1. A method implemented by a computing device, the method comprising: determining boundary regions of an image that depicts a scene, each of the boundary regions comprising less than an entirety of the image; computing intermediate saliency maps of each of the boundary regions, the intermediate saliency maps representing visual saliency of portions of the scene that are captured in the boundary regions, the intermediate saliency maps computed based on the visual saliency of the portions of the scene captured in the boundary regions being background of the scene; and combining the intermediate saliency maps to generate a base saliency map of the image, the intermediate saliency maps being combined to suppress an effect of one or more foreground objects on the base saliency map, the one or more foreground objects that have the effect suppressed occupying a majority of one of the boundary regions.