Ink jet printing apparatus and image processing apparatus

An image processing apparatus that performs processing on multivalued image data corresponding to a unit region for printing an image in the unit region including a plurality of pixel regions on a printing medium by a plurality of scans of a an eject port column in which a plurality of eject ports for ejecting ink are arrayed in a predetermined direction with respect to the printing medium, wherein the plurality of eject ports ejects ink to each of the plurality of pixel regions on the printing medium in accordance with dot printing data corresponding to each of the plurality of scans, and by conveying the printing medium between the plurality of scans, the image processing apparatus comprising:

• a first acquisition unit configured to acquire information on a density of an image that is printed in the pixel region;
• a second acquisition unit configured to acquire N (≧3)-valued quantized data corresponding to the pixel region based on the image data;
• a third acquisition unit configured to acquire a plurality of dot arrangement pattern groups including at least a first dot arrangement pattern group including a plurality of first dot arrangement patterns in which an arrangement of dots is determined so that the number and position of dots that are printed within the pixel region are different in accordance with a value of the N-valued quantized data and a second dot arrangement pattern group including a plurality of second dot arrangement patterns in which an arrangement of dots is determined so that the number and position of dots that are printed within the pixel region are different in accordance with a value of the N-valued quantized data;
• a setting unit configured to set one dot arrangement pattern group from the plurality of dot arrangement pattern groups acquired by the third acquisition unit in accordance with the positions of the plurality of pixel regions within the unit region;
• and
• a generation unit configured to generate the dot printing data based on the N-valued quantized data acquired by the second acquisition unit and the dot arrangement pattern group set by the setting unit,
• wherein the number of dots that are printed within the pixel region determined by the second dot arrangement pattern corresponding to the N-valued quantized data having a predetermined value is smaller than the number of dots that are printed within the pixel region determined by the first dot arrangement pattern corresponding to the N-valued quantized data having the predetermined value, and
• the setting unit sets the dot arrangement pattern group so that:
• (i) the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at a first position, that is included in an end part region of the unit region in the predetermined direction corresponding to an end part of the eject port column in the predetermined direction, in a case where the density of the image indicated by the information acquired by the first acquisition unit is a first value is smaller than the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at the first position in a case where the density of the image indicated by the information acquired by the first acquisition unit is a second value lower than the first value;
• (ii) the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at a second position, that is included in the end part region and is closer to an end of the unit region than the first position in the predetermined direction, in a case where the density of the image indicated by the information acquired by the first acquisition unit is the first value is smaller than the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at the second position in a case where the density of the image indicated by the information acquired by the first acquisition unit is the second value;
• and
• (iii) the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at the second position in a case where the density of the image indicated by the information acquired by the first acquisition unit is the second value is larger than the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at the first position in a case where the density of the image indicated by the information acquired by the first acquisition unit is the second value, and
• the number of the first dot arrangement pattern groups determined for the plurality of pixel regions located at the second position in a case where the density of the image indicated by the information acquired by the first acquisition unit is the second value is smaller than the number of the first dot arrangement pattern groups determined for the plurality of pixel regions located at the first position in a case where the density of the image indicated by the information acquired by the first acquisition unit is the second value.

An image processing apparatus that performs processing on multivalued image data corresponding to a unit region for printing an image in the unit region including a plurality of pixel regions on a printing medium by a plurality of scans of a an eject port column in which a plurality of eject ports for ejecting ink are arrayed in a predetermined direction with respect to the printing medium, wherein the plurality of eject ports ejects ink to each of the plurality of pixel regions on the printing medium in accordance with dot printing data corresponding to each of the plurality of scans, and by conveying the printing medium between the plurality of scans, the image processing apparatus comprising:

