Image processing apparatus, image processing method, and non-transitory computer-readable storage medium

An image processing method comprising:

• calculating ambient light based on an input image;
• generating a dark channel image having a minimum value of a color channel of a local region in the input image as a pixel value based on the input image and the ambient light, and generate a transmittance distribution of atmosphere based on the dark channel image;
• performing processing of shaping the transmittance distribution a plurality of times;
• and
• generating a corrected image in which contrast of the input image is corrected based on a shaped transmittance distribution and the ambient light.

A non-transitory computer-readable storage medium storing a computer program for causing a computer to function as:

• a calculation unit configured to calculate ambient light based on an input image;
• a first generation unit configured to generate a dark channel image having a minimum value of a color channel of a local region in the input image as a pixel value based on the input image and the ambient light, and generate a transmittance distribution of atmosphere based on the dark channel image;
• a shaping unit configured to perform processing of shaping the transmittance distribution a plurality of times;
• and
• a second generation unit configured to generate a corrected image in which contrast of the input image is corrected based on a shaped transmittance distribution shaped by the shaping unit and the ambient light.