Image processor and image processing program for binary processing
First Claim
1. An image processor for converting input image data that has multi-grayscale image data for each pixel with a predetermined resolution into binary data for each of said pixels, comprising:
- a binary unit, whereinif a grayscale value of multi-grayscale image data of a processing target pixel is lower than a reference value, which is less than ½
of a maximum grayscale value of said multi-grayscale image data, said binary unit performs a first binary processing for converting the input image data of said processing target pixel into binary data of “
dot present”
or “
dot absent”
based on a threshold matrix, in which a plurality of threshold values are dispersed without concentrating a plurality of low threshold values, andif the grayscale value of the multi-grayscale image data of the processing target pixel is higher than said reference value, said binary unit performs a second binary processing for converting the input image data of said processing target pixel into binary data of “
dot present”
, and an error diffusion processing for adding an error between the grayscale value of said processing target pixel and the maximum grayscale value to said multi-grayscale image data of peripheral pixels based on a first error diffusion matrix.
1 Assignment
0 Petitions
Accused Products
Abstract
An image processor for converting input multi-grayscale image data, into binary data for each of the pixels has a binary unit. If a grayscale value of the multi-grayscale image data of a target pixel is lower than a reference value less than ½ of a maximum grayscale value, the binary unit converts the input image data into the binary data of a “dot present” or “dot absent” based on a threshold matrix, in which a plurality of threshold values are dispersed without concentrating a plurality of low threshold values, and if the grayscale value of the multi-grayscale image data is higher than the reference value, the binary unit converts the input image data into the binary data of a “dot present”, and propagating an error by adding the error to the peripheral pixels based on a first error diffusion matrix.
4 Citations
24 Claims
-
1. An image processor for converting input image data that has multi-grayscale image data for each pixel with a predetermined resolution into binary data for each of said pixels, comprising:
a binary unit, wherein if a grayscale value of multi-grayscale image data of a processing target pixel is lower than a reference value, which is less than ½
of a maximum grayscale value of said multi-grayscale image data, said binary unit performs a first binary processing for converting the input image data of said processing target pixel into binary data of “
dot present”
or “
dot absent”
based on a threshold matrix, in which a plurality of threshold values are dispersed without concentrating a plurality of low threshold values, andif the grayscale value of the multi-grayscale image data of the processing target pixel is higher than said reference value, said binary unit performs a second binary processing for converting the input image data of said processing target pixel into binary data of “
dot present”
, and an error diffusion processing for adding an error between the grayscale value of said processing target pixel and the maximum grayscale value to said multi-grayscale image data of peripheral pixels based on a first error diffusion matrix.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 17)
-
11. A computer readable medium storing an image processing program for converting input image data that has multi-grayscale image data for each pixel with a predetermined resolution into binary data for each of said pixels, wherein
if a grayscale value of multi-grayscale image data of a processing target pixel is lower than a reference value, which is less than ½ - of a maximum grayscale value of said multi-grayscale image data, the program causes a computer to perform a first binary processing step of converting the input image data of said processing target pixel into binary data of “
dot present”
or “
dot absent”
based on a threshold matrix, in which a plurality of threshold values are dispersed without concentrating a plurality of low threshold values, andif the grayscale values of the multi-grayscale image data of the processing target pixel is higher than said reference value, the program causes the computer to perform a second binary processing step of converting the input image data of said processing target pixel into binary data of “
dot present”
, and an error diffusion processing step of adding an error between the grayscale value of said processing target pixel and the maximum grayscale value to said multi-grayscale image data of peripheral pixels based on a first error diffusion matrix.
