| 摘要 |
<p>PROBLEM TO BE SOLVED: To change a gamma value only against a specific luminance level and to obtain a gamma correcting circuit that obtains a desired specific result on a screen by measuring gamma that matches a picture tube characteristic and applying the optimum gamma value by many gamma characteristics. SOLUTION: This circuit has a prescribed number of lookup tables 20 which contain a gamma coefficient set consisting of a prescribed number of gamma characteristics that correspond to many input color signals. One of lookup table that correspond to each input color signal is selected by a selective control signal, the selected lookup table changes the gamma value of luminance component of a color signal, and the color signal that is performed gamma correction is outputted. For example, when an inputted luminance signal has an inverse gamma characteristic like a', the first lookup table of each channel of storing part 20 stores a gamma coefficient consisting of a gamma characteristic like an inverse relation characteristic against the inverse gamma characteristic a'. The second lookup table of each channel of the part 20 stores a gamma coefficient consisting of a gamma characteristic like b.</p> |
