1. A method implemented at least partially by a processor, the method comprising: receiving an input image that includes a salient object; segmenting the input image into multiple regions; calculating a saliency value for each of the segmented regions based on scale image levels; constructing saliency maps based at least in part on the calculated saliency value for each of the segmented regions, the saliency maps to be constructed for the scale image levels; constructing a total saliency map by combining the saliency maps constructed for the scale image levels; connecting a set of line segments that are computed from the input image and utilizing the total saliency map to define a shape prior that has a defined boundary; and extracting the salient object from the total saliency map and the shape prior.