There are provided a foreground region extraction program, a foreground region extraction apparatus, and a foreground region extraction method capable of clipping an object region (foreground region) at high speed.
An arrangement is as follows: Foreground pixels designated by a user and background pixels designated thereby are each set as a reference pixel to identify, from among a plurality of divided color spaces created by a three-dimensional color space being divided, the divided color space to which each of the reference pixels belongs, as a reference divided color space. Color distance calculation processing to calculate a color distance in the color space between each reference pixel and an adjacent pixel adjacent thereto is performed, and belonging judgment processing to judge whether each of the adjacent pixels belongs to each of the reference divided color spaces is performed, and then, cost calculation processing to calculate a cost of each adjacent pixel is performed, based on the color distance calculated for each of the adjacent pixels, and weights based on whether to belong to the reference divided color space judged for each of the adjacent pixels. Further determination processing to determine the adjacent pixel having the lowest calculated cost as a foreground pixel or background pixel is performed, and a foreground region is extracted from the image by using the determined adjacent pixel as a reference pixel to repeatedly perform the color distance calculation processing, the belonging judgment processing, the cost calculation processing, and the determination processing.