1. An image processing apparatus comprising: an image acquisition unit that acquires an input image that is to be subjected to processing; a foreground map generation unit that generates a foreground map, which indicates a foreground region and a background region in the input image, based on the input image; a learning sample extraction unit that extracts data of a positive learning sample from the foreground region in the input image and extracts data of a negative learning sample from the background region in the input image, based on the foreground map; a classifier learning unit that performs learning of a plurality of classifiers using the positive and negative learning samples extracted from the input image; a strong classifier generation unit that generates a strong classifier by combining the plurality of learned classifiers; and a saliency map generation unit that generates a final saliency map of the input image using the strong classifier.