Image recording apparatus, image recording method, method for controlling the image recording apparatus, storage medium storing a program capable of being read by a computer, and image processing method

An image recording apparatus for performing recording using a dot pattern corresponding to each gradation value, based on image data representing each pixel with one of N gradation values, said apparatus comprising:

• an input unit for inputting image data including gradation-value information and position information relating to each pixel;
• a dot-pattern-table storage unit for storing N dot-pattern tables, each having a plurality of different dot patterns, corresponding to respective ones of the N gradation values;
• first selection means for selecting one dot-pattern table from said dot-pattern-table storage unit, based on gradation-value information indicated by each pixel of the image data input by said input unit;
• second selection means for selecting one dot pattern from the dot-pattern table selected by said first selection means, based on position information indicated by the pixel;
• and
• recording control means for controlling a recording head so as to record an ink dot based on the dot pattern selected by said second selection means on a recording medium.

A storage medium, capable of being read by a computer, storing program codes for executing recording control processing for an image recording apparatus for performing recording using a dot pattern corresponding to each gradation value, based on image data representing each pixel with one of N gradation values, said program codes comprising:

• (a) a code of an input step for inputting image data including gradation-value information and position information relating to each pixel;
• (b) a code of a first selection step for selecting one dot-pattern table based on gradation-value information indicated by each pixel of the image data input in said input step, from among N dot-pattern tables, each having a plurality of different dot patterns, corresponding to respective ones of the N gradation values;
• (c) a code of a second selection step for selecting one dot pattern based on position information indicated by the pixel, from the dot-pattern table selected in said first selection step;
• and
• (d) a code of a recording step for recording an ink dot based on the dot pattern selected in said second selection step on a recording medium using a recording head.

An image processing method for outputting a dot pattern corresponding to each gradation value, based on image data representing each pixel with one of N gradation values, said method comprising the steps of:

• an input step for inputting image data including gradation-value information and position information relating to each pixel;
• a first selection step for selecting one dot-pattern table based on gradation-value information indicated by each pixel of the image data input in said input step, from among N dot-pattern tables, each having a plurality of different dot patterns, corresponding to respective ones of the N gradation values;
• a second selection step for selecting one dot pattern based on position information indicated by the pixel, from the dot-pattern table selected in said first selection step;
• and
• an output step for outputting the dot pattern selected in said second selection step.

An image recording apparatus for outputting dot patterns corresponding to respective gradation values and recording the output dot patterns using recording materials having a plurality of colors by a recording unit, based on image data representing each pixel with one of N gradation values, said apparatus comprising:

• an input unit for inputting image data including position information, gradation-value information and color information relating to each pixel;
• a dot-pattern-table storage unit for storing N dot-pattern tables, each having a plurality of different dot patterns, corresponding to respective ones of the N gradation values, for each color of the recording materials;
• and
• an output unit for outputting one dot pattern from said dot-pattern-table storage unit, based on position information, gradation-value information and color information indicated by each pixel of the image data input by said input unit,
• wherein a size of a dot-pattern table corresponding to at least one specific color from among the dot-pattern tables stored for each of the plurality of colors is smaller than sizes of dot-pattern tables corresponding to colors other than the specific color.

An image recording method for outputting dot patterns corresponding to respective gradation values and recording the output dot patterns using recording materials having a plurality of colors by a recording unit, based on image data representing each pixel with one of N (N is an integer equal to or larger than 2) gradation values, said method comprising the steps of:

• an input step for inputting image data including position information, gradation-value information and color information relating to each pixel;
• an output step for outputting one dot pattern based on position information, gradation-value information and color information indicated by each pixel of the image data input in said input step, from a dot-pattern-table storage unit for storing N dot patterns, each having a plurality of different dot patterns, corresponding to respective ones of the N gradation values, for each color of the recording materials;
• and
• a recording step for recording the dot pattern output in said output step by the recording unit,
• wherein a size of a dot-pattern table corresponding to at least one specific color from among the dot-pattern tables stored for each of the plurality of colors is smaller than sizes of dot-pattern tables corresponding to colors other than the specific color.

An image recording method for performing recording using a dot pattern corresponding to each gradation value, based on image data representing each pixel with a gradation value, said method comprising the steps of:

• a selection step for selecting one dot pattern based on gradation value information of the pixel on the image data and position information of the pixel, from a dot pattern table having a plurality of different dot patterns associated with gradation value and pixel position;
• and
• a recording step for recording an ink dot based on the dot pattern selected in said selection step on a recording medium using a recording head,
• wherein the dot pattern table has a plurality of different dot patterns, each having the same dot number and a different dot arrangement, corresponding to the same gradation value, and
• wherein the dot pattern table is repeatedly used at each of a plurality of pixels in a first direction substantially corresponding to a direction of arrangement of nozzles of the recording head.

An image recording method for performing recording using a dot pattern corresponding to each gradation value, based on image data representing each pixel with a gradation value, said method comprising the steps of:

• a selection step for selecting one dot pattern based on gradation value information of the pixel on the image data and position information of the pixel, from a dot pattern table having a plurality of different dot patterns associated with gradation value and pixel position;
• and
• a recording step for recording an ink dot based on the dot pattern selected in said selection step on a recording medium using a recording head,
• wherein the dot pattern table has a plurality of different dot patterns, each having the same dot number and a different dot arrangement, corresponding to the same gradation value, and
• wherein the dot pattern table is repeatedly used at each of a plurality of pixels in a second direction substantially orthogonal to a direction of arrangement of nozzles of the recoding head.

An image recording method for performing recording using a dot pattern corresponding to each gradation value, based on image data representing each pixel with respective gradation values, said method comprising the steps of:

• a selection step for selecting one dot pattern based on gradation value information of the pixel on the image data and position information of the pixel, from a dot pattern table having a plurality of different dot patterns associated with gradation value and pixel position;
• and
• a recording step for recording an ink dot based on the dot pattern selected in said selection step on a recording medium using a recording head,
• wherein the dot pattern table has a plurality of different dot patterns, each having the same dot number and a different dot arrangement, corresponding to the same gradation value, and
• wherein the dot pattern table is repeatedly used at each of a plurality of pixels in a first direction substantially corresponding to a direction of arrangement of nozzles of the recording head and is repeatedly used at each of a plurality of pixels in a second direction orthogonal to the first direction.