Tuesday, January 16, 2007
Color Spaces & Printer Profiles Revealed
Crayon color choices have some important similarities to how color spaces are defined and used
Back to the Crayola Factory. Imagine 1,000 crayons standing upright, shoulder-to-shoulder. If you were to take a lasso and surround 64 of the adjacent colors that are more or less in the middle of the array, you'd be able to assemble a box of crayons similar to what you used at school. This represents sRGB. But if you were to selectively skip over some of the colors—in fact, remove them from the assortment entirely—and instead include some of the brighter greens and blues, for example, you could put together a very different set. The lasso you used in the first example won't fit around this new set. This new selection of crayons isn't standing shoulder-to-shoulder like the first group—there are a few gaps and the pieces are more spread out. You need a bigger lasso because some of the crayons are farther away from the center.
Adobe RGB has the same number of colors as sRGB, but some of the colors are different. The gamut is wider, and we can say that the color space is larger in the same way that we needed a bigger lasso to harness the crayons in the example above. This explains why Adobe RGB occupies more area on color space diagrams that compare it to sRGB. The same number of colors—but they're more widely dispersed from the central area.
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