Mac OS X has ImageMagick, right?
$ convert Downloads/photo.png -crop 1x1+9+96 txt:-
# ImageMagick pixel enumeration: 1,1,255,rgba
0,0: ( 0, 74,117,251) #004A75FB rgba(0,74,117,0.984314)
The idea is to crop around a specific pixel, then output it to the special
txt: format, with an output file name of
- which is of course standard output.
You can leave out the the
-crop 1x1+X+Y business to just get a listing of all pixels. Also note that you image must have an alpha channel for this to work, otherwise it just won't get included.