There is provided a color conversion processing method and the like, which are capable of performing a data processing for images with a common processing system independently of a printer and also capable of performing a flexible alteration of the processing method, even if it is concerned with the printer restricted in the above-mentioned matter. In the event that there is a restriction on a total value of the respective values of CMYK on one pixel for instance, for a respective printer, image data is converted into image data suitable for the printer involved in the restriction. Processing in a printer conversion processing section, which is hitherto performed by the hardware operating processing, is implemented in form of a profile (referred to as a printer processing conversion profile). The printing profile and the printer profile are combined with the printer processing conversion profile to create a combined profile. The color conversion processing is performed in accordance with the combined profile.

An image forming apparatus includes a receiving device which receives an image and first printing conditions for printing the image from a terminal via a network, a generating device which generates second printing conditions on the basis of the first printing conditions and settings of the image forming apparatus, a comparing device which compares the first and second printing conditions to determine whether or not one or more discrepancies occur between them, a first storage device which stores a table which stores discrepancies to be determined to occur and solutions each of which corresponds to each of the discrepancies, a first setting device which automatically sets, by using the table, a solution among the solutions for each of the discrepancies determined to occur, and a printing device which prints the image on printing conditions in which the one or more discrepancies are solved by the set solution.

An image processing system and method include allowing an output device to output patch-data items of plural multi-order colors represented by a first color space, measuring the color values, in an absolute color space, of the output patch-data items, calculating reference values by converting the plural multi-order colors represented by the first color space based on a first color conversion table containing correspondence between the first color space and the absolute color space, calculating distances between the color values measured by the color measuring means and the reference values, which correspond thereto, and correcting, based on the calculated distances, a second color conversion table containing correspondence between the absolute color space and an output color space.

A color converting device converts input CMYK data into output color data in a predetermined different format. The color converting device comprises a contrast emphasizing unit emphasizing a contrast of the output color data corresponding to the CMYK data representing a black-character color more than a contrast of the output color data corresponding to the CMYK data representing a non-black-character color.

A method for correcting digitized image data in the prepress stage when using printing presses having a device-independent color profile in the main printing stage, having the following method steps: colorimetric measurement of a reference sheet and production of an image file in a device-independent color space, conversion of an image file belonging to the reference sheet in a device-dependent color space into a further image file in a device-independent color space using the device-independent color profile belonging to the printing press to be used, comparison of the two device-independent image files. performing alterations on the device-dependent image file associated with the reference sheet or alteration of the printing process in the selected printing press if tolerance limits are exceeded.