An image processing apparatus processes a first image signal including pixel signals, the first image signal having a picture portion in which a subject is shown and having a blank portion surrounding the picture portion. The apparatus includes: a blank detection unit configured to set similar frames different in size from one another within a display area of a screen representing the first image signal, in a stepwise manner from an outer periphery, and to detect the blank portion based on whether or not a part of the pixel signals belonging to a region outside each of the similar frames has the uniform color or brightness; a region-of-interest setting unit configured to set an initial region-of-interest corresponding to the picture portion in the first image signal, based on the blank portion; and a region-of-interest image generation unit configured to generate a region-of-interest image signal representing the initial region-of-interest.