add Histogram Equalization files

Author: mohadeseh-ghafoori

Histogram Equalization/hw2_histeq.m

@@ -0,0 +1,26 @@
+%mohadeseh ghafoori 9632133
+function [im_eq]=hw2_histeq(im)
+[m,n]=size(im);
+img=uint8(im);
+h=zeros(1,256);
+for i=1:m
+    for j=1:n
+      h(1,img(i,j)+1)=h(1,img(i,j)+1)+1; 
+    end
+end
+h_prob=h/(m*n);   %matrix probability of image for each lighting level
+for j=1:256
+    if (j==1) im_cdf(1,1)=h_prob(1,1);
+    else im_cdf(1,j)=im_cdf(1,j-1)+h_prob(1,j);
+    end
+end
+eq=255*im_cdf;
+for i=1:m
+    for j=1:n
+      im_eq(i,j)=eq(1,img(i,j)+1);  
+    end
+end
+im_eq=uint8(im_eq);
+imshow(im_eq)
+title('new equlized image');
+end