1. An image processing apparatus including a document type automatic discrimination section that, based upon input image data read from a document, automatically discriminates a document type of the document wherein the document type automatic discrimination section, based upon plural types of parameters that are obtained from plural types of characteristics extracted from the input image data and which parameters are used for discriminating a document type, discriminates a specific inkjet printed image whose output image data would not reach a standard level, if a process for a halftone reproduction region or a process for a continuous tone region were to be carried out on the input image data.