Transform an image or colormap from red-green-blue (RGB) color space to a grayscale intensity image.
The input may be of class uint8, int8, uint16, int16, single, or double. The output is of the same class as the input.
Implementation Note: The grayscale intensity is calculated as
I = 0.298936*R + 0.587043*G + 0.114021*B
which corresponds to the luminance channel when RGB is translated to YIQ as documented in https://en.wikipedia.org/wiki/YIQ.
See also: rgb2hsv, rgb2ind.
Package: image