Patent ID: 6061144
Filing Date: 2000-05-09
Classification: H04N

Abstract:
A color image forming apparatus, comprising:original document reading means for reading an image of an original document and for generating image signals respectively representing color elements representing said image of said original document;image signal processing means for processing said image signals output from said original document reading means and for separating said image signals into image signals for a letter image and image signals for a photo image;image recording means for converting said image signals into a visual form of a color image on a recording medium;interface means for receiving an instruction entered by an operator and for informing said operator of a state of said color image forming apparatus;storing means for storing data representing a reference image including a plurality of color gray scales, each color gray scale including a plurality of blocks, each block having an image density stepwise different from an image density of other blocks, for each color element for said letter image and said photo image, and for pre-storing, prior to the original document reading means reading the reference image, at least one data table for gamma data; andgamma selection control means for controlling said image recording means to record said reference image stored in said storing means on a recording medium upon receiving a recording instruction through said interface means, for controlling said original document reading means to read said reference image recorded on said recording medium, for detecting an input of a change instruction for changing said gamma data through said interface means, for changing said gamma data, and for analyzing a difference of image density of each of said color elements between said reference image stored in said storing means and said reference image recorded on said recording medium.