1. An image processing apparatus, comprising: a processor configured to perform subject area detection processing a plurality of times on an input image to detect respective subject areas on a plurality of processes performed on the input image with different resolutions including a lower resolution and a higher resolution; determine whether an overlap exists between each pair of the respective subject areas with the different resolutions respectively by determining an overlap respectively between a first subject area of a certain object in the input image with the lower resolution and a second subject area of the certain object in the input image with the higher resolution after making each pair of the respective subject areas with the different resolutions equal in size; determine a final subject area for the input image based on a number of the pair for which the overlap is determined to exist; and perform a control related with imaging based on the determined final subject area of the input image.