Line distance calculation method, line distance calculation apparatus, computer program, and computer-readable storage medium

摘要

The present disclosure discloses a line distance calculation method and a line distance calculation apparatus. The inter-line distance calculation method includes obtaining an original image, performing grayscale processing to generate a grayscale image, and generating a normal direction image and a tangential direction image based on the grayscale image. Generating a smoothed image by filtering the grayscale image based on the tangential image, converting the smoothed image into a binary image, dividing the binary image into a plurality of blocks, The step of determining the normal direction of the center point of each block based on the line direction image, and traversing the pixels in the normal direction of the center point of each block, the pixel values of two adjacent pixels in each block are Calculating the number of times of change between the first pixel value and the second pixel value, calculating the coordinates of the boundary point corresponding to the change point and the sub-pixel value, the number of changes, and the change point; Based on the coordinates and the sub-pixel value of the boundary point, and generating the inter-line distance, a. The line distance calculation method searches for the boundary point between the ridge and valley lines of the fingerprint and calculates the line distance based on the coordinates of the boundary point and the sub-pixel value.