Image forming apparatus, image processing method, and medium

An image forming apparatus for interpreting data to generate intermediate data, the image forming apparatus comprising:

• a unit configured to determine whether or not there is a periodic drawing pattern in data;
• a unit configured to determine whether or not there is a reduction command in data;
• a unit configured to obtain, in a case where it is determined that there is a periodic drawing pattern in data and that there is a reduction command in data, a ratio between the number of pitches of the period of the drawing pattern and a reduction ratio included in the reduction command;
• a unit configured to determine whether or not the ratio and a value in a table loaded by the image forming apparatus coincide with each other;
• and
• a unit configured to reduce, in a case where it is determined that the ratio coincides with a value in the table, an image by dividing the image into cells and performing thinning processing in units of cells.