GRADATION CORRECTION DEVICE, GRADATION CORRECTION METHOD, VIDEO SIGNAL PROCESSOR, AND VIDEO SIGNAL PROCESSING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a gradation correction device capable of realizing higher contrast by smoothing processing of luminance distribution while suppressing occurrence of further insufficient gradation about a video signal in which the insufficient gradation is caused by nonlinear processing, and to provide a gradation correction method.;SOLUTION: Normalization cumulative frequency distribution SS for the smoothing processing of the luminance distribution is generated by using the video signal VI2 having a value equal to or more than a gradation correction restriction parameter CP by a luminance distribution extraction circuit 10 and a switching circuit 11 and the video signal VI2 having the value equal to or more than the gradation correction restriction parameter CP is corrected on the basis of a gradation correction conversion table by a gradation correction conversion table creation circuit 12. A corrected video signal VI3 is outputted by a switching circuit 14 when an inputted video signal VI has the value equal to or more than the gradation correction restriction parameter CP and the inputted video signal VI is outputted by the switching circuit 14 when the inputted video signal VI does not have the value of the gradation correction restriction parameter CP.;COPYRIGHT: (C)2005,JPO&NCIPI