Thursday, September 11, 2014

The ABCs of XYZ… Color…



                Humanity has long held the ability to see in high regard. Visual descriptions invade language, entertainment, art (obviously), and numerous other areas. Someone is blind? Help them learn what a visual is, then proceed to describe everything in visual terminology. How does one see “correctly” without being able to “see”? But that’s not the point. The point is, that visuals are very important to humanity. But one of the most important aspects of these visuals is the color. Here’s a cave painting… the color has degraded so now only the ash is left. So there was color even in the earliest moments of humanities struggle to become relevant. But if a visual is so important, and color is an important aspect of visuals, then would not color be the most important?
                Indeed it would. An easy example being the colors used by royalty, such as purple, as it was expensive and hard to produce. So is color standardized? Very much so, but it is young in the realm of visual development, coming to fruition in 1931. The challenge with color is that physics has already defined it as a wavelength of light that is perceptible to humans. There are also standards in pigments used in clothing, art, and numerous other fields. Lastly, its 1931, numerous years have already been spent on defining colors and much of society has already come to agreement on what is certain colors.
                The standardization of color has instead become a definition of what a visual wavelength of light can be perceived as. This is primarily because color is both a physical property and a physiological one. Between various individuals who pioneered light research such as Thomas Young and James Clerk Maxwell defined the colors that the human eye can actually identify as being red, green, and blue.  Originally, Isaac Newton had deducted that red, yellow, and blue were the primary colors and, while evidence exists that yellow is not a primary, it has remained dogma within art and color theory.
                Red, green, and blue became a standard for color definitions, at least informally. But this standard only applies to humans, as animals may/do see different wavelengths of light and thus different colors then humans. For the sake of simplicity, only the human spectrum of visible colors were used for what became known as CIE 1931 RGB color space. This is actually used to derive, and used as a basis for CIE 1931 XYZ color space, which eventually encompassed the RGB color space. What XYZ is defined as is the visible light spectrum, as perceived by humans, onto a 3D plane and visualized as a 2D deformed triangle.
                What made this important, is that there is now a mathematical definition for what we see. Since that time, any electronic device can visualize a specific range of that color. Pigments and colors used in print and any non-electronic device now have a reference color range they can fall back to. An person can look at a computer and say “this is red”, give it to an artist who will say “this is red”, have their car painted and go “this is red” and then, give it to a scientist who will say “this is red”. But it isn’t an interpreted red or a shade or red, it is “red”. The finite mathematical definition of red. If it cannot be mapped to this weird triangle, it cannot be viewed by a majority, if not all of humanity and possible not even by animals.
                This standard has become the basis for numerous other color standards such as CIE RGB, used for computers, CYMK, used for printed media, YCbCr, used for TV, movies, etc., L’A’B’, used by physicists and scientists, and numerous others. As someone who has been doing a lot of work lately with pictures and how to change them from one form to another, without you, the viewer, knowing the images are different, I’ve had to do a lot of studying of this to make sure that everything looks correct and works correctly. It’s not exactly an exciting work, but because of the standard of colors, CIE 1931 XYZ, and the derived color spaces, you’ll never know that any of this is happening, but you’ll also never see it differently across print, electronics, or wherever else you see anything that is colored. Heck, when you close your eyes, the “color” you see is defined and can be visualized too…

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