You might be wondering why I'm discussing computer generated imagery (CGI), games and video here since the rest of the pages were clearly focused on the web. The answer is simple, the gamma you choose for your system gamma will affect these things.

CGI is created by modeling the way light behaves as it interacts with objects. This interaction is linear. The programs that create the most realistic CGI are called ray-tracers. They generate the images by modeling the actuall physics of light. These images can take anywhere from minutes to days to create. The images created by these programs should be saved in their natural linear domain, leaving any gamma correction to the last stage when it gets saved for the web or put into a video.

Modern 3D computer games are really just a special subset of CGI. They use simpler calculations to generate shading, reflections, and transparency in real time. Most of this is done by hardware on the graphics card. The calculations are still done in the linear domain. Many of these games have gamma adjustments so that the user can get the image to look right. Whether these controls affect something in the rendering pipeline or the LUT_gamma I don't know. If that adjustment affects the rendering pipeline, then it could be slowing down the rendering by adding another caluculation to each pixel rendered. I do know that opengl apps on linux are affected by the system gamma setting.

Video display and editing poses yet another series of problems. For the most part video display done by mediaplayer or programs using the xvideo extension are not affected by the system gamma. This occurs because they are using a video overlay that bypasses the framebuffer and LUT. I know that at least some video editors and capture systems actually put the video into the framebuffer which means it would be affected by gamma. The good knews is that by international agreement the HDTV spec uses srgb. So if your doing video editing I would suggest setting your system gamma to 2.2. I wonder if any of those editors or viewers would use the CMS when displaying video through the framebuffer? I really doubt it since each frame would have to be corrected in real time and the CMS is probably to slow to do it.

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