Improved Canny edge detection method based on self-adaptive threshold

Abstract

The traditional Canny operator uses the global threshold method,but when the gray of the input image's background and foreground change largely,the global threshold method will lose some weak edge.Concerning this issue,an improved adaptive Canny operator was put forward.Firstly,the image was divided into blocks according to the gradient variance.Secondly,the threshold of the sub blocks was obtained by Otsu method.Then,the threshold matrix was got by interpolation.Finally,an improved edge connection algorithm was proposed to extract the edge with the threshold matrix.The experimental results show that the improved Canny algorithm has not only a good anti-noise function,but also a very good precision.