I have a PhD in cognitive experimental psychology (University of California, 2005) with a specialization in cognitive neurophysiology and visual perception.
Originally Posted by GQB
As an aside, if dithering produces the impression of 'millions of colors', then as far as I'm concerned, it IS millions of colors. Has no one heard of Seurat? The colors are in your brain, not on the screen.
This claim is absolutely correct. The relevant issue here is what the perception of the color on the screen is, not the actual color the screen displays. The method of how you go about reproducing the image in print media from what you have on the display is completely and totally irrelevant to the point here.
The simple fact of the matter is that in the world itself, there is no such thing as "color". Color is a percept created by the functioning of the cone receptors in the retina and the resulting information processing of the neural signal created by the transduction of photons into neurological activity through the deformation of the rhodopsin pigments in the short, medium, and long wavelength receptors. Indeed, the visual system itself uses "dithering" to create the range of "color" that we perceive; each cone has a different spectral peak to which it is sensitive. It is differentials in the activations of those three receptors that are the basis of the percept of any given color. So the basis of all color perception is based only on the responses of only three types of receptors in the retina.
These responses are then interpolated further by the structures in the visual cortex which, to continue to use the computer parlance, is more dithering. Research on color perception and visual neurophysiology has shown that when only a handful of pure wavelengths are displayed, such that there is no continuous frequencies of light contained between them, the visual system will fill in the gaps by activating correlated neurons in the visual cortex that are responsible for creating the perception of those missing colors.
It has also been shown that the greater the number of frequencies in light, the greater the perception of saturation of the color of the light. However, this doesnt mean that were perceiving more colors, we are not. The perception is still based on the responses of three and only three visual receptors, and no amount of increase in the frequencies of light displayed can change that fact. The visual neurons still work the same way, the only difference is how much they respond because of the greater range of frequencies. They still dither the light the receive into the many different colors we perceive.
Once a display displays a range of frequencies that surpasses the ability of the eye to detect differences in the number of frequencies, or the differences in wavelength between them, the issue of how many colors the display produces becomes irrelevant. CRT displays have been able to do that for decades.
People like Clive need to pull their heads out of their arses and get over themselves thinking that the point is how many colors the display actually produces. The idea that anything in the world itself has color is naive and ignorant, as is relying on Wikipedia as an authoritative source to base an argument on. (That also commits the logical fallacy of the appeal to authority.) Actually Clive, you should probably sue God, maybe the Pope while you're at it for their false advertising about how our perception of color in the world is blatant intentional and deceptional false advertising by God and nature...
Also, any professional photographer who takes pride in the fact that theyre a professional would know these simple facts about how humans perceive color, and their concern would be more with the process of how to accurately reproduce in printed media the image theyre concerned with. Once you get above a certain level of display quality, the display itself is a non-issue. Again, a large body of psychophysical research on color perception has been done that proves this point, although Im sure that again, people like Clive will simply choose not to believe this so they can go on with their hating.
This lawsuit was nothing more than greed and publicity for the people who filed it. It has no basis in empirical fact about how color is perceived by the human visual system. Im amazed that Apple caved on it, and didnt simply do some reading in scientific journals such as Journal of Experimental Psychology; Human Perception and Performance, or the journal Perception and Psychophysics, or Vision Research.