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 detects 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 a blank paper removing function is set to ON, and does not remove the image data corresponding to the manuscript detected as a blank paper by the blank paper detecting part when the blank paper removing function is set to OFF, and a faint character mode part that extracts a character from the image data and performs faint character adjustment for data of an extracted character; and the control part, when the blank paper removing function is set to ON and the blank paper is detected by the blank paper detecting part, does not make the image processing part perform image processing accompanied with the faint character adjustment by the faint character mode part, and when the blank paper removing function is set to OFF and the blank paper is detected by the blank paper detecting part, makes the image processing part perform image processing accompanied with the faint character adjustment by the faint character mode part the.