A method of analyzing an image, including a first stage and a second stage, wherein the first stage includes: inputting a pixel block, being a 2 x 2 and a two-dimensional array, composed of four pixels adjacent to one another in two dimensions as a single unit from data including a plurality of pixels for forming an image, together with an adjacent pixel group including six pixels that are adjacent to the pixel block and are adjoining an upper and a left edge of the pixel block and have already been labeled, the pixel block with the adjacent pixel group consisting of a vertical size of three lines of pixels; labeling, based on binarized pixels, all on-pixels or all off-pixels that are subject for grouping included in the pixel block with common identification information in a unit of the pixel block, the common identification information being an inherited identification when the adjacent pixel group includes inheritable identification information, and recording connecting information when the adjacent pixel group includes other inheritable identification information, or recording new identification information when the adjacent pixel group does not include inheritable identification information; and calculating block characteristic values of each pixel block in parallel with and independently of the labeling of each pixel block, the block characteristic values being calculated from the pixels in each pixel block, and the block characteristic values being stored in a unit of a pixel block, and wherein the second stage includes, calculating characteristic values of respective image elements composed of pixel blocks that have identification information connected by the connecting information, by calculating the block characteristic values stored in the unit of the pixel block referring to the identification information connected by the connecting information. inputting a pixel block, being a 2 x 2 and a two-dimensional array, composed of four pixels adjacent to one another in two dimensions as a single unit from data including a plurality of pixels for forming an image, together with an adjacent pixel group including six pixels that are adjacent to the pixel block and are adjoining an upper and a left edge of the pixel block and have already been labeled, the pixel block with the adjacent pixel group consisting of a vertical size of three lines of pixels; labeling, based on binarized pixels, all on-pixels or all off-pixels that are subject for grouping included in the pixel block with common identification information in a unit of the pixel block, the common identification information being an inherited identification when the adjacent pixel group includes inheritable identification information, and recording connecting information when the adjacent pixel group includes other inheritable identification information, or recording new identification information when the adjacent pixel group does not include inheritable identification information; and calculating block characteristic values of each pixel block in parallel with and independently of the labeling of each pixel block, the block characteristic values being calculated from the pixels in each pixel block, and the block characteristic values being stored in a unit of a pixel block, and wherein the second stage includes, calculating characteristic values of respective image elements composed of pixel blocks that have identification information connected by the connecting information, by calculating the block characteristic values stored in the unit of the pixel block referring to the identification information connected by the connecting information.