Chapter 4

More details on gamma correction for publication on the WWW can be found from the link

http://www.cgsd.com/papers/gamma.web.html

The full specification of the new sRGB standard color space for WWW applications can be viewed from

http://www.w3.org/Graphics/Color/sRGB

See

http://vera.inforamp.net/~poynton/PDFs/coloureq.pdf

for a link to an excellent review of color transforms.

See

http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html

for a much-quoted standard FAQ file on color.

The new MPEG standard, MPEG-7 is discussed in Chapter 12. That standard somewhat sidesteps the thorny question of whose favorite color space to use in a standard definition by including six color spaces. One of them is a new variant on HSV space, called HMMD Color Space, that purports to allow a simple color quantization, from 24-bit down to 8-bit color, say, that is effectively equivalent to a complex vector color quantization (i.e., considering a more careful, but also more expensive mapping of the colors in an image into the color LUT). This new color space may indeed become important: it can be explored at

http://www.lgcit.com/MIGR/cmip/hmmd/hmmd.html

A Matlab script to exercise (and expand upon) the color transform functions that are part of the Image Toolbox in Matlab: the standard `Lena' image is transformed to YIQ and to YCbCr.

colortransforms.m

lena.jpg

lenayiq.jpg

lenaycbcr.jpg