www.pudn.com > SR.rar > extr_lIm_fea.m, change:2011-01-28,size:433b


function [lImFea] = extr_lIm_fea( lIm ) 
 
[nrow, ncol] = size(lIm); 
 
lImFea = zeros([nrow, ncol, 4]); 
 
% first order gradient filters 
hf1 = [-1,0,1]; 
vf1 = [-1,0,1]'; 
  
lImFea(:, :, 1) = conv2(lIm, hf1, 'same'); 
lImFea(:, :, 2) = conv2(lIm, vf1, 'same'); 
 
% second order gradient filters 
hf2 = [1,0,-2,0,1]; 
vf2 = [1,0,-2,0,1]'; 
  
lImFea(:, :, 3) = conv2(lIm,hf2,'same'); 
lImFea(:, :, 4) = conv2(lIm,vf2,'same');