HOGs are built from cells that are combined in overlapping blocks. It is, therefore, difficult to visualize this descriptor. Nevertheless, they are often represented by displaying the histograms associated with each cell. In this case, instead of aligning the orientation bins in a regular bar graph, a histogram of orientation can be more intuitively drawn in a star-shape, where each line has the orientation associated to bin that it represents and the length of the line is proportional to that bin count. These HOG representations can then be displayed over an image, as follows:
Each cell HOG representation can be produced ...
