Method for extracting edge in photogrammetry with subpixel accuracy

摘要

A method for extracting edge with subpixel accuracy in photogrammetry, comprising steps of: a. capturing into a computer a picture, of which the edge is to be extracted; b. defining as a cell four neighboring pixels that form a square; c. recognizing the type of each cell composed of the four pixels; d. finding out side or sides of the cell that intersect with, the edge and figuring out the subpixel accuracy coordinates of the intersection points by linear interpolation; and e. connecting the intersection points to extract the edge. By this method edge curve is extracted rapidly and accurately. The edge determined in this way can be subpixel accurate.