cat foo.gif | giftopnm | ppmhist -noheader -hexcolors | awk '{ print "rgb:"$1"/"$2"/"$3 }'
lhe dará uma lista de todas as cores no formato X11 rgb: r / g / b.
Sou fã de potrace e recentemente li as Perguntas frequentes sobre o Potrace .
O FAQ inclui este belo one-liner:
cat img.gif | giftopnm | ppmcolormask #641b1b | potrace
O comando que estou procurando retornaria os códigos de todas as cores a serem analisadas por ppmcolormask . Ele poderia retornar, de acordo com man ppmcolormask :
You can specify color five ways:
o An X11-style color name (e.g. black).
o An X11-style hexadecimal specifier: rgb:r/g/b, where r g and b
are each 1- to 4-digit hexadecimal numbers.
o An X11-style decimal specifier: rgbi:r/g/b, where r g and b are
floating point numbers between 0 and 1.
o For backwards compatibility, an old-X11-style hexadecimal num‐
ber: #rgb, #rrggbb, #rrrgggbbb, or #rrrrggggbbbb.
o For backwards compatibility, a triplet of numbers separated by
commas: r,g,b, where r g and b are floating point numbers
between 0 and 1. (This style was added before MIT came up with
the similar rgbi style.)
Tags image-manipulation netpbm