particular flesh tone and bulges the polyhedron there. As a result, the flesh tones move from outside the large poly to in-between the medium and large polys. This is Region 3 and, if you remember, is 100% foreground with spill suppression. As a result of the suppression, the spill is removed from that cheek color and all other shades of that color on the foreground. The user would then continue to sample areas of the image where spill exists and each sample would remove spill from another color region.
When all spill has been removed, the user should have a final composite. As a last step, he should go back to the Matte View and make sure that gray, transparent areas have not appeared in the foreground area. If there are any, the Matte Sponge Operation Mode should be selected and those gray pixels are sampled until they have all turned white again.
The Matte Sponge and Spill Sponge tools bulge or dent the polyhedrons a pre-selected amount. If the desired results are not achieved or the results are too extreme for the image, a manual method can be applied. The user should choose the Fine Tuning sliders, select a color region of interest and then move the appropriate slider to get the desired results.
For example, to remove spill, select a region of the composite image with spill on it. Move the spill or large poly slider to the right a little bit, the large poly will bulge and the spill should disappear. Move it a little more, if necessary. Moving this slider to the right removes spill (moves the colors from outside the large poly to between the medium and large polyhedrons) and moving it to the left, dents the large poly and moves that color region to outside the large poly.
If the user samples a foreground object shadow and then moves the Matte or medium poly slider to the right, the shadow will become more transparent. This is useful for matching composited shadows to shadows on the plate photography. It can also be used to make clouds or smoke more transparent.
If some foreground detail disappears during the composite, the user can select where the detail should be and then move the detail or small poly slider to the left. This dents the small poly in that color region and releases the detail pixels from the small poly into the visible region between the small and medium polyhedrons.
The Spill Sponge and Matte Sponge tools are 'shortcut tools' that automatically move the sliders a pre-selected amount as a timesaving step for the user. Other 'shortcut tools' include the Make FG Trans. tool and the Restore Detail tool.
These 'shortcut tools' are one-step operations where the user clicks on a color region of interest and Primatte performs a pre-calculated operation. Hopefully, most operations using Primatte would only require these tools, but the manual operation of the sliders is always an option.
The Spill(-) tool bulges the large poly a small amount incrementally in the color region that is clicked on and the Spill(+) tool dents it a small amount with each click. The Matte(-) and Matte(+) tools do the same to the medium poly and the Detail(-) and Detail(+) do it to the small poly.
16b. Explanation of how Primatte RT+ works...
