Histogram Equalization

Author: jonathanrjpereira

Histogram Equalization/histogram.bmp

@@ -0,0 +1,46 @@
+clear all
+clc
+a = imread('pout.tif');
+a = double(a);
+big = max(max(a));
+[row col] = size(a);
+C = row*col;
+h = zeros(1,300);
+z = zeros(1,300);
+for n=1:1:row
+	for m=1:1:col
+		if a(n,m) == 0
+			a(n,m) = 1;
+	end
+	end
+end
+for n=1:1:row
+	for m=1:1:col
+		t = a(n,m);
+		h(t) = h(t) + 1;
+	end
+end
+pdf = h/C;
+cdf(1) = pdf(1);
+for x=2:1:big
+cdf(x) = pdf(x) + cdf(x-1);
+end
+new = round(cdf*big);
+new = new + 1;
+for p=1:1:row
+	for q=1:1:col
+		temp = a(p,q);
+		b(p,q) = new(temp);
+		t = b(p,q);
+		z(t) = z(t)+1;
+	end
+end
+b = b-1;
+subplot(2,2,1)
+imshow(uint8(a))
+subplot(2,2,2)
+bar(h)
+subplot(2,2,3)
+imshow(uint8(b))
+subplot(2,2,4)
+bar(z)