Tuesday, March 13, 2012

Color Shading Discussion

Albert Theuwissen discusses color shading measurements in his latest post in "How to measure..." series: "Even if the shading component is small, it can result in (minor) changes in spectral response across the sensor. These type of errors can have a severe effect on colour shading in a colour sensor and can make colour reconstruction pretty complicated. So it absolutely worthwhile to check out the shading under light conditions."


  1. This gets into a thorny area. Looking broadband response per channel is all fine, but is only a small part of the puzzle. One has to consider the integrated response over the spectra of interest, the IR filter (if any) angular response, and the light source spectra. Many factors affect overall color uniformity.

    1. Albert TheuwissenMarch 13, 2012 at 9:45 PM

      Thanks for the comment, you are absolutely right ! In the example shown, I used a 5600K light source, 5 lux on the sensor. The system is not using an IR filter, neither a lens. These conditions were mentioned in the previous blog about PRNU.


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