Lecture 19: Intro To Color Science (116)
he-yilan

why are RGB the three basis vectors in computer graphics while we are taught that the primary colors used to make all other colors are red, blue, and yellow? i was curious about this so i looked into it and found the answer was more complex than i thought. RYB comes from the subtractive color theory in which colors absorb light rather than emit light. technically, this trio should be cyan, magenta, and yellow. but in society and our teachings about color theory at the elementary level, this has been adapted to be blue, red, and yellow. on the other hand, additive color theory is based on the idea that colors produce light; this is the way that computers work, as computer graphics and colors are shown by being displayed by light on a computer screen. in this theory, combinations of red, green, and blue has been found to produce all other colors. therefore, using additive color theory, computers use the basis vectors of RGB. sources: https://medium.com/nerd-for-tech/the-color-theory-why-do-computers-use-rgb-instead-of-ryb-205b75d6e783#:~:text=The%20additive%20is%20the%20case,other%20light%2Demitting%20screen%20works.

https://www.wtamu.edu/~cbaird/sq/2015/01/22/why-are-red-yellow-and-blue-the-primary-colors-in-painting-but-computer-screens-use-red-green-and-blue/

colinsteidtmann

I looked up what "Quantal efficiency" is and found its the probability of a photon at a specific wavelength being absorbed by a cone cell and triggering a response. It's interesting how the S cone cell has a much lower quantal efficiency compared to the medium and long cone cells. I looked this up and found this difference in quantal efficiency might be due to the different types of opsins (light-sensitive proteins) present in each type of cone cell.

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