Circle detection with incomplete edges

1. What algorithm is used to detect circles?
2. How can I identify a circle in an image?
3. How does Hough circle transform work?

What algorithm is used to detect circles?

Automatic circle detection is an important element of many image processing algorithms. Traditionally the Hough transform has been used to find circular objects in images but more modern approaches that make use of heuristic optimisation techniques have been developed.

How can I identify a circle in an image?

In order to detect the circles, or any other geometric shape, we first need to detect the edges of the objects present in the image. The edges in an image are the points for which there is a sharp change of color. For instance, the edge of a red ball on a white background is a circle.

How does Hough circle transform work?

The circle Hough Transform (CHT) is a basic feature extraction technique used in digital image processing for detecting circles in imperfect images. The circle candidates are produced by “voting” in the Hough parameter space and then selecting local maxima in an accumulator matrix.