what excaxtly the gray2ind does?

in the descripion it says- gray2ind scales and then rounds the intensity image to produce an equivalent indexed image. but what does it do compare to uniformal quantization? if uniformal quantization of 2 levels would send all the values to 0 and 127 , the gray2ind sends all the values to 0 and 255.. for 16 levels it does 16 levels but starts from 17 now and not 0... so whats the logic in this function quantization?

Answer 1

[Image Analyst]

I don't see any use for this function in the way that you described. Why do you want to use it that way? It's main purpose is to reduce the number of gray levels in an image. Here's an explanation of the concept using color images: http://en.wikipedia.org/wiki/Color_quantization