Patent ID: 7656558

Claim:
An image processing system that performs specified image processing on image data of a first resolution, and outputs dot data to form dots at a second resolution on a medium based on the results of the image processing, the image processing system comprising: encoding preparation unit that prepares a plurality of types in advance of encoding correlations to obtain the code values correlated to the results of multilevel halftoning for each pixel constituting the pixel group based on the representative gradation value that is the gradation value representing the pixel group consisting of a specified number of consecutive pixels; division determination unit that determines whether or not the sequentially fetched pixel groups from the image data are divided into a plurality of areas and processed based on the first resolution and the second resolution; representative gradation value setting unit that sets the representative gradation value for the entire pixel group when it is determined to process the pixel group without dividing, and that sets the respective representative gradation values for each area into which the pixel group is divided when it is determined to process the pixel group divided into a plurality of areas; encoding unit that, using the set representative gradation value, obtains the code value for each of the representative gradation values by referencing the encoding correlation allocated to the pixel group that is any one of the plurality of types of encoding correlations; decoding preparation unit that correlates the decoding correlation for obtaining the output dot arrangement representing the presence or absence of formation of dots for each pixel within the pixel group to the encoding correlation from the code that has a specific range of values and prepares a plurality of types in advance; decoding unit that references the decoding correlation corresponding to the encoding correlation allocated to the pixel group based on the obtained code value; and obtains the output dot arrangement corresponding to either the representative gradation value for the entire pixel group or the representative gradation values for each of the areas; dot arrangement setting unit that synthesizes the applicable obtained output dot arrangement if the obtained output dot arrangement corresponds to the entire pixel group, synthesizes the dot arrangement corresponding to each of the areas of the obtained output dot arrangement if it corresponds to each of the areas, and sets the output dot arrangement for each pixel constituting the pixel group; and output unit that outputs the set output dot arrangement as dot data.