1. An image processing apparatus comprising: a blank-area identifying unit that identifies a blank area having a size exceeding a predetermined size, from a non-specifying-mark image portion of a recording area image of a recording area that includes individual images and a specifying mark specifying an area containing images among the individual images, the non-specifying-mark image portion being an image portion of the recording area image other than a specifying-mark image that represents the specifying mark, the recording area image being represented by image information; and a concealing unit that conceals a divided area specified by the specifying-mark image, among divided areas obtained by dividing a non-blank area by a gap having a width equal to or larger than a threshold in a specific direction, among gaps between the individual images arranged in the specific direction in the non-blank area, the non-blank area being an area of the non-specifying-mark image portion of the recording area image other than the blank area identified by the blank-area identifying unit, wherein the concealing unit conceals the divided area in response to the specifying-mark image extending completely across the divided area in the specific direction, among the divided areas obtained by dividing the non-blank area by the gap, and does not conceal remaining divided areas of the divided areas in response to the specifying-mark image not extending completely across the remaining divided areas in the specific direction, and wherein the predetermined size is the size of the largest individual image among the individual images included in the recording area image.