Apple Shake 4 - Manual (Page 437)

Chapter 15 Image Processing Basics 437
The Logarithmic Cineon File
Kodak created the Cineon file format to support their line of scanners and recorders.
Two things are typically associated with the Cineon file: the Cineon file itself (an
uncompressed 10-bit image file) and the file’s particular color representation. When
graphed, this representation takes the form of a logarithmic curve, hence the term
“logarithmic color” (or “log” for short). Although some refer to it as a “log space,” it is
not actually a “space” such as YUV, RGB, or HSV.
Note: (A caveat, if you will.) This section is to be treated only as an overview of a
subject that causes flame wars of such staggering proportions that everybody walks
away dazed and filled with fear and loathing. You have been warned.
The image set below represents linear space—every value has an equal mathematical
distance in brightness to its neighbor.
The following image set represents a ramp converted to logarithmic color, where the
brightness is weighted.
Linear image Graph
Logarithmic image Graph