all in ENG

#5

Main.m

@@ -8,7 +8,7 @@
 % Unmarked image has to be grayscale. If a color image is selected,  
 % it is coverted into grayscale image.
 
-global K block_dim Level faktor Vs Ss vis_wmarka sir_wmarka
+global K block_dim Level factor Vs Ss hdim_wmark wdim_wmark
 % TODO: Get rid of globals
 output_folder = 'output\\';
 step = 0;
@@ -43,13 +43,13 @@
             % Enter intensity/grayscale image
         end
         figure(1), imshow(Unmarked_image), title('Unmarked image')
-        [Image, Vs, Ss] = podes_slike(Unmarked_image);
-        faktor = norm_faktor(Image);
-        Image = double(Image)/faktor;
-        % Dimenzije watermarka
-        vis_wmarka = Vs/block_dim;
-        sir_wmarka = Ss/block_dim;
-        vel_wmarka = vis_wmarka * sir_wmarka;
+        [Image, Vs, Ss] = adj_image(Unmarked_image, block_dim);
+        factor = norm_factor(Image);
+        Image = double(Image)/factor;
+        % Watermark dimensions
+        hdim_wmark = Vs/block_dim;
+        wdim_wmark = Ss/block_dim;
+        hw_wmark = hdim_wmark * wdim_wmark;
     end
 
     % 2. Read watermark (binary image with pixels 0 or 1) ---------------------------------
@@ -90,21 +90,21 @@
         % MATLAB PSS generator is set to init state def by the key 
         rng(key);
         % PSS Permute the watermark
-        a1 = randperm(vel_wmarka);
+        a1 = randperm(hw_wmark);
         clear key; % delete key
-        a2 = reshape(a1, vis_wmarka, sir_wmarka);
+        a2 = reshape(a1, hdim_wmark, wdim_wmark);
         skrembl_wmark = watermark(a2);
         skrembl_wmark1 = (skrembl_wmark - 0.5)/0.5; % -1 i 1
         % skrembl_wmark1 is type double
         if method == 1
-            Marked_image = ugradnja_DCT(Image, skrembl_wmark1);
+            Marked_image = embed_DCT(Image, skrembl_wmark1, block_dim, K);
         elseif method == 2
-            Marked_image = ugradnja_DWT(Image, skrembl_wmark1);
+            Marked_image = embed_DWT(Image, skrembl_wmark1, Level, K);
         else
             error('\n Error. Unsupported method.');
         end
         figure(5), imshow(Marked_image), title('Marked image')
-        Marked_image_uint8 = uint8(Marked_image * faktor);
+        Marked_image_uint8 = uint8(Marked_image * factor);
         imwrite(Marked_image_uint8, 'output\\Marked_image.tif');
     end
 
@@ -122,11 +122,11 @@
                 %generates images that start with: JPEG_Mkd_img_
             end
             if k == 2
-                attack = brightness(Marked_image, output_folder);
+                attack = brightness(Marked_image, output_folder, factor);
                 %generates images that start with: Bright_Mkd_img_
             end
             if k == 3
-                attack = contrast(Marked_image, output_folder);
+                attack = contrast(Marked_image, output_folder, factor);
                 %generates images that start with: Mcon_Mkd_img_
                 %generates images that start with: Hcon_Mkd_img_
             end
@@ -156,8 +156,8 @@
             disp('Image dimensions have to be MxN pixels.');
             Marked_image = rgb2gray(Marked_image); % convert to grayscale
         end
-        faktor = norm_faktor(Marked_image);
-        Marked_image = double(Marked_image)/faktor;
+        factor = norm_factor(Marked_image);
+        Marked_image = double(Marked_image)/factor;
         % Dimensions of unmarked and marked image are the same.
         figure(6),imshow(Marked_image), title('Marked image (read)')
     end
@@ -169,13 +169,13 @@
         %key = input('\n Enter the password:   ');
         rng(key);
         % Undo the permutation of the watermark.
-        b1 = randperm(vel_wmarka);
+        b1 = randperm(hw_wmark);
         clear key; % delete key
-        b2 = reshape(b1, vis_wmarka, sir_wmarka);
+        b2 = reshape(b1, hdim_wmark, wdim_wmark);
         if method == 1
-            recovered_watermark = izdvajanje_DCT(Image, Marked_image, b2);
+            recovered_watermark = extract_DCT(Image, Marked_image, b2, block_dim, hdim_wmark, wdim_wmark);
         elseif method == 2
-            recovered_watermark = izdvajanje_DWT(Image, Marked_image, b2);
+            recovered_watermark = extract_DWT(Image, Marked_image, b2, Level, factor, hdim_wmark, wdim_wmark);
         else
             error('\n Error. Unsupported method.');
         end
@@ -191,9 +191,8 @@
         error = abs(recovered_watermark - watermark);
         br_pogr_bita = sum(sum(error));
         fprintf('\n Num of bit errors in detected watermark %i   ', br_pogr_bita)
-        procenat_pogr_bita = (br_pogr_bita/vel_wmarka)*100;
-        fprintf('\n BER [%%] for detected watermark %f  \n',...
-            procenat_pogr_bita)
+        procenat_pogr_bita = (br_pogr_bita/hw_wmark)*100;
+        fprintf('\n BER [%%] for detected watermark %f  \n', procenat_pogr_bita)
         disp('*******************************************************')
     end
     %    THE END  -----------------------------------------------------

