Patent ID: 8320024

Claim:
An image forming apparatus comprising: a skew correction unit that performs skew correction on image data by dividing pixels that belong to one line in a main-scanning direction of the image data into pixel blocks at least one shift position and shifting a pixel block of the pixel blocks in a sub-scanning direction against a direction of skew; a noise determining unit that determines whether a pixel of interest that is on the shift position is a noise-inducing pixel, the pixel of interest being each pixel on the shift position, the noise-inducing pixel being a pixel that leads to a local color density change because of a change in relationship with an adjacent pixel of the noise-inducing pixel; a selecting unit that selects, when the pixel of interest is determined as being the noise-inducing pixel, any one of the pixel of interest and a pixel in vicinity of the pixel of interest as a correction target pixel on which color density correction is to be performed; a first correcting unit that performs the color density correction on density-not-yet-corrected image data of the correction target pixel to acquire density-corrected image data; and a second correcting unit that corrects an output point in time at which the density-corrected image data is to be output, the output point in time falling within a pixel period during which the density-corrected image data of the correction target pixel can be output, such that the image data of the correction target pixel is output at an output position that is displaced from a center position corresponding to a center point in time of the pixel period in any one of a direction toward the shift position and a direction away from the shift position, wherein: when a color density of the density-corrected image data is determined to decrease as compared to a color density of the density-not-yet-corrected image data, the second correcting unit corrects the output point in time such that the output position is displaced toward the shift position, and when the color density of the density-corrected image data is determined to increase as compared to the color density of the density-not-yet-corrected image data, the second correcting unit corrects the output point in time such that the output position is displaced away from the shift position.