An image processing apparatus which generates, from first image data having a first resolution, second image data having a second resolution lower than the first resolution, comprises: a determination unit configured to determine a pixel of interest in the first image data based on the first resolution and the second resolution; a selection unit configured to select one of a plurality of filters in accordance with a position of the pixel of interest in the first image data that has been determined by the determination unit; and a generation unit configured to generate second image data having the second resolution by performing filter processing for a region including the pixel of interest by using the filter selected by the selection unit.