- of a maximum grayscale value of said multi-grayscale image data, the program causes a computer to perform a first binary processing step of converting the input image data of said processing target pixel into binary data of “
-
12. An image processor for converting input image data, that has multi-grayscale image data for each pixel with a predetermined resolution, into binary data for each of the pixels, comprising:
a binary unit, which performs a binary processing for converting the input image data of the processing target pixel into binary data of “
dot present”
or “
dot absent”
based on a threshold matrix, in which a plurality of threshold values are arranged, and an error diffusion processing for adding an error between the input grayscale value of the “
dot present”
pixel and the maximum grayscale value to the multi-grayscale image data of peripheral pixels based on a first error diffusion matrix, and adding an error between the input grayscale value of the pixel of “
dot absent” and
the minimum grayscale value to the multi-grayscale image data of peripheral pixels based on a second error diffusion matrix which is different from the first error diffusion matrix.- View Dependent Claims (13, 14, 15, 16)
-
18. An image processor for converting input image data, that has multi-grayscale image data for each pixel with a predetermined resolution, into binary data for each of the pixels, comprising:
-
a binary unit, wherein if a grayscale value of the multi-grayscale image data of a processing target pixel is lower than a reference value, which is less than ½
of a maximum grayscale value of the multi-grayscale image data, the binary unit performs binary processing for converting the input image data of the processing target pixel into the binary data of “
dot present”
or “
dot absent”
based on the threshold matrix, in which a plurality of threshold values are dispersed without concentrating a plurality of low threshold values, and the binary unit performs an error diffusion processing for adding an error of the processing target pixel generated by the binary processing to the multi-grayscale image data of peripheral pixels. - View Dependent Claims (19, 20)
-
-
21. A computer readable medium storing an image processing program for converting input image data, that has multi-grayscale image data for each pixel with a predetermined resolution, into binary data for each of the pixels, the image processing program causing a computer to perform:
-
a binary processing step of converting the input image data of the processing target pixel into binary data of “
dot present”
or “
dot absent”
based on a threshold matrix, in which a plurality of threshold values are arranged, andan error diffusion processing step of adding an error between the input grayscale value of the “
dot present”
pixel and the maximum grayscale value to the multi-grayscale image data of peripheral pixels based on a first error diffusion matrix, and adding an error between the input grayscale value of the pixel of “
dot absent” and
the minimum grayscale value to the multi-grayscale image data of peripheral pixels based on a second error diffusion matrix which is different from the first error diffusion matrix.
-
-
22. A computer readable medium storing an image processing program medium for converting input image data, that has multi-grayscale image data for each pixel with a predetermined resolution, into binary data for each of the pixels, the image processing program causing a computer to perform:
if a grayscale value of the multi-grayscale image data of a processing target pixel is lower than a reference value, which is less than ½
of a maximum grayscale value of the multi-grayscale image data, a binary processing step of converting the input image data of the processing target pixel into the binary data of “
dot present”
or “
dot absent”
based on the threshold matrix, in which a plurality of threshold values are dispersed without concentrating a plurality of low threshold values, and an error diffusion processing step of adding an error of the processing target pixel generated by the binary processing to the multi-grayscale image data of peripheral pixels.
-
23. An image processor for converting input image data, that has multi-grayscale image data for each pixel with a predetermined resolution, into binary data for each of the pixels, comprising:
-
a binary unit, wherein if a grayscale value of the multi-grayscale image data of a processing target pixel is lower than a reference value, which is less than ½
of a maximum grayscale value of the multi-grayscale image data, said binary unit performsa first binary processing for converting the input image data of the processing target pixel into the binary data of “
dot present”
or “
dot absent”
based on the threshold matrix, in which a plurality of threshold values are dispersed without concentrating a plurality of low threshold values, and a first error diffusion processing for adding an error between the input grayscale value of the “
dot present”
pixel and the maximum grayscale value to the multi-grayscale image data of peripheral pixels based on a first error diffusion matrix, and adding an error between the input grayscale value of the pixel of “
dot absent” and
the minimum grayscale value to the multi-grayscale image data of peripheral pixels based on a second error diffusion matrix which is different from the first error diffusion matrix,if the grayscale values of the multi-grayscale image data of the processing target pixel is higher than said reference value, the binary unit performs a second binary processing for converting said processing target pixel into binary data of “
dot present”
, and a second error diffusion processing for adding an error between the input grayscale value of said processing target pixel and the maximum grayscale value to said multi-grayscale image data of peripheral pixels based on a first error diffusion matrix. - View Dependent Claims (24)
-
Specification