Image processing apparatus, control method of image processing apparatus, image forming apparatus, and storage medium

An image forming apparatus comprising:

• a photosensitive member;
• an image processing apparatus configured to correct input image data;
• an exposure unit configured to expose a surface of the photosensitive member by scanning a surface of the photosensitive member with a light beam based on the image data corrected by the image processing apparatus;
• and
• a developing unit configured to develop an electrostatic latent image formed on the surface of the photosensitive member by exposure of the exposure unit so as to form an image to be transferred to a printing material on the surface of the photosensitive member,
• wherein the image processing apparatus comprises:
• a storage unit configured to store correction values for respective pixels in a main scanning direction of a scanning line, the correction values being required to correct a misregistration of an image to be formed by a light beam, which is caused by deviation of the scanning line of a light beam used to scan a surface of the photosensitive member from an ideal position on the surface of the photosensitive member;
• a determination unit configured to determine whether or not image data to be corrected using the correction values includes a specific pattern;
• a modification unit configured to modify, when the determination unit determines that the image data includes the specific pattern, correction values corresponding to pixels including the specific pattern, of the correction values stored in the storage unit using any of a plurality of different predetermined modification values;
• and
• a correction unit configured to correct the image data for respective pixels using the correction values stored in the storage unit or the correction values modified by the modification unit.

A control method of an image processing apparatus, which comprises a storage unit configured to store correction values for respective pixels in a main scanning direction of a scanning line, the correction values being required to correct a misregistration of an image formed by a light beam, which is caused by deviation of the scanning line of a light beam used to scan a surface of a photosensitive member from an ideal position on the surface of the photosensitive member, the method comprising steps of:

• determining whether or not image data to be corrected using the correction values includes a specific pattern;
• modifying, when it is determined that the image data includes the specific pattern, correction values corresponding to pixels including the specific pattern, of the correction values stored in the storage unit using any of a plurality of different predetermined modification values;
• and
• correcting the image data for respective pixels using the correction values stored in the storage unit or the modified correction values.