Image forming apparatus, method for deriving correction data, and non-transitory computer-readable storage medium

A method for deriving correction data, the method comprising:

• generating a correction chart, the correction chart including:
• a plurality of patches located in a first direction in which a recording medium is conveyed,
• the plurality of patches representing different densities from each other;
• and
• two marks located at different positions from each other in a second direction perpendicular to the first direction, wherein the two marks are located at positions determined based on a range of flare that affects reading of the plurality of patches on the recording medium,
• the generating including locating opposed end portions of the plurality of patches in the second direction outside the two marks in the second direction;
• and
• deriving correction data, based on read data provided by a reading device reading the correction chart formed on the recording medium, the read data including read data of an area of the plurality of patches existing inside the two marks in the second direction,
• the deriving including deriving the correction data, based on the read data of the area of the plurality of patches existing inside the two marks in the second direction.

A non-transitory, computer-readable storage medium storing computer-readable program code that causes a computer to perform a method for deriving correction data, the method comprising:

• generating a correction chart, the correction chart including:
• a plurality of patches located in a first direction in which a recording medium is conveyed,
• the plurality of patches representing different densities from each other;
• and
• two marks located at different positions from each other in a second direction perpendicular to the first direction, wherein the two marks are located at positions determined based on a range of flare that affects reading of the plurality of patches on the recording medium,
• the generating including locating opposed end portions of the plurality of patches in the second direction outside the two marks in the second direction;
• and
• deriving correction data, based on read data provided by a reading device reading the correction chart formed on the recording medium, the read data including read data of an area of the plurality of patches existing inside the two marks in the second direction,
• the deriving including deriving the correction data, based on the read data of the area of the plurality of patches existing inside the two marks in the second direction.