Test_Quantiser.asv

% Quantiser Test app
% ------------------------------
clc;clear

%=====================================================================
%       TEST - SCRIPT PARAMETERS
%=====================================================================

img = imread('lena512.bmp');
imshow(img);

%img = imread('photocopy.bmp');
%imshow(img);

img = double(img)-128;
[m,n] = size(img);
b = 8;
speed  = 1;     % 0-simple dct, 1-fast dct
q_type = 'NL';  % NL = Non-Linear, L=Linear 

%=====================================================================
%       E N C O D E R
%=====================================================================

% split the input larger matrix into smaller 8x8 blocks
split_img = mat2cell(img, b*ones(m/b,1), b*ones(1,n/b));

% perform DCT->Quantisation->Inverse-Quantisation->IDCT for each block
for i = 1:length(split_img)
    for j = 1:length(split_img)

        % --------------- 2D-DCT ---------------------------------------------
        % perform DCT - Encoder side
        enc_dct_block = dct_2_8x8(split_img{i,j},b,speed);      % output is a array of cells


        % --------------- Quantisation ---------------------------------------
        if (q_type == 'NL')
            enc_q_block =  NL_Quantizer(enc_dct_block,50,0);        
        elseif(q_type == 'L')
            enc_q_block =  L_Quantizer(enc_dct_block,0);    
        else
            error('unknown q_type');
        end


    %=====================================================================
    %       D E C O D E R
    %=====================================================================

        % --------------- Inverse - Quantisation------------------------------
        if (q_type == 'NL')
            dec_q_block =  NL_Quantizer(enc_q_block,50,1);         
        elseif(q_type == 'L')
            dec_q_block = L_Quantizer(enc_q_block{j},0);    
        else
            error('unknown q_type');
        end

    % --------------- 2D - Inverse - DCT ---------------------------------

        dec_idct_block = idct_2_8x8(dec_q_block{j},b, speed);    
        reconstructed_cell{i,j} = dec_idct_block;

    end
end
reconstructed_img = cell2mat(reconstructed_cell);     % output is a matrix

% add back the 128, and convert to uint8
reconstructed_img = reconstructed_img + 128;
reconstructed_img = uint8(reconstructed_img);

% display picture
figure;imshow(reconstructed_img);