1-Consciousness-Sense-Vision-Color Vision-Parameters

chromaticity

Color perception depends on hue, saturation, and brightness. Mostly hue and saturation {chromaticity} make colors. Brightness does not affect chromaticity much [Kandel et al., 1991] [Thompson, 1995].

hue

Spectral colors depend on light wavelength and frequency {hue}. People can distinguish 160 hues, from light of wavelength 400 nm to 700 nm. Therefore, people can distinguish colors differing by approximately 2 nm of wavelength.

color mixtures

Hue can come from light of one wavelength or light mixtures with different wavelengths. Hue takes the weighted average of the wavelengths. Assume colors can have brightness 0 to 100. If red is 100, green is 0, and blue is 0, hue is red at maximum brightness. If red is 50, green is 0, and blue is 0, hue is red at half maximum brightness. If red is 25, green is 0, and blue is 0, hue is red at quarter maximum brightness.

If red is 100, green is 100, and blue is 0, hue is yellow at maximum brightness. If red is 50, green is 50, and blue is 0, hue is yellow at half maximum brightness. If red is 25, green is 25, and blue is 0, hue is yellow at quarter maximum brightness.

If red is 100, green is 50, and blue is 0, hue is orange at maximum brightness. If red is 50, green is 25, and blue is 0, hue is orange at half maximum brightness. If red is 24, green is 12, and blue is 0, hue is orange at quarter maximum brightness.

lightness

Fraction of incident light transmitted or reflected diffusely {lightness} {luminance factor}. Lightness sums the three primary-color (red, green, and blue) brightnesses. Assume each color can have brightness 0 to 100. For example, if red is 100, green is 100, and blue is 100, lightness is maximum brightness. If red is 100, green is 100, and blue is 50, lightness is 83% maximum brightness. If red is 100, green is 50, and blue is 50, lightness is 67% maximum brightness. If red is 67, green is 17, and blue is 17, lightness is 33% maximum brightness. If red is 17, green is 17, and blue is 17, lightness is 17% maximum brightness.

saturation of color

Pure saturated color {saturation, color}| {purity, color} has no white, gray, or black. White, gray, and black have zero purity. Spectral colors can have different white, gray, or black percentages (unsaturation). Saturated pigments mixed with black make dark colors, like ochre. Saturated pigments mixed with white make light pastel colors, like pink.

frequency range

The purest most-saturated color has light with one wavelength. Saturated color pigments reflect light with narrow wavelength range. Unsaturated pigments reflect light with wide wavelength range.

colors and saturation

All spectral colors can mix with white. White is lightest and looks least saturated. Yellow is the lightest color. Monochromatic yellows have largest saturation range (as in Munsell color system), change least as saturation changes, and look least saturated (most white) at all saturation levels. Green is second-lightest color. Monochromatic greens have second-largest saturation range, change second-least as saturation changes, and look second-least saturated (second-most white) at all saturation levels. Red is third-lightest color. Monochromatic reds have average saturation range, change third-least as saturation changes, and look third-least saturated (third-most white) at all saturation levels. Blue is darkest color. Monochromatic blues have smallest saturation range, change most as saturation changes, and look fourth-least saturated (least white) at all saturation levels. Black is darkest and looks most saturated.

calculation

Whiteness, grayness, and blackness have all three primary colors (red, green, and blue) in equal amounts. Whiteness, grayness, or blackness level is brightness of lowest-level primary color times three. Subtracting the lowest level from all three primary colors and summing the two highest calculates hue brightness. Total brightness sums primary-color brightnesses. Saturation is hue brightness divided by brightness. Assume colors can have brightness 0 to 100. If red is 100, green is 100, and blue is 100, whiteness is maximum. If red is 50, green is 50, and blue is 50, grayness is half maximum. If red is 25, green is 25, and blue is 25, grayness is quarter maximum.

Assume maximum brightness is 100%. If red is 33%, green is 33%, and blue is 33%, brightness is 100% = (33% + 33% + 33%), whiteness is 100% = (33% + 33% + 33%), hue is white at 0%, and saturation is 0% = (0% / 100%). If red is 17%, green is 17%, and blue is 17%, brightness is 50% = (17% + 17% + 17%), whiteness is 50% = (17% + 17% + 17%), hue is white at 0%, and saturation is 0% = (0% / 50%). If red is 33%, green is 33%, and blue is 17%, brightness is 83% = (33% + 33% + 17%), whiteness is 50% = (17% + 17% + 17%), hue is yellow at 33% = (33% - 17%) + (33% - 17%), and saturation is 40% = (33% / 83%). If red is 67%, green is 17%, and blue is 17%, brightness is 100% = (67% + 17% + 17%), whiteness is 50% = (17% + 17% + 17%), hue is red at 50% = (67% - 17%), and saturation is 50% = (50% / 100%). If red is 100%, green is 0%, and blue is 0%, brightness is 100% = (100% + 0% + 0%), whiteness is 0% = (0% + 0% + 0%), hue is red at 100% = (100% - 0%), and saturation is 100% = (100% / 100%).

Assume colors can have brightness 0 to 100. If red is 100, green is 50, and blue is 50, red is 50 = 100 - 50, green is 0 = 50 - 50, blue is 0 = 50 - 50, brightness is 200, whiteness is 150 = 50 + 50 + 50, and hue is pink with red saturation of 25 = 50 / 200. If red is 100, green is 100, and blue is 50, red is 50 = 100 - 50, green is 50 = 100 - 50, blue is 0 = 50 - 50, brightness is 250, whiteness is 150 = 50 + 50 + 50, and hue is yellow with saturation of 40% = (50 + 50) / 100 = 100 / 250. If red is 75, green is 50, and blue is 25, red is 50 = 75 - 25, green is 25 = 50 - 25, blue is 0 = 25 - 25, brightness is 150, whiteness is 75 = 25 + 25 + 25, and hue is orange with saturation of 50% = (50 + 25) / 150 = 75 / 150.