An Edge Detection Algorithm Based on Improved CANNY Operator

Edge detection is an important aspect for image processing, and primary step of spatial data extraction in geography information system. For contour detection, this paper proposed the improved template algorithm, which is not only including the gradient directions of X and Y, but also the first order partial finite differences of directions 45 and 135 degree in calculating the amplitude values. These mostly improved the calculation accuracy of the amplitude values. In the non-maxima suppression process, the factor ratio of four quadrants of linear interpolation is improved to achieve better detection results. Experiments showed that this improved CANNY algorithm has better noise suppression and edge continuity.