Image processing apparatus that performs tone correction and edge enhancement, control method therefor, and storage medium

摘要

An image processing apparatus which enables natural edge enchantment suited to a frequency band of a subject even when performing local contrast correction in combination with edge enhancement. A local contrast correction unit multiplies a signal of a target pixel in image data by a gain based on values obtained by reflecting signals of pixels around the target pixels. For signals of the target pixel output from the local contrast correction unit, a gamma conversion unit performs gamma conversion based on the signal of the target pixel. An edge signal is extracted from the image data and multiplied by a gain based on a signal output from the local contrast correction unit. The edge signal is added to a signal output from the gamma conversion unit.

主权项

1. An image processing apparatus comprising:
a first correction unit configured to multiply a signal of a target pixel in image data by a first gain based on values obtained by reflecting signals of pixels around the target pixel; a gamma conversion unit configured to, for a signal of the target pixel output from said first correction unit, carry out gamma conversion based on the signal of the target pixel; an edge extraction unit configured to extract an edge signal from the image data; a second correction unit configured to multiply the edge signal corresponding to the target pixel by a second gain to generate a corrected edge signal; and an adding unit configured to add the corrected edge signal output from said second correction unit to a signal output from said gamma conversion unit, wherein the second gain is based on the signal of the target pixel in image data that has been multiplied by the first gain, and the edge signal is extracted from image data that has not been multiplied by the first gain.