Image processing device and method, and image capturing device

An image processing method comprising:

• acquiring a first image and a second image that are captured through a single image-taking optical system and that have a parallax to each other after a pupil division by a pupil-division device;
• executing a parallax acquisition of acquiring a parallax between corresponding pixels of the acquired first image and second image;
• executing a first data transform of transforming, for each of a plurality of target pixels of processing of image data of the acquired first image and image data of the acquired second image, predetermined regions based on the target pixel into first frequency component data and second frequency component data, respectively;
• executing an operation processing of performing a multiplication process for each of the frequency component data of the acquired first image and second image by using a first frequency filter group and a second frequency filter group for respectively transforming the transformed first frequency component data and second frequency component data in a frequency space and for transforming the acquired first image and second image to a third image and a fourth image in which a parallax amount and a blur amount of the acquired first image and second image have been altered, the first frequency filter and the second frequency filter corresponding to the parallax of the target pixels acquired in the parallax acquisition;
• and
• executing a second data transform of transforming third frequency component data and fourth frequency component data respectively corresponding to the third image and the fourth image calculated in the operation processing into data on a real space and for respectively selecting pixels at positions corresponding to the target pixels as one pixel of the third image and one pixel of the fourth image, wherein
• the first data transform, the operation processing, and the second data transform are repeatedly executed for each pixel while shifting the positions of the target pixels.