Image forming apparatus and method of correcting the characteristic of each body by printing reference pattern in the machine and reading the printed pattern again

Abstract

An image forming system which reads an image on a document includes a scanner section that serves as an input device for reading an image; a printer section that prints the read image as a hard copy; an operation panel for indicating a characteristic correction data preparation mode on an operation panel, and for inputting an operation start command. An image processing section includes an inner pattern generating section for generating a first reference gradation pattern, a characteristic correcting section that corrects the first reference gradation pattern P,by use of the first correction data f,and transmits a second reference gradation pattern P,to the printer section. A data selecting section transmits the first reference gradation pattern P,and the first correction data f,to the characteristic correcting section, and the printer section prints the transmitted second reference gradation pattern P,on a sheet as a hard copy. The scanner section reads the hard copy of the second reference gradation pattern P,, thereby obtaining a third reference gradation pattern P,. The characteristic correcting section synthesizes the second correction data f,with the first correction data f,to generate a third correction data f,. The characteristic correcting section corrects the gradation characteristic of the image information regarding the read image by use of the third correction data f