Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Edge detection by the Sobel operator in the vertical direction. (a): An example deformed image with horizontal features; (b): Edge detection result of (a); (c): An example deformed image with vertical features; (d): Edge detection result of (d).
