Identifies an NSNumber object containing the gamma value for the image.
Used only for PNG files. The gamma values is a floating-point number between 0.0 and 1.0, with 0.0 being black and 1.0 being the maximum color. It’s set when reading in and used when writing out.
Available in Mac OS X v10.4 and later.
- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)