Returns the mapping from the raw values of samples (from GetSamplesAt(Int32)) to colour
components: DecodeMap, at 8 bits when a reduction turned samples of fewer bits (a 1-bit scan, a 4-bit image)
into 8-bit averages.
public ImageDecodeMap DecodeMapFor(DisplayImageSamples samples)
Samples of this image.
ISO 32000-2 §8.9.5.2, Table 88: linear, so the mean of raw values maps to the mean of their component values.