To provide a gamma correction method and apparatus for an imaging means capable of automatically creating a lookup table with high accuracy for gamma correction for a CCD camera or the like in units of pixels without using an auxiliary tool.
A flowchart indicating creating procedures of the lookup table for gamma correction includes: steps 1 to 7 of individually selecting all pixels P of a CCD camera in a prescribed sequence and deciding a base exposure time at which a unit output is obtained from the pixels selected sequentially when imaging under a prescribed illumination; steps 8 to 16 of setting an integer multiple of the decided base exposure time S[P] from the selected pixel to a real exposure time S and measuring an output value of the pixel through imaging under the illumination by each set real exposure time; a step 17 of creating the lookup table wherein each measured output value by each pixel is recorded in cross-reference with each input value comprising an integer used for calculation of the corresponding real exposure time; and applying the gamma correction to the CCD camera in units of pixels on the basis of the created lookup table.
OKAZAWA ATSUSHI
Keisuke Matsuyama
Tsuyoshi Makino
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