DWT_IDWT_Quant_Dequant_DONE

IMG = imread('pasi.jpg');
% RGB -> YCbCr
IMG2 = rgb2ycbcr(IMG);
[W,S,N] = size(IMG2);
Y1 = IMG2(1:1:W,1:1:S,1);
Cb1 = IMG2(1:1:W,1:1:S,2);
Cr1 = IMG2(1:1:W,1:1:S,3);
%QF
QF=50;
if QF<50
 qscale=floor(50/QF);
else
 qscale=2-(QF/50);
end
QX=round(qscale);
QUANTIZE = @(block_struct) round(block_struct./QX);
DEQUANTIZE = @(block_struct) round(block_struct.*QX);
% DWT IDWT
DWT = @(block_struct) dwt2(block_struct,'haar');
IDWT = @(block_struct) idwt2(block_struct,[],[],[],'haar');
IDCT=@idct2;
Y2 = blkproc(Y1,[8 8],DWT);
Cb2 = blkproc(Cb1,[8 8],DWT);
Cr2 = blkproc(Cr1,[8 8],DWT);
% Quantize
Y2 = blkproc(Y2,[8 8],QUANTIZE);
Cb2 = blkproc(Cb2,[8 8],QUANTIZE);
Cr2 = blkproc(Cr2,[8 8],QUANTIZE);
% Dequantize
Y2 = blkproc(Y2,[8 8],DEQUANTIZE);
Cb2 = blkproc(Cb2,[8 8],DEQUANTIZE);
Cr2 = blkproc(Cr2,[8 8],DEQUANTIZE);
% IDCT
Y2 = blkproc(Y2./255,[8 8],IDWT);
Cb2 = blkproc(Cb2./255,[8 8],IDWT);
Cr2 = blkproc(Cr2./255,[8 8],IDWT);
% YCbCr -> RGB
jpeg_result=ycbcr2rgb(cat(3,Y2,Cb2,Cr2));
% Save
imwrite(jpeg_result,'Test_pasiQF_50.jpg')