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a) If the color matching functions <math> f_k(\lambda) </math> has negative values, it will result in negative values in <math> F_k </math>. In this case, the color can not be reproduced by this device. | a) If the color matching functions <math> f_k(\lambda) </math> has negative values, it will result in negative values in <math> F_k </math>. In this case, the color can not be reproduced by this device. | ||
| − | b) The CIE color matching functions are not always positive. <math> r_0(\lambda) </math> takes negative values. This is the case because, to match some reference color that is too saturated, colors have to be | + | b) The CIE color matching functions are not always positive. <math> r_0(\lambda) </math> takes negative values. This is the case because, to match some reference color that is too saturated, colors have to be subtracted from the <math> R, G, </math> and <math> B</math> primaries. This results in negative values in tristimulus values r, g, and b. So the color matching functions at the corresponding wavelength have negative values. |
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| + | c) | ||
Revision as of 19:53, 10 November 2014
ECE Ph.D. Qualifying Exam in Communication Networks Signal and Image processing (CS)
Question 5, August 2013, Part 2
part1, part 2
Solution 1:
a) If the color matching functions $ f_k(\lambda) $ has negative values, it will result in negative values in $ F_k $. In this case, the color can not be reproduced by this device.
b) The CIE color matching functions are not always positive. $ r_0(\lambda) $ takes negative values. This is the case because, to match some reference color that is too saturated, colors have to be subtracted from the $ R, G, $ and $ B $ primaries. This results in negative values in tristimulus values r, g, and b. So the color matching functions at the corresponding wavelength have negative values.
c)
