Circular arcs detected in a digital image by our algorithm.
Sahadev Bera, Partha Bhowmick, and Bhargab B. Bhattacharya,
Detection of Circular Arcs in a Digital Image Using Chord and Sagitta Properties,
Graphics Recognition—Achievements, Challenges, and Evolution,
Lecture Notes in Computer Science (LNCS), Springer, vol. 6020, pp. 69-80, 2010.
(Selected papers from 8th International Workshop on Graphics Recognition (GREC 2009): La Rochelle, France)
We have designed a fast and efficient algorithm for detection of digital circles and circular arcs from digital images using chord property and sagitta property. It is shown how a variant of the chord property of an Euclidean circle can be used to detect a digital circle or a circular arc. Based on this property, digital circular arcs are first extracted and then using the sagitta property, their centers and radii are computed. Several arcs are merged together to form a complete digital circle or a larger arc. Finally, a novel technique of restricted Hough transform (RHT) is used to improve the accuracy of computing the centers and radii. Experimental results have been furnished to demonstrate the efficiency of the proposed method.
