US 8,300,949 B2Granted

Edge detection technique having improved feature visibility

AssigneeSharp Laboratories of America, Inc.

InventorXinyu Xu

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Abstract

A method for determining edge features of an image comprising filtering at least a portion of the image to attenuate high frequency signals of the image to an extent greater than low frequency signals of the image. Performing a one-dimensional search in a two different horizontal directions relative to a particular pixel of the image to determine horizontal direction local maximums. Calculating a horizontal gradient based upon the horizontal direction local maximums. Performing a one-dimensional search in a two vertical horizontal directions relative to a particular pixel of the image to determine vertical direction local maximums. Calculating a vertical gradient based upon the vertical direction local maximums. Calculating a gradient for the particular pixel based upon the horizontal gradient and the vertical gradient.

Claims10

Dependent claims

A method for determining edge features of an image comprising:

(a) filtering at least a portion of said image to attenuate high frequency signals of said image to an extent greater than low frequency signals of said image;
(b) performing a one-dimensional search in a first horizontal direction relative to a particular pixel of said image to determine a first horizontal direction local maximum;
(c) performing a one-dimensional search in a second horizontal direction relative to said particular pixel of said image to determine a second horizontal direction local maximum;
(d) calculating a horizontal gradient based upon said first horizontal direction local maximum and said second horizontal direction local maximum;
(e) performing a one-dimensional search in a first vertical direction relative to a particular pixel of said image to determine a first vertical direction local maximum;
(f) performing a one-dimensional search in a second vertical direction relative to said particular pixel of said image to determine a second vertical direction local maximum;
(g) calculating a vertical gradient based upon said first vertical direction local maximum and said second vertical direction local maximum;
(h) calculating a gradient for said particular pixel based upon said horizontal gradient and said vertical gradient.

5 more elements

Dependencies are inferred from the claim text.