adj_image.m

@@ -0,0 +1,19 @@
+function [Image, Vs, Ss] = adj_image(orig_Image, block_dim)
+% Podesavanje dimenzija slike (zero padding)
+% Image dimensions
+Vor = size(orig_Image, 1); % h
+Sor = size(orig_Image, 2); % w
+remainder1 = mod(Vor, block_dim);
+remainder2 = mod(Sor, block_dim);
+if (remainder1 ~= 0) || (remainder2 ~= 0)
+    Image = padarray(orig_Image, [remainder1, remainder2], 0, 'post');
+    % Image dimensions
+    Vs = size(Image, 1);
+    Ss = size(Image, 2);
+    fprintf('\n Dimenzije slike su podesene na: %ix%i.', Vs, Ss);
+else
+    Image = orig_Image;
+    % Image dimensions
+    Vs = size(Image, 1);
+    Ss = size(Image, 2);
+end

adj_wmark.m

@@ -1,34 +1,34 @@
-function zig = adj_wmark(orig_zig)
-global vis_ziga sir_ziga
-% Dimenzije originalnog ziga
-        Vz = size(orig_zig,1); % visina
-        Sz = size(orig_zig,2); % sirina
-% Podesavanje dimenzija ziga
-        zig1 = []; % inicijalizacija
-        if Vz < vis_ziga
-            n = floor(vis_ziga/Vz);
+function wmark = adj_wmark(w)
+global hdim_wmark wdim_wmark
+% Dim of original wmark
+        Vz = size(w,1); % h
+        Sz = size(w,2); % w
+% Adjust wmark dimensions
+        wmark1 = []; % init
+        if Vz < hdim_wmark
+            n = floor(hdim_wmark/Vz);
             for i = 1:n
-                zig1 = [zig1; orig_zig]; % zig se ponavlja po vertikali
+                wmark1 = [wmark1; w]; % repeat verticaly
             end
-            dopuna = orig_zig(1:mod(vis_ziga,Vz), :);
-            zig1 = [zig1; dopuna];
+            filler = w(1:mod(hdim_wmark,Vz), :);
+            wmark1 = [wmark1; filler];
         else
-            zig1 = orig_zig(1:vis_ziga, :); % odsecanje
+            wmark1 = w(1:hdim_wmark, :); % crop
         end
-        zig2 = []; % inicijalizacija
-        if Sz < sir_ziga
-            m = floor(sir_ziga/Sz);
+        wmark2 = []; % init
+        if Sz < wdim_wmark
+            m = floor(wdim_wmark/Sz);
             for j = 1:m
-                zig2 = [zig2, zig1]; % zig se ponavlja po horizontali
+                wmark2 = [wmark2, wmark1]; % repeat horizontaly
             end
-            dopuna = zig1(:, 1:mod(sir_ziga,Sz));
-            zig2 = [zig2, dopuna]; 
+            filler = wmark1(:, 1:mod(wdim_wmark,Sz));
+            wmark2 = [wmark2, filler]; 
         else
-            zig2 = zig1(:, 1:sir_ziga); % odsecanje
+            wmark2 = wmark1(:, 1:wdim_wmark); % crop
         end
-        zig = zig2;
-        if (Vz ~= vis_ziga) || (Sz ~= sir_ziga)
-            fprintf('\n Dimenzije ziga su podesene na: %ix%i.', ...
-                vis_ziga, sir_ziga);
-            imwrite(uint8(zig),'zig.bmp');
+        wmark = wmark2;
+        if ((Vz ~= hdim_wmark) || (Sz ~= wdim_wmark))
+            fprintf('\n Watermark dimensions are set to: %ix%i.', ...
+                hdim_wmark, wdim_wmark);
+            imwrite(uint8(wmark),'w.bmp');
         end  

