Hough Transform
The Hough Transform (HT) has been recognized as a very powerful tool for the detection of parametric curves in
images[12], [13].
It is implemented by a voting process that maps image edge points into manifolds in a properly defined parameter space.
The Circular Hough Transform (CHT) is one of the modified versions of the HT.
The purpose of using CHT is to find the circular patterns within an image scene [14].
The CHT is used to transform a set of feature points in the image space into a set of accumulated votes in a parameter space.
Then, for each feature point, votes are accumulated in an accumulator array for all parameter combinations.
The array elements that contain the highest number of votes indicate the presence of the shape.