Fixed quantizator for negative numbers and refactored haar transform

Author: iuya

Codec/codec.m

@@ -89,6 +89,7 @@
 h_sub23 = numel(huffmanCode(q_sub23))/numel(q_sub23);
 
 % We need to "stitch" all the pieces of q_lena together
+q_lena = zeros(size(lena_gray_512,1),size(lena_gray_512,2));
 q_lena(1:128,1:128) = q_sub11;
 q_lena(1:128,129:256) = q_sub12;
 q_lena(129:256,1:128) = q_sub13;
@@ -117,6 +118,7 @@
 entropies
 
 %%%%%%%% SYNTHESIS %%%%%%%%%%%%%
+dq_lena = zeros(size(lena_gray_512,1),size(lena_gray_512,2));
 dq_lena(1:128,1:128) = q_lena(1:128,1:128);
 dq_lena(1:128,129:256) = dequantize_matrix(q_lena(1:128,129:256),7,8);
 dq_lena(129:256,1:128) = dequantize_matrix(q_lena(129:256,1:128),7,8);
@@ -126,6 +128,7 @@
 dq_lena(257:512,257:512) = dequantize_matrix(q_lena(257:512,257:512),4,8);
 
 synth_lena = haar_reverse_multilevel(dq_lena,2);
+figure
 imshow(synth_lena,[0,255])
 
 %%%%%%%% PSNR calculation %%%%%%%%

Quantization/quantize_matrix.m

@@ -9,5 +9,9 @@
 
 function quantization = quantize(pixel, new_bytesize)
     dif_levels = 2^(8-new_bytesize);
-    quantization=floor(double(pixel)/dif_levels);
+    if(pixel >= 0 )
+        quantization=floor(double(pixel)/dif_levels);
+    else
+        quantization=ceil(double(pixel)/dif_levels);
+    end
 end

Transformation/haar_transform.m

@@ -18,8 +18,7 @@
         i = 1;
         for col = 1:2:size(matrix,2)
             haar_matrix(row,i) = (double(matrix(row,col)) + double(matrix(row,col+1)))/2.0;
-            c = (double(matrix(row,col)) - double(matrix(row,col+1)))/2.0;
-            haar_matrix(row,i+half_col) = c ;
+            haar_matrix(row,i+half_col) = (double(matrix(row,col)) - double(matrix(row,col+1)))/2.0; ;
             i = i + 1;
         end
     end