PRINTING APPARATUS, PRINTING METHOD, AND IMAGE PROCESSING APPARATUS
First Claim
1. A printing apparatus adapted to print an image based on image data, the printing apparatus comprising:
- an input section where the image data is input;
a halftone processing section configured to generate dot data which represents whether or not dots are formed by processing the image data using an error diffusion method; and
a print section configured to perform printing of the image using the dot data which is generated,wherein the halftone processing section includesa comparator configured to compare a first threshold which is aligned with a dither mask and the image data which is input,a threshold setting section configured to set a second threshold which is used in the error diffusion method to one of a low threshold and a high threshold whose values are different to each other according to results of the comparing, and to set the low threshold to a value which is smaller than a gradation range of the image data in at least a low gradation area in a case where it is determined that the image data exceeds the first threshold, andan error diffusion section configured to generate the dot data and to calculate distribution to pixels in the vicinity of gradation errors, which are generated as a result of generating the dot data, by comparing correction data where error distribution in the image data is complete using the error diffusion method and the low threshold or the high threshold which is set.
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Abstract
The printing apparatus includes a comparator, a threshold setting section, and an error diffusion section. The comparator compares a first threshold which is aligned with a dither mask and the image data. The threshold setting section sets a second threshold which is used in the error diffusion method to one of a low threshold and a high threshold according to results of the comparing, and sets the low threshold to a value which is smaller than a gradation range of the image data in at least a low gradation area when it is determined that the image data exceeds the first threshold. The error diffusion section generates the dot data and to calculate distribution to pixels in the vicinity of gradation errors by comparing correction data where error distribution in the image data is complete using the error diffusion method and the low threshold or the high threshold.
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Citations
8 Claims
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1. A printing apparatus adapted to print an image based on image data, the printing apparatus comprising:
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an input section where the image data is input; a halftone processing section configured to generate dot data which represents whether or not dots are formed by processing the image data using an error diffusion method; and a print section configured to perform printing of the image using the dot data which is generated, wherein the halftone processing section includes a comparator configured to compare a first threshold which is aligned with a dither mask and the image data which is input, a threshold setting section configured to set a second threshold which is used in the error diffusion method to one of a low threshold and a high threshold whose values are different to each other according to results of the comparing, and to set the low threshold to a value which is smaller than a gradation range of the image data in at least a low gradation area in a case where it is determined that the image data exceeds the first threshold, and an error diffusion section configured to generate the dot data and to calculate distribution to pixels in the vicinity of gradation errors, which are generated as a result of generating the dot data, by comparing correction data where error distribution in the image data is complete using the error diffusion method and the low threshold or the high threshold which is set. - View Dependent Claims (2, 3, 4, 5)
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6. A printing method for printing an image based on image data, the printing method comprising:
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inputting the image data; setting a second threshold which is used in an error diffusion method to one of a low threshold and a high threshold whose values are different to each other by comparing a first threshold which is aligned with a dither mask and the image data, and setting the low threshold to a value which is smaller than a gradation range of the image data in at least a low gradation area in a case where it is determined that the image data exceeds the first threshold when dot data which represents whether or not dots are formed is generated from the image data by performing a halftone process according to the error diffusion method, and generating the dot data and calculating distribution of pixels in the vicinity of gradation errors, which are generated as a result of generating the dot data, by comparing correction data where error distribution in the image data is complete using the error diffusion method and the low threshold or the high threshold which is set; and performing printing of the image using the dot data which is generated.
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7. An image processing apparatus adapted to generate dot data which represents whether or not dots are formed by processing image data which represents a predetermined image, the image processing apparatus comprising:
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an input section where the image data is input; and a halftone processing section configured to generate the dot data by processing the image data using an error diffusion method, wherein the halftone processing section includes a comparator which compares a first threshold which is aligned with a dither mask and the image data which is input, a threshold setting section configured to set a second threshold which is used in the error diffusion method to one of a low threshold and a high threshold whose values are different to each other according to results of the comparing, and to set the low threshold to a value which is smaller than a gradation range of the image data in at least a low gradation area in a case where it is determined that the image data exceeds the first threshold, and an error diffusion section configured to generate the dot data and to calculate distribution to pixels in the vicinity of gradation errors, which are generated as a result of generating the dot data, by comparing correction data where error distribution in the image data is completed using the error diffusion method and the low threshold or the high threshold which is set.
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8. An image data processing apparatus adapted to generate dot data for printing by image data being input, the image data processing apparatus comprising:
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a first halftone processing section configured to generate provisional dot data which provisionally determines whether or not dots are formed by comparing with various thresholds of a dither mask which contains a plurality of thresholds; and a second halftone processing section configured to determine that dots are formed without any changes in a case where the provisional dot data indicates a result where it is determined that that the dots are formed, and to determine whether or not dots are formed by applying an error diffusion method to the image data in a case where the provisional dot data indicates a result where it is determined that that dots are not formed.
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Specification