US 2008/0165206 A1 · Edge-Oriented Interpolation Method and System for a Digital Image

Abstract

An edge-oriented interpolation method is used for enlarging a source image. The region in which each destination pixel in an enlarged image is located is identified as a smooth region, a text region or an edge region, and Sobel edge detection for two adjacent pixels around the destination pixel is performed to obtain two Sobel gradients. When the destination pixel is located in a smooth region, cubic convolution interpolation is performed for the destination pixel with a first slope. When the destination pixel is located in a text region, cubic convolution interpolation is performed for the destination pixel with a second slope. When the destination pixel is located in an edge region, Sobel-based interpolation for the destination pixel is performed with the two Sobel gradients.

Claims20

Dependent claims

An edge-oriented interpolation method for a digital image, comprising the steps of:

identifying each destination pixel as being located in a smooth region, a text region or an edge region of the digital image;
performing Sobel edge detection for two neighboring pixels around the destination pixel to obtain two Sobel gradients;
performing cubic convolution interpolation for the destination pixel with a first slope when the destination pixel is identified to be located in a smooth region;
performing cubic convolution interpolation for the destination pixel with a second slope when the destination pixel is identified to be located in a text region, wherein the second slope is different from the first slope;
and
performing Sobel-based interpolation for the destination pixel with reference to the two Sobel gradients when the destination pixel is identified to be located in an edge region.

3 more elements

An edge-oriented interpolation system for a digital image, comprising:

a region determination circuit identifying each destination pixel as being located in a smooth region, a text region or an edge region of the digital image;
a Sobel edge detector performing Sobel edge detection for two neighboring pixels around the destination pixel to obtain two Sobel gradients;
and
an interpolator adaptively performing cubic convolution interpolation with a given slope or Sobel-based interpolation employing the two Sobel gradients depending on the identification of the destination pixel by the region determination circuit as being located in the smooth region, the text region or the edge region of the digital image.

1 more element

Dependencies are inferred from the claim text.

Edge-Oriented Interpolation Method and System for a Digital Image

Life of this patent

Edge-Oriented Interpolation Method and System for a Digital Image

Life of this patent

Abstract

Claims20