resthline Restore infrared-type images by suppressing horizontal line effects
resthline input output
input : input image
output : output image
void resthline (u , v )
Cimage u , v ;
This module removes artefacts due to grey-level shifts between horizontal lines. This problem often ocuurs with infrared images, when the captors have not been equalized. The correction is simple : from an input image u, we find the parameter k(y) so that the total variation of the output image v(x, y) = u(x, y) + k(y) is as small as possible. The algorithm minimizes the quantity | u(x, y + 1) + (y) - u(x, y)| with respect to along each line, then retrieves k(y) by k(y + 1) = k(y) + (y), and chooses k(0) in order to preserve the global mean of the input image u.
Last Modification date : Thu Nov 29 20:23:56 2001