An image processing apparatus forming an image with color toners used for full color printing and a particular toner is provided. The apparatus comprises a storage storing image data and attribute information indicating an attribute of each pixel in the data; a compression component compressing the information; a change component changing attribute information except particular toner information for forming an image with the particular toner of the attribute information, so that a data amount of the compressed attribute information does not exceed the storage capacity, when a data amount of the compressed attribute information exceeds the storage capacity; a component storing the attribute information changed by the change component into the storage; and a component forming a full color image and a particular toner image by image processing using the attribute information in the storage for the image data in the storage.