1. An image forming apparatus comprising: a scanner part that reads a manuscript; an image processing part that performs image processing for image data of a read manuscript; a blank paper detecting part that detects whether the read manuscript is a blank paper; and a control part that controls reading operation by the scanner part, image processing by the image processing part, and detecting operation by the blank paper detecting part, wherein the image processing part has a blank paper removing part that removes the image data corresponding to the manuscript detected as a blank paper by the blank paper detecting part when function is set to ON, and a faint character mode part that extract a character from the image data and perform faint character adjustment for data of an extracted character; and the control part, when the blank paper removing part is set to OFF and the blank paper is detected by the blank paper detecting part, makes perform image processing accompanied with the faint character adjustment by the faint character mode part to the image processing part.