Patent ID: 8851610

Claim:
An image processing device configured to transmit input image data to a liquid ejecting device including a recording head and a drive data generator, the recording head having a plurality of ejection ports for ejecting liquid onto a recording medium and having at least one liquid channel for supplying liquid to respective ones of the plurality of ejection ports, the drive data generator being configured to quantize the input image data to an N-valued data (N is a natural number satisfying N≧2) with a quantization process including a process of reducing a quantization error to generate drive data of the recording head, the image processing device comprising: a calculator configured to calculate a total value of tone values of all pixels belonging to each of a plurality of aggregations by allocating each pixel of M-valued image data (M is a natural number satisfying M>N) to one of the plurality of aggregations, each of a plurality of blocks being defined as either one of ejection-port groups including the plurality of ejection ports having a common liquid channel serving as a liquid supply source or one of a plurality of divided ejection-port groups that is obtained by dividing each of the ejection-port groups, each of the plurality of aggregations being defined as an aggregation of pixels of the M-valued image data corresponding to dots that are formed on the recording medium when liquid is ejected from the ejection ports belonging to one of the plurality of blocks during one of L ejection periods (L is a natural number satisfying L≧1), each of the L ejection periods corresponding to a number of divided ejection cycles that is obtained by dividing, by a plural number, a number of ejection cycles of the recording head required to record an image of the M-valued image data on one recording medium; a tone-value reducer configured to reduce tone values of at least part of the pixels belonging to the aggregation of the pixels of the M-valued image data; a transmitter configured to transmit the M-valued image data to the drive data generator of the liquid ejecting device, as the input image data; and a processor configured to perform: controlling the calculator to calculate the total value of the tone values of all the pixels belonging to each of the plurality of aggregations; controlling the tone-value reducer to, for an aggregation having the total value greater than or equal to a predetermined threshold, reduce the tone values of at least part of the pixels belonging to the aggregation so that the total value becomes less than the threshold, thereby adjusting the M-valued image data; and controlling the transmitter to transmit the M-valued image data to the drive data generator of the liquid ejecting device, as the input image data.