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US 2014/0153834 A1Published application
Hough transform for circles
AssigneeAnalog Devices, Inc.
InventorsBijesh Poyil, Anil M. Sripadarao
Life of this patent
Estimating the term…
Abstract
The Hough transform for circles can be implemented in a manner that avoids random access to the Hough accumulator array by successively identifying center candidates in each line of the image based on edge pixels in corresponding lines voting on the line of interest.
Claims22
A method for detecting circles in digital images, the method comprising:
- (a) computationally detecting edge pixels in an image and storing coordinate information of the detected edge pixels in a plurality of edge buffers based on edge angles associated with the pixels;
- and
- (b) computationally identifying, successively in each of at least one selected line of the image, centers of circles having radii within a specified range by (i) identifying, for each edge angle, lines of edge pixels whose distance from the selected line is within the specified range of radii, (ii) parsing the identified lines of edge pixels and, based at least in part on the edge angle and the coordinate information of the detected edge pixels, accumulating votes from the edge pixels on the selected line, and (iii) identifying the centers in the selected lines based at least in part on the accumulated votes.
A system for detecting circles in a digital image comprising a stored array of pixels, the system comprising:
- memory for storing coordinate information of edge pixels in the image in a plurality of edge buffers based on edge angles associated with the pixels;
- and
- a processor configured to identify, successively in each of at least one selected line of the image, centers of circles having radii within a specified range by (i) identifying, for each edge angle, lines of edge pixels whose distance from the selected line is within the specified range of radii, (ii) parsing the identified lines of edge pixels and, based at least in part on the edge angle and the coordinate information of the detected edge pixels, accumulating votes from the edge pixels on the selected line, and (iii) identifying the centers in the selected lines based at least in part on the accumulated votes.
Dependencies are inferred from the claim text.