Image forming apparatus and computer-readable recording medium storing program

An image forming apparatus comprising:

• a transfer body to be rotationally driven;
• an image forming unit that includes a plurality of developing units that are arranged in series for basic colors in a rotational driving direction of the transfer body and develop toner images of the basic colors based on input image data, and forms the overlapped color toner images on a surface of the transfer body in a state in which the toner images of the basic colors are aligned;
• a transferring unit that transfers the color toner images formed on the transfer body onto a sheet;
• and
• a controller that calculates a difference between color information of a read image obtained by allowing a reader to read the color toner images on the sheet and color information of the input image data, calculates a color change direction of the color toner images on the sheet with respect to a color of the input image data based on the difference between the color information, and refers to a table in which color change direction patterns are associated with portions determined to be recessed portions and determines a shape of a surface of the sheet based on information of the color change direction.