Patent ID: 7016086
Filing Date: 2006-03-21
Classification: H04N

Abstract:
1. An image forming apparatus comprising: a scanner section which reads a document in a main scanning direction and in a sub-scanning direction to provide image data indicating a density of each pixel within a document image for each image line in the main scanning direction; a storing section which stores the image data provided from the scanner section in a memory; a setting section which sets the number of image lines for calculation used for calculation of reference values for density correction; a density histogram creating section which takes in the image data provided from the scanner for each image line and creates a density histogram of the document image on the basis of image data corresponding to the number of image lines for calculation set by the setting section; a correction reference value calculating section which calculates a set of correction reference values for pixel density correction using the density histogram created in the density histogram creating section; a pixel density correcting section which reads out the image data stored in the memory and performs correction of a pixel density indicated by the image data on all the read image data using the set of correction reference values calculated in the correction reference value calculating section; and an image forming section which forms an image from the pixel density corrected in the pixel density correcting section, wherein the correction reference value calculating section comprises a detecting section which detects two representative densities (D the pixel density correcting section corrects the input pixel density according to the following equation: where D