Image forming apparatus and recording medium suitable for image forming process

A non-transitory computer-readable recording medium for storing an image forming program executable on a computer for controlling an image forming apparatus, and the computer functions as, when executing the image forming program:

• an image-processing unit for performing image processing on first printing data;
• a printer unit for performing printing based on second printing data stored in a storage device of the image forming apparatus, the second printing data having undergone the image processing on the first printing data by the image-processing unit;
• and
• a system-control unit that controls a moving of the image-forming unit between a printing pre-start position and a printing start position,
• wherein the image-processing unit has:
• a first data-processing unit for converting the first printing data into bitmap third printing data;
• a second data-processing unit for determining whether the bitmap third printing data has a periodicity of an image or not;
• a color-conversion-processing unit for, by a speculative process in parallel with a process by the second data processing unit, generating fourth printing data that has undergone a color conversion process corresponding to a printer printing on the third printing data;
• a screen-processing unit for, by the speculative process in parallel with the process by the second data processing unit, performing an AM screen process on the fourth printing data;
• and
• a data-output unit for outputting the printing data screen-processed by the screen-processing unit to the printer unit as the second printing data,
• wherein the screen-processing unit:
• a) in the case where it is determined by the second data-processing unit that the bitmap third printing data does not have the periodicity of the image, sends printing data screen-processed by the AM screen process to the data-output unit;
• and
• b) in the case where it is determined by the second data-processing unit that the bitmap third printing data has the periodicity of the image, i) instructs the color-conversion-processing unit to perform a re-color conversion process corresponding to a copy printing on the third printing data, ii) discards the printing data screen-processed by the AM screen process, and iii) performs an FM screen process on the forth printing data on which the re-color conversion process corresponding to the copy printing has been performed,
• wherein the color-conversion-processing unit determines a printing color based on the fourth printing data that has undergone the color conversion process corresponding to the printer printing by the color-conversion processing unit, and
• wherein the system-control unit:
• a) controls the moving of the image-forming unit corresponding to the printing color from the printing pre-start position to the printing start position based on the fourth printing data that has undergone the color conversion process corresponding to the printer printing by the color-conversion-processing unit;
• and
• b) does not control the moving of the image-forming unit corresponding the printing color based on the fourth printing data that has undergone the re-color conversion process corresponding to the copy printing by the color-conversion-processing unit.