Method and apparatus for image processing, and a computer product
First Claim
1. An image processing apparatus which varies resolution of an image and a gradation level of the pixels composing the image, the image processing apparatus comprising:
- a gradation direction determining unit which determines a gradation direction which is a direction of a contrast of the gradation at the pixel position of a target pixel;
a spatial frequency determining unit which determines a spatial frequency at the pixel position of the target pixel;
a dividing unit which divides the target pixel into fine pixels; and
a gradation determining unit which determines a gradation level of the fine pixel produced by the dividing unit based on the gradation level of the target pixel, the gradation direction determined by the gradation direction determining unit and the spatial frequency determined by the spatial frequency determining unit.
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Abstract
In the image processing apparatus a matrix selector selects a position matrix for determining the gradation direction. The gradation direction is the direction of a contrast of a gradation at a position of a target pixel and a dispersion matrix for determining a spatial frequency at the position of the target pixel. Further, a pixel interpolator divides the target pixel into still smaller pixels. A table selector selects a conversion table for determining a gradation level of the smaller pixels based on the gradation level of the target pixel, the position matrix and the dispersion matrix.
69 Citations
17 Claims
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1. An image processing apparatus which varies resolution of an image and a gradation level of the pixels composing the image, the image processing apparatus comprising:
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a gradation direction determining unit which determines a gradation direction which is a direction of a contrast of the gradation at the pixel position of a target pixel;
a spatial frequency determining unit which determines a spatial frequency at the pixel position of the target pixel;
a dividing unit which divides the target pixel into fine pixels; and
a gradation determining unit which determines a gradation level of the fine pixel produced by the dividing unit based on the gradation level of the target pixel, the gradation direction determined by the gradation direction determining unit and the spatial frequency determined by the spatial frequency determining unit. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An image processing apparatus which varies resolution of an image and a gradation level of the pixels composing the image, the image processing apparatus comprising:
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a gradation direction determining means for determining a gradation direction which is a direction of a contrast of the gradation at the pixel position of a target pixel;
a spatial frequency determining means for determining a spatial frequency at the pixel position of the target pixel;
a dividing means for dividing the target pixel into fine pixels; and
a gradation determining means for determining a gradation level of the fine pixel produced by the dividing means based on the gradation level of the target pixel, the gradation direction determined by the gradation direction determining means and the spatial frequency determined by the spatial frequency determining means. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. An image processing method of varying resolution of an image and gradation level of the pixels composing the image, the image processing method comprising the steps of:
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determining a gradation direction which is a direction of a contrast of the gradation at the pixel position of a target pixel;
determining a spatial frequency at the pixel position of the target pixel;
dividing the target pixel into fine pixels; and
determining a gradation level of the fine pixel produced in the dividing step based on the gradation level of the target pixel, the gradation direction determined in the gradation direction determining step and the spatial frequency determined in the spatial frequency determining step. - View Dependent Claims (16)
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17. A computer readable medium for storing instructions, which when executed by a computer, causes the computer to perform the steps of:
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determining a gradation direction which is a direction of a contrast of the gradation at the pixel position of a target pixel;
determining a spatial frequency at the pixel position of the target pixel;
dividing the target pixel into fine pixels; and
determining a gradation level of the fine pixel produced in the dividing step based on the gradation level of the target pixel, the gradation direction determined in the gradation direction determining step and the spatial frequency determined in the spatial frequency determining step.
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Specification