Patent ID: 8564862

Claim:
An image signal processing apparatus comprising: a control unit configured to determine a gradation correction characteristic representing a conversion characteristic for correcting brightness of an input frame; a separation unit configured to separate the gradation correction characteristic determined by the control unit into a representative gradation correction value representing an amount of correction for a representative value of a main subject and a remaining gradation correction characteristic obtained by removing the representative gradation correction value from the gradation correction characteristic; a gain processing unit configured to uniformly apply the representative gradation correction value separated by the separation unit to the frame as a gain; a noise reduction processing unit configured to perform noise reduction processing on the frame to which the representative gradation correction value is applied by the gain processing unit; and a gradation correction processing unit configured to perform gradation correction processing on the frame for which the noise reduction processing has been performed by the noise reduction processing unit using the remaining gradation correction characteristic separated by the separation unit.