Image formation apparatus
First Claim
1. An image formation apparatus for converting image data including periodicity into data in a print format of a printer of an electrophotographic system, comprising:
- aperiodic data generating means for generating aperiodic data between pixel areas having a neighboring relation every pixel area comprising a plurality of pixels having an interlocking relation of said image data;
threshold value deciding means for converting said aperiodic data into a plurality of threshold data for forming a systematic dot array in said pixel area; and
gradation conversion processing means for performing a gradation converting process by comparing said image data with said threshold data.
1 Assignment
0 Petitions
Accused Products
Abstract
An image formation apparatus includes an aperiodic data generating unit for generating aperiodic data between pixel areas having a neighboring relation every pixel area comprising a plurality of pixels having an interlocking relation of the image data, a threshold value deciding unit for converting the aperiodic data into a plurality of threshold data for forming a systematic dot array in the pixel area, and a gradation conversion processing unit for performing a gradation converting process by comparing the image data with the threshold data, thereby reducing a signal processing amount as compared with that in case of performing the propagating process on a pixel unit basis.
-
Citations
14 Claims
-
1. An image formation apparatus for converting image data including periodicity into data in a print format of a printer of an electrophotographic system, comprising:
-
aperiodic data generating means for generating aperiodic data between pixel areas having a neighboring relation every pixel area comprising a plurality of pixels having an interlocking relation of said image data; threshold value deciding means for converting said aperiodic data into a plurality of threshold data for forming a systematic dot array in said pixel area; and gradation conversion processing means for performing a gradation converting process by comparing said image data with said threshold data. - View Dependent Claims (2, 3, 7, 8, 14)
-
-
4. An image formation apparatus for converting image data including periodicity into data in a print format of a printer of an electrophotographic system, comprising:
-
a blue noise mask storing unit for storing a blue noise mask; threshold value deciding means for allowing each threshold value of said blue noise mask to correspond to each pixel area comprising a plurality of pixels having an interlocking relation of said image data and converting the threshold value of said blue noise mask into a plurality of threshold data for forming a systematic dot array in said pixel area; and gradation conversion processing means for performing a gradation converting process by comparing performing a gradation converting process by comparing said image data with said threshold data. - View Dependent Claims (5, 6)
-
-
9. An image formation apparatus for converting image data including periodicity into data in a print format of a printer of an electrophotographic system, comprising:
-
gradation conversion processing means for using a dither matrix in which a plurality of threshold value areas each comprising a plurality of threshold data having an interlocking relation are arranged and performing a gradation conversion by comparing said image data with the threshold data of said dither matrix, wherein each of said threshold data in said threshold value area is threshold data for forming a systematic dot array in said threshold value area, and the dither matrix in which only the largest threshold data has been extracted in said threshold value area is aperiodic between the threshold data having a neighboring relation. - View Dependent Claims (10, 12, 13)
-
-
11. An image formation apparatus for converting image data including periodicity into data in a print format of a printer of an electrophotographic system, comprising:
-
gradation conversion processing means for using a dither matrix in which a plurality of threshold value areas each comprising a plurality of threshold data having an interlocking relation are arranged and performing a gradation conversion by comparing each pixel of said image data with each of said threshold data of said dither matrix, wherein said dither matrix is obtained in a manner such that each threshold value of a blue noise mask is made to correspond to each threshold value area in said dither matrix, the threshold value of said blue noise mask is converted into a plurality of threshold data for forming a systematic dot array in said threshold value area, and said plurality of threshold data is arranged, and the dither matrix in which only the largest threshold data has been extracted in said threshold value area has frequency characteristics similar to those of said blue noise mask.
-
Specification