Circuit and method for contour enhancement
AssigneeFujitsu Limited
InventorsShigeru Nishio, Hiroshi Daiku, Asao Kokubo
Life of this patent
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Abstract
A semiconductor integrated circuit includes a differential calculating unit which obtains a differential between a value of a pixel of interest and values of surrounding pixels contained in an image signal supplied from an image sensor, a dead-zone generating unit which defines a predetermined range of pixel values, and a comparison unit which checks whether the differential falls outside the predetermined range, wherein contour enhancement is applied to the pixel of interest in response to a determination by the comparison unit that the differential falls outside the predetermined range.
Claims7
A semiconductor integrated circuit, comprising:
- a differential calculating unit which obtains a differential between a value of a pixel of interest and a value of an adjacent pixel with respect to each of four neighboring pixels contained in an image signal supplied from an image sensor;
- a dead-zone generating unit which defines a predetermined range of pixel values;
- and
- a comparison unit which checks whether the differential falls outside the predetermined range with respect to each of the four neighboring pixels,
- wherein contour enhancement is applied to the pixel of interest in response to a determination by the comparison unit that the differential falls outside the predetermined range with respect to at least one of the four neighboring pixels,
- wherein an enhancement value generating unit selects a differential having a largest absolute value among each said differential corresponding to the four neighboring pixels, and performs said contour enhancement in response to the differential having the largest absolute value,
- and wherein said contour enhancement is not performed if a largest differential among each said differential and a smallest differential among each said differential have opposite signs but have an identical absolute value regardless of whether the largest differential and the smallest differential fall outside the predetermined range.
A method of enhancing contours, comprising the steps of:
- obtaining a differential between a value of a pixel of interest and a value of an adjacent pixel with respect to each of four neighboring pixels contained in an image signal supplied from an image sensor;
- defining a predetermined range of pixel values;
- checking whether the differential falls outside the predetermined range with respect to each of the four neighboring pixels;
- and
- applying contour enhancement to the pixel of interest in response to a determination that the differential falls outside the predetermined range with respect to at least one of the four neighboring pixels, wherein a differential having a largest absolute value among each said differential corresponding to the four neighboring pixels is selected, and said contour enhancement is performed in response to the differential having the largest absolute value, and wherein said contour enhancement is not performed if a largest differential among each said differential and a smallest differential among each said differential have opposite signs but have an identical absolute value regardless of whether the largest differential and the smallest differential fall outside the predetermined range.
Dependencies are inferred from the claim text.