%% Matlab code for Image Compression Using Run Length Encoding
clc;
clear;
close all;
%% Set Quantization Parameter
quantizedvalue=100;
%% Read Input Image
InputImage=imread('cameraman.tif');
[row col p]=size(InputImage);
%% Wavelet Decomposition
[LL LH HL HH]=dwt2(InputImage,'haar');
WaveletDecomposeImage=[LL,LH;HL,HH];
imshow(WaveletDecomposeImage,[]);
%% Uniform Quantzation
QuantizedImage= WaveletDecomposeImage/quantizedvalue;
QuantizedImage= round(QuantizedImage);
ImageArray=toZigzag(QuantizedImage)
%% Run Length Encoding
j=1;
a=length(ImageArray);
count=0;
for n=1:a
b=ImageArray(n);
if n==a
count=count+1;
c(j)=count;
s(j)=ImageArray(n);
elseif ImageArray(n)==ImageArray(n+1)
count=count+1;
elseif ImageArray(n)==b
count=count+1;
c(j)=count;
s(j)=ImageArray(n);
j=j+1;
count=0;
end
end
%% Transmission Variables c contains count s contains symbol
c;
s;
%% Calculation Bit Cost
InputBitcost=row*col*8;
InputBitcost=(InputBitcost);
c1=length(c);
s1=length(s);
OutputBitcost= (c1*8)+(s1*8);
OutputBitcost=(OutputBitcost);
%% Run Length Decoding
g=length(s);
j=1;
l=1;
for i=1:g
v(l)=s(j);
if c(j)~=0
w=l+c(j)-1;
for p=l:w
v(l)=s(j);
l=l+1;
end
end
j=j+1;
end
ReconstructedImageArray=v;
%% Inverse ZigZag
ReconstructedImage=invZigzag(ReconstructedImageArray)
%% Inverse Quantization
ReconstructedImage=ReconstructedImage*quantizedvalue;
%% Wavelet Reconstruction
sX = size(ReconstructedImage);
cA1 = ReconstructedImage(1:(sX(1)/2), 1:(sX(1)/2));
cH1 = ReconstructedImage(1:(sX(1)/2), (sX(1)/2 + 1):sX(1));
cV1 = ReconstructedImage((sX(1)/2 + 1):sX(1), 1:(sX(1)/2));
cD1 = ReconstructedImage((sX(1)/2 + 1):sX(1), (sX(1)/2 + 1):sX(1));
ReconstructedImage = idwt2(cA1,cH1,cV1,cD1,'haar');
%% Visualize both Input and Reconstructed Images
subplot(1,2,1);imshow(InputImage);title('Input Image');
subplot(1,2,2);imshow(ReconstructedImage,[]);title('Reconstructed Image');
%% Calculating PSNR and MSE
InputImage=double(InputImage);
ReconstructedImage=double(ReconstructedImage);
n=size(InputImage);
M=n(1);
N=n(2);
MSE = sum(sum((InputImage-ReconstructedImage).^2))/(M*N);
PSNR = 10*log10(256*256/MSE);
disp('MSE');
disp(MSE);
disp('PSNR');
disp(PSNR);
disp('InputBitcost');
disp(InputBitcost);
disp('OutputBitcost');
disp(OutputBitcost);
