Image data generating apparatus and image data generating method for generating image data when an image is printed in a divided manner
First Claim
1. An image data generating apparatus that generates image data used for printing an image on a unit area of a printing medium by a plurality of scans of a printing head, said apparatus comprising:
- an obtaining unit configured to obtain a plurality of M-valued image data corresponding respectively to one scan and another scan of the plurality of scans, where M is an integer; and
a generating unit configured to generate first n-valued image data representing a gradation value of n values, where n is an integer less than M, corresponding to the one scan by executing an M value-to n value conversion process on M-valued image data corresponding to the one scan obtained by the obtaining unit, and generate second n-valued image data corresponding to the another scan by executing an M value-to n value conversion process on M-valued image data, the M-valued image data being data that is obtained by correcting a gradation value of a pixel in the unit area for the another scan on the basis of an n value of the pixel of the first n-valued image data.
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Accused Products
Abstract
The generation of dot data of planes depending on a plurality of scannings and ink colors in an ink jet printing apparatus is performed based on the error diffusion processing for each plane without causing a problem of grain. Specifically, in a binarization processing, C divided data D8c/2 is subjected to an error diffusion processing to calculate binary (dot) data D2c1 for the first pass of C. Next, M divided data D8m/2 is compensated by being added with a term of Kc1m1(D8c/2-D2c1). Then, this compensated data [D8m/2+Kc1m1(D8c/2-D2c1)] is subjected to an error diffusion processing to calculate dot data D2m1 for the first pass of M. In this manner, the generation of the respective planes performs correction to reflect the results of the binarization processing of the respective previously processed planes to subject the compensated data to an error diffusion processing.
19 Citations
17 Claims
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1. An image data generating apparatus that generates image data used for printing an image on a unit area of a printing medium by a plurality of scans of a printing head, said apparatus comprising:
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an obtaining unit configured to obtain a plurality of M-valued image data corresponding respectively to one scan and another scan of the plurality of scans, where M is an integer; and a generating unit configured to generate first n-valued image data representing a gradation value of n values, where n is an integer less than M, corresponding to the one scan by executing an M value-to n value conversion process on M-valued image data corresponding to the one scan obtained by the obtaining unit, and generate second n-valued image data corresponding to the another scan by executing an M value-to n value conversion process on M-valued image data, the M-valued image data being data that is obtained by correcting a gradation value of a pixel in the unit area for the another scan on the basis of an n value of the pixel of the first n-valued image data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An image data generating method for generating image data used for printing an image on a unit area of a printing medium by a plurality of scans of a printing head, said method comprising:
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an obtaining step of obtaining a plurality of M-valued image data corresponding respectively to one scan and another scan of the plurality of scans; and a generating step of generating first n-valued image data representing a gradation value of n values, where n is an integer less than M, corresponding to the one scan by executing an M value-to n value conversion process on M-valued image data corresponding to the one scan obtained by the obtaining step, and generating second n-valued image data corresponding to the another scan by executing an M value-to n value conversion process on M-valued image data, the M-valued image data being data that is obtained by correcting a gradation value of a pixel in the unit area for the another scan on the basis of an n value of the pixel of the first n-valued image data. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. An image data generating apparatus that generates image data used for printing an image on a unit area of a printing medium by a plurality of scans of a printing head, said apparatus comprising:
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an obtaining unit configured to obtain a plurality of M-valued image data corresponding respectively to one scan of the plurality of scans of a first color and a second color of a plurality of colors, where M is an integer; and a generating unit configured to generate first n-valued image data representing a gradation value of n values, where n is an integer less than M, corresponding to the one scan of the first color by executing an M value-to n value conversion process on M-valued image data corresponding to the one scan of the first color obtained by the obtaining unit, and generate second n-valued image data corresponding to the one scan of the second color by executing an M value-to n value conversion process on M-valued image data, the M-valued image data being data that is obtained by correcting a gradation value of a pixel of the second color in the unit area on the basis of an n value of the pixel of the first color in the first n-valued image data.
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Specification