Linking Digital Image Operations to Physics
What we perceive as color is electromagnetic radiation coming off a surface as a spectral power distribution. A tomato appears red because its surface reflects radiation mostly around 700 nm. The human eye has three kinds of color‑sensitive cells for perceiving color: short, medium, and long wavelength cones, each sensitive to wavelengths that correspond roughly to blue, green, and red channels. We mathematically model this for digital display by projecting the spectrum onto a three‑dimensional color space. Projecting an infinite‑dimensional spectrum onto a three‑dimensional space results in the loss of information and leads to metamers (different spectra with the same RGB). ...