Gamma Correction in the SGI Performer Library

SGI Performer
The SGI Performer Library has a built in software gamma correction of 1.4. Combined with the SGI's built-in hardware correction of 1.7, this means that texture patterns (or other images) prepared for display on the SGI with the Performer Library should be gamma corrected to 1.0

Unfortunately, storing image data that is gamma corrected to 1.0 leads to a less than optimal dynamic range of image data. (1.0 really represents no gamma correction since it is "corrected" to the 1/1 power.) The human perception of light intensity is closer to a gamma setting of 3.0, (see Wyszecki and Stiles, Color Science: Concepts and Methods, Quantitative Data and Formulae, page 167 for the actual formula) This means that to get the greatest dynamic range across the space of human perception, the data should be stored in the file after applying a gamma correction nearer to 2.5. Such data would not require much further correction when it is time to display it on most computer systems. The reason SGI set up the system to use 1.0 corrected files is for computational speed.