| 摘要 |
PROBLEM TO BE SOLVED: To improve processing efficiency of Canny edge detection with a smaller internal buffer than the case where processing results of each of stages are stored in each of pixels in an image.SOLUTION: An edge detection method includes: first processing that calculates gradient intensity of a pixel-of-interest value, which is a pixel value in a pixel of interest in an image, and a gradient direction of the pixel-of-interest value, and refers gradient intensity of a pixel value of a first pixel, in which gradient of a pixel value has been calculated, of pixel values of pixels adjacent to the pixel of interest, in non-maximum suppression of the pixel-of-interest value, every time the gradient of the pixel-of-interest value is calculated, so as to be compared with the gradient intensity of the pixel-of-interest value; and second processing that refers to the gradient intensity of the pixel-of-interest value so as to be compared with the gradient intensity of the pixel value of the first pixel, in non-maximum suppression on each first pixel. On the basis of comparison between a first threshold and a second threshold larger than the first threshold and each of gradient intensity of a pixel value of a second pixel surrounded by a pixel including the first pixel and having been subjected to non-maximum suppression and the gradient intensity of the pixel values of pixels surrounding the second pixel, respectively, it is determined whether the second pixel is an edge or not.SELECTED DRAWING: Figure 1 |
