1. An image forming apparatus comprising: a storage unit that stores pattern data on a transparent material, which corresponds to a type of visual effect that is applied to a recording medium by using the transparent material; a receiving unit that receives image data that is output to the recording medium by using colored material, additional data that indicates the type of visual effect, and arrangement information, including information that indicates an area of the image data relative to the recording medium; an arrangement-information processing unit that refers to the arrangement information to calculate a magnification for output of the image data; a selecting unit that selects the pattern data that corresponds to the type of visual effect, indicated by the additional data, from the storage unit; a magnification-change processing unit that reduces or enlarges a size of the selected pattern data in accordance with the calculated magnification; a first converting unit that converts the image data in accordance with the calculated magnification; and an image forming unit that forms an image on the recording medium by using the converted image data and the reduced-size or enlarged-size pattern data.