Computer Vision Foundations · free preview
Three Cones and Metamers
Three cone classes project the spectrum to three numbers, which makes color matching possible and metamerism inevitable.
1. The eye keeps three numbers
The eye keeps three numbers
2. The response is a projection
The response is a projection
3. Matching with three primaries
Matching with three primaries
4. Metamers
Metamers
5. What the projection discards
Two lights have very different spectra, one spiky and one smooth, yet they look identical to a human observer. What is the correct explanation?
6. Why three primaries are enough
A display must reproduce the appearance of an arbitrary light using mixtures of three fixed primaries. Why does the cone projection guarantee this is possible in principle?
7. One cone's response
A simplified cone has sensitivities across three sampled wavelengths, and an incoming spectrum has intensities at those samples. Write the cone's response as a number.
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