Image forming apparatus and image forming method with gamma correction

An image forming method that can form an image at a first resolution and a second resolution, the method comprising:

• printing an image for correction, which image for correction includes a first test pattern on a medium for gamma correction printed at a third resolution higher than the first resolution and a second test pattern for the gamma correction printed at the third resolution, in a print unit configured to form an image on the medium at a resolution selected from a plurality of resolutions including the first resolution and the second resolution higher than the first resolution;
• reading the image for correction printed on the medium;
• and
• obtaining first correction information to be used for printing at the first resolution and second correction information to be used for printing at the second resolution, based on the reading of the image for correction read on the medium, wherein obtaining the first correction information and the second correction information comprises using a first threshold with a first threshold matrix for the first resolution and using a second threshold with a second threshold matrix for the second resolution.

An image forming apparatus comprising:

• a print unit configured to form an image on a medium at a resolution selected from a plurality of resolutions including a first resolution and a second resolution higher than the first resolution;
• a print control unit configured to control the print unit to print on the medium an image for correction, which image for correction includes a first test pattern for gamma correction printed at a third resolution higher than the first resolution and a second test pattern for the gamma correction printed at the third resolution;
• a reading unit configured to read the image for correction printed on the medium;
• and
• a processing unit configured to obtain first correction information to be used for printing at the first resolution and second correction information to be used for printing at the second resolution, based on the reading, by the reading unit, of the image for correction on the medium, wherein the third resolution is an integer multiple of the first resolution and is the integer multiple of the second resolution.