Image forming apparatus, method of generating image data therefor and storage medium

A method of generating image data for an image forming apparatus having a first printing mode and a second printing mode whose development parameters are different from those of the first printing mode and performing electrophotographic printing, the method comprising the steps of:

• performing scan line changing processing to shift an image in units of pixels in a sub scanning direction at a predetermined scan line changing point in a main scanning direction in accordance with characteristics of a laser scan line;
• and
• correcting a tone level value of a pixel of interest in an image after the scan line changing processing by referring to a tone level value of an adjacent pixel neighboring the pixel of interest in a sub scanning direction, wherein
• at the correction step:
• the correction is performed by using a correction coefficient set in which a group of a correction coefficient to be applied to the pixel of interest and a correction coefficient to be applied to at least one of the adjacent pixels with respect to the pixel of interest in a sub scanning direction is associated with a variable specifying a relative position in a main scanning direction with the scan line changing point being taken as a start point;
• and
• different correction coefficient set is used between a case where printing is performed in the first printing mode and a case where printing is performed in the second printing mode in the image forming apparatus.

A non-transitory computer readable storage medium storing a program for causing a computer to perform a method of generating image data for an image forming apparatus having a first printing mode and a second printing mode whose development parameters are different from those of the first printing mode and performing electrophotographic printing, the method comprising the steps of:

• performing scan line changing processing to shift an image in units of pixels in a sub scanning direction at a predetermined scan line changing point in a main scanning direction in accordance with characteristics of a laser scan line;
• and
• correcting a tone level value of a pixel of interest in an image after the scan line changing processing by referring to a tone level value of an adjacent pixel neighboring the pixel of interest in a sub scanning direction, wherein
• at the correction step:
• the correction is performed by using a correction coefficient set in which a group of a correction coefficient to be applied to the pixel of interest and a correction coefficient to be applied to at least one of adjacent pixels with respect to the pixel of interest in a sub scanning direction is associated with a variable specifying a relative position in a main scanning direction with the scan line changing point being taken as a start point;
• and
• different correction coefficient set is used between a case where printing is performed in the first printing mode and a case where printing is performed in the second printing mode in the image forming apparatus.