A Hierarchical Probabilistic Model for Rapid Object Categorization in Natural Scenes
The upper panels in (A) and (B) are examples of the ICs of images of animals and cars at a finer scale respectively. Each frequent structure for the 5 animals and cars was the average of patches that shared the same dominant orientation structure at two spatial scales. The numbers indicate the locations of the structures in the animals and cars. The coarse structural description was for image patches of 48×48 pixels and the fine structural description was for the 3×3 blocks of the same patches (each block had 16×16 pixels). Most of the structures at the two spatial scales are similar except some fine details, e.g., the No. 4 and 6 structures of the zebra. The structures at the second scale (3×3 blocks) contain more details than the first scale (48×48 pixels).