Information processing apparatus, image processing apparatus and method thereof, which create and use a halftone screen
AssigneeCanon Kabushiki Kaisha
InventorNaoto Kawamura
Life of this patent
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Abstract
A halftone screen which is applicable to a low-resolution electrophotographic printer is created. Hence, dot-lattice points arranged in a predetermined region are displaced using rotation processing, the predetermined region is partitioned into polygons each of which surrounds the dot-lattice point. Then, a threshold matrix used to grow a halftone dot, which is surrounded by each polygon, in a direction of the displacement is generated.
Claims14
An information processing apparatus comprising:
- a displacement section arranged to displace dot-lattice points arranged in a predetermined region using rotation processing;
- a partition section arranged to partition the predetermined region into polygons each of which surrounds the displaced dot-lattice point;
- and
- a generator arranged to generate a threshold matrix used to grow a halftone dot, which is surrounded by each polygon, in a direction of the displacement.
An image processing apparatus comprising:
- a memory, arranged to store a threshold matrix generated by an information processing apparatus which includes,
- a displacement section arranged to displace dot-lattice points arranged in a predetermined region using rotation processing;
- a partition section arranged to partition the predetermined region into polygons each of which surrounds the displaced dot-lattice point;
- and
- a generator arranged to generate a threshold matrix used to grow a halftone dot, the generator surrounded by each polygon, in a direction of the displacement;
- a comparator arranged to input image data and the threshold matrix from the memory in synchronism with synchronizing signals of the image forming apparatus, and to compare the image data with threshold values in cells of the threshold matrix;
- and
- a driver arranged to drive a laser light source of the image forming apparatus in accordance with the comparison result.
An image processing apparatus comprising:
- a memory configured to store a threshold matrix;
- a comparator arranged to input image data and the threshold matrix from the memory in synchronism with synchronizing signals of an image forming apparatus, and to compare the image data with threshold values in cells of the threshold matrix;
- and
- a driver arranged to drive a laser light source of the image forming apparatus in accordance with the comparison result,
- wherein the threshold values in cells are arranged to concentrate blank regions in portions of an area corresponding to the threshold matrix.
An information processing method, comprising:
- displacing dot-lattice points arranged in a predetermined region using rotation processing;
- partitioning the predetermined region into polygons each of which surrounds the displaced dot-lattice point;
- and
- generating a threshold matrix used to grow a halftone dot, which is surrounded by each polygon, in a direction of the displacement.
A non-transitory computer-readable medium storing a computer-executable program for causing a computer to perform an information processing method, the method comprising:
- displacing dot-lattice points arranged in a predetermined region using rotation processing;
- partitioning the predetermined region into polygons each of which surrounds the displaced dot-lattice point;
- and
- generating a threshold matrix used to grow a halftone dot which is surrounded by each polygon in a direction of the displacement.
Dependencies are inferred from the claim text.