A Method to Improve Accuracy of Votes in Hough Transform Using Variable-sized Directional Image Filter
Fumihiko Saitoh · IEEJ Transactions on Electronics Information and Systems · 2001
Hough transform is known as a useful method to extract a global figure in an image through the voting process into the parameter space. Because Hough transform uses the information about the edge pixels in an image for the voting process, the accuracy of the direction of each edge pixel influences on the reliability of the voted result. This paper proposes a method to raise the reliability of the voting process in Hough transform by improving the accuracy of the direction of an edge pixel using the directional adaptive filter. The direction and the width of the directional filter are determined dynamically by the direction and the curvature of the edge pixel. Experimental results show that the voted result with the sharper maximum peaks are obtained by the proposed method in comparison with the method that uses the direction of the independent edge pixel and the method that uses the averaged direction of neighboring edge pixels.