1. A method being performed by a processor of a computing device, comprising: (a) reading a figure section of a design patent document comprising one or more figures; (b) converting each page of the figure section into a black-and-white image; (c) creating a first histogram based on information of black pixels and white pixels in the black-and-white image; (d) dividing the black-and-white image into a multiplicity of blocks which contain words or figures, according to the information of the white pixels in the first histogram; (e) selecting the blocks which have a height value greater than a predetermined height value; (f) creating a second histogram based on information of the black pixels and the white pixels in each selected block; (g) dividing the selected block into a multiplicity of areas which contain words or figures, according to the information of the white pixels in the second histogram; (h) selecting the areas which have a width value greater than a predetermined width value; and (i) displaying the selected areas on a display device.