1. A region-of-interest detection apparatus comprising:a memory; and
a processor in communication with the memory, the processor configured to provide:
a segmentation unit configured to segment an input image into a plurality of partial regions;
a background region setting unit configured to set a background region in the input image;
an overlap region setting unit configured to set a plurality of overlap regions each corresponding to a region in which one of the partial regions and the background region overlap each other, and calculate a region feature amount of each of the overlap regions;
a foreground level calculation unit configured to calculate a foreground level indicating a possibility of a foreground based on the region feature amount of each of the overlap regions and a pixel feature amount of each of a plurality of pixel positions in the input image, the foreground level being calculated for each of the plurality of pixel positions;
a saliency calculation unit configured to, based on the feature amount of each of the plurality of pixel positions and a feature amount of a portion around each of the plurality of the pixel positions, calculate a saliency indicating a degree of saliency of each of the plurality of pixel positions; and
a detection unit configured to detect a region of interest based on the foreground level and the saliency of the position.