“…They aim to locate predefined attributes, such as corners and boundaries [5,6], local extrema [7,8], or complex image regions [9][10][11][12]. The topdown methods are closely linked to particular applications such as object recognition [13][14][15], object detection [16], and image matching [17]. The top-down definition of saliency is used to measure the effectiveness of a feature for a particular task, i.e., the high saliency of a feature in [13] indicates the feature is discriminative for the given object category from the other categories, and the high saliency of a region in [17] means the region has a high probability to be correctly matched.…”