Method for smoothing jagged edges in digital images
AssigneeCanon Kabushiki Kaisha
InventorDelphine Anh Dao Le
Life of this patent
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Abstract
A method of smoothing jagged edges in graphical data. The method detects one or more edge of a selected pixel in the graphical data, dependent upon intensities of the selected pixel and another pixel surrounding a respective site of one or more edges and predetermied gradients of at least the selected pixel and the respective site surrounding the pixel. An adapted convolution mask is applied to the selected pixel and a predetermined neighborhood of pixels containing the selected pixel. The coefficient values of the convolution mask are dependent upon one or more detected edges.
Claims84
A method of smoothing jagged edges of oblique lines or curves in a digital image, said method comprising the steps of:
- detecting one or more edges of a selected pixel in the digital image, wherein a candidate edge of the selected pixel for detection is detected dependent upon intensities of the selected pixel and a further pixel abutting the candidate edge of the selected pixel, predetermined gradients of at least the selected pixel and the further pixel, and predetermined gradients of one or more pixels diagonally adjacent the selected pixel;
- and
- modifying the selected pixel by applying a convolution mask to the selected pixel and a predetermined neighbourhood of pixels containing the selected pixel so as to smooth oblique edges without blurring horizontal or vertical edges, wherein coefficient values of the convolution mask are dependent upon the one or more detected edges.
An apparatus for smoothing jagged edges of oblique lines or curves in a digital image, said apparatus comprising:
- means for detecting one or more edges of a selected pixel in the digital image, wherein a candidate edge of the selected pixel for detection is detected dependent upon intensities of the selected pixel and a further pixel abutting the candidate edge of the selected pixel, predetermined gradients of at least the selected pixel and the further pixel, and predetermined gradients of one or more pixels diagonally adjacent the selected pixel;
- and
- means for modifying the selected pixel by applying a convolution mask to the selected pixel and a predetermined neighbourhood of pixels containing the selected pixel so as to smooth oblique edges without blurring horizontal or vertical edges, wherein coefficient values of the convolution mask are dependent upon the one or more detected edges.
A computer program product including a computer readable medium having recorded thereon a computer program for smoothing jagged edges of oblique lines or curves in a digital image, said computer program product comprising:
- means for detecting one or more edges of a selected pixel in the digital image, wherein a candidate edge of the selected pixel for detection is detected dependent upon intensities of the selected pixel and a further pixel abutting the candidate edge of the selected pixel, predetermined gradients of at least the selected pixel and the further pixel, and predetermined gradients of one or more pixels diagonally adjacent the selected pixel;
- and
- means for modifying the selected pixel by applying a convolution mask to the selected pixel and a predetermined neighbourhood of pixels containing the selected pixel so as to smooth oblique edges without blurring horizontal or vertical edges, wherein coefficient values of the convolution mask are dependent upon the one or more detected edges.
The computer program product according to clam 67, wherein said predetermined value is zero.
Dependencies are inferred from the claim text.