IMAGE SIGNAL PROCESSING APPARATUS, IMAGE SIGNAL PROCESSING METHOD, AND IMAGE CAPTURING APPARATUS

摘要

An image signal processing apparatus includes an image signal input unit; a gradation decrease evaluation device that evaluates a decrease in gradation within a certain area in image signals; a gradation loss evaluation device that evaluates a degree of gradation loss within a certain area in image signals; an image signal correction device that performs signal level correction processing on image signals and outputs the processing result; and an image signal correction control device that controls strength of correction by the image signal correction unit, using both the gradation decrease evaluated value which is output by the gradation decrease evaluation device and the gradation loss evaluated value which is output by the gradation loss evaluation unit.

主权项

1. An image signal processing apparatus comprising:
an image signal input device to which image signals are input; a gradation decrease evaluation device that calculates a gradation decrease evaluated value for evaluating a degree of gradation decrease with respect to an object which is included in the image signals from the image signal input unit; a gradation loss evaluation device that calculates a gradation loss evaluated value for evaluating a degree of gradation loss with respect to an object which is included in the image signals; an image signal correction device that performs signal level correction processing on the input image signals and outputs image signals whose signal levels have been corrected; and an image signal correction control device that controls correction strength of image signal correction processing that is executed by the image signal correction unit, using both the gradation decrease evaluated value which is output by the gradation decrease evaluation device and the gradation loss evaluated value which is output by the gradation loss evaluation unit, wherein the image signal correction control device performs control to decrease the correction strength, if having determined that the gradation decrease evaluated value is small, and to decrease the correction strength, if having determined that the gradation loss evaluated value is large.