• a first acquisition unit configured to acquire information on a density of an image that is be printed in the pixel region;
• a second acquisition unit configured to acquire N (≧3)-valued quantized data corresponding to the pixel region based on the image data;
• a third acquisition unit configured to acquire a plurality of dot arrangement pattern groups including at least a first dot arrangement pattern group including a plurality of first dot arrangement patterns in which an arrangement of dots is determined so that the number and position of dots that are printed within the pixel region are different in accordance with a value of the N-valued quantized data and a second dot arrangement pattern group including a plurality of second dot arrangement patterns in which an arrangement of dots is determined so that the number and position of dots that are printed within the pixel region are different in accordance with a value of the N-valued quantized data;
• a setting unit configured to set one dot arrangement pattern group from the plurality of dot arrangement pattern groups acquired by the third acquisition unit in accordance with the positions of the plurality of pixel regions within the unit region;
• and
• a generation unit configured to generate the dot printing data based on the N-valued quantized data acquired by the second acquisition unit and the dot arrangement pattern group set by the setting unit,
• wherein the number of dots that are printed within the pixel region determined by the second dot arrangement pattern corresponding to the N-valued quantized data having a predetermined value of the first and second dot arrangement pattern groups is larger than the number of dots that are printed within the pixel region determined by the first dot arrangement pattern corresponding to the N-valued quantized data having the predetermined value, and
• the setting unit sets the dot arrangement pattern group so that:
• (i) the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at a first position, that is included in an end part region of the unit region in the predetermined direction corresponding to an end part of the eject port column in the predetermined direction, in a case where the density of the image indicated by the information acquired by the first acquisition unit is a first value is smaller than the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at the first position in a case where the density of the image indicated by the information acquired by the first acquisition unit is a second value higher than the first value;
• (ii) the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at a second position, that is included in the end part region and is closer to an end of the unit region than the first position in the predetermined direction, in a case where the density of the image indicated by the information acquired by the first acquisition unit is the first value is smaller than the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at the second position in a case where the density of the image indicated by the information acquired by the first acquisition unit is the second value;
• and
• (iii) the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at the second position in a case where the density of the image indicated by the information acquired by the first acquisition unit is the second value is larger than the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at the first position in a case where the density of the image indicated by the information acquired by the first acquisition unit is the second value, and
• the number of the first dot arrangement pattern groups determined for the plurality of pixel regions located at the second position in a case where the density of the image indicated by the information acquired by the first acquisition unit is the second value is smaller than the number of the first dot arrangement pattern groups determined for the plurality of pixel regions located at the first position in a case where the density of the image indicated by the information acquired by the first acquisition unit is the second value.

An image processing apparatus that performs processing on multivalued image data corresponding to a unit region for printing an image in the unit region including a plurality of pixel regions on a printing medium by a plurality of scans of a an eject port column in which a plurality of eject ports for ejecting ink are arrayed in a predetermined direction with respect to the printing medium, wherein the plurality of eject ports ejects ink to each of the plurality of pixel regions on the printing medium in accordance with dot printing data corresponding to each of the plurality of scans, and by conveying the printing medium between the plurality of scans, the image processing apparatus comprising:

• a first acquisition unit configured to acquire information on a density of an image that is be printed in the pixel region;
• a second acquisition unit configured to acquire N (≧3)-valued quantized data corresponding to the pixel region based on the image data;
• a third acquisition unit configured to acquire a plurality of dot arrangement pattern groups including at least a first dot arrangement pattern group including a plurality of first dot arrangement patterns in which an arrangement of dots is determined so that the number and position of dots that are printed within the pixel region are different in accordance with a value of the N-valued quantized data and a second dot arrangement pattern group including a plurality of second dot arrangement patterns in which an arrangement of dots is determined so that the number and position of dots that are printed within the pixel region are different in accordance with a value of the N-valued quantized data;
• a setting unit configured to set one dot arrangement pattern group from the plurality of dot arrangement pattern groups acquired by the third acquisition unit in accordance with the positions of the plurality of pixel regions within the unit region;
• and
• a generation unit configured to generate the dot printing data based on the N-valued quantized data acquired by the second acquisition unit and the dot arrangement pattern group set by the setting unit,
• wherein the dot arrangement pattern group is set so that the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at a first position, that is included an end part region of the unit region in the predetermined direction corresponding to an end part of the eject port column in the predetermined direction, in a case where the density of the image indicated by the information acquired by the first acquisition unit is a predetermined value is smaller than the number of the second dot arrangement pattern groups determined for the plurality of pixel regions located at a second position, that is included in the end part region and is closer to an end of the unit region than the first position in the predetermined direction, in a case where the density of the image indicated by the information acquired by the first acquisition unit is the predetermined value, and
• the number of the first dot arrangement pattern groups determined for the plurality of pixel regions located at the first position in a case where the density of the image indicated by the information acquired by the first acquisition unit is the predetermined value is larger than the number of the first dot arrangement pattern groups determined for the plurality of pixel regions located at the second position in a case where the density of the image indicated by the information acquired by the first acquisition unit is the predetermined value.