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.
Comparison in characteristics of the image: (a) magnitude of Fourier transforms (blue solid line for original image; black dashed line for histogram equalized image; red dotted line for Gaussian smoothing filtered image with pre-histogram equalization); (b) image contrast and CNR (left y-axis for contrast with black square; right y-axis for CNR with blue circle).