brightness.m

@@ -1,5 +1,4 @@
-function attack = brightness(Marked_image, folder)
-global faktor
+function attack = brightness(Marked_image, folder, factor)
 %-------------------------------------------------------------------------
 % Modify brightness
 b = [0.1 0.2 0.3 0.4 0.5];
@@ -9,15 +8,15 @@
     iznad1 = find(osv_slika > 1);
     osv_slika(iznad1) = ones(size(iznad1));
     path = strcat(folder, ['Bright_Mkd_img_',num2str(b(i)),'.tif']);
-    imwrite(uint8(osv_slika * faktor),path);
+    imwrite(uint8(osv_slika * factor),path);
 end
 
 for i = 1:length(b)
     osv_slika = Marked_image - b(i);
     ispod1 = find(osv_slika < 0);
     osv_slika(ispod1) = zeros(size(ispod1));
     path = strcat(folder, ['Bright_Mkd_img_-',num2str(b(i)),'.tif']);
-    imwrite(uint8(osv_slika * faktor), path);
+    imwrite(uint8(osv_slika * factor), path);
 end
 
 attack = 'An attack by brightness change.';

contrast.m

@@ -1,21 +1,20 @@
-function attack = contrast(Marked_image, folder)
-global faktor
+function attack = contrast(Marked_image, folder, factor)
 %-------------------------------------------------------------------------
 % Modify contrast
 c = [0.5 0.6 0.7 0.9 1.1 1.4 1.5 1.6 1.7 1.8];
 
 for i = 1:length(c)
     kon_slika1 = c(i)* Marked_image;
     path = strcat(folder, ['Mcon_Mkd_img_',num2str(c(i)),'.tif']);
-    imwrite(uint8(kon_slika1 * faktor),path);
+    imwrite(uint8(kon_slika1 * factor),path);
 end
 
 bin = [8 16 32 64 96 128 160 192 224 240];
 
 for i = 1:length(bin)
     h_kon_slika = histeq(Marked_image, bin(i));
     path = strcat(folder, ['Hcon_Mkd_img_',num2str(c(i)),'.tif']);
-    imwrite(uint8(h_kon_slika * faktor),path);
+    imwrite(uint8(h_kon_slika * factor),path);
 end
 
 attack = 'An attack by contrast change.';

embed_DCT.m

@@ -0,0 +1,30 @@
+function Marked_Image_DCT = embed_DCT(Image, skrembl_zig1, dim_bloka, K)
+% Generate Marked_Image_DCT 
+global Vs Ss
+% Middle DCT coeffs range is selected for watermarking
+y = 1; n = 1; v = 1; m = 1; d = 0; x = 0;
+srednji = [  0, 0, y, n, v, m, d, x;    
+             0, y, n, v, m, d, x, 0;
+             y, n, v, m, d, x, 0, 0;
+             n, v, m, d, x, 0, 0, 0;
+             v, m, d, x, 0, 0, 0, 0;
+             m, d, x, 0, 0, 0, 0, 0;
+             d, x, 0, 0, 0, 0, 0, 0;
+             x, 0, 0, 0, 0, 0, 0, 0  ];
+Marked_Image_DCT = zeros(size(Image)); % init
+T = dctmtx(dim_bloka);
+z1 = 0; % init
+for s1 = 1: dim_bloka: Vs
+    z1 = z1 + 1;
+    z2 = 0; % init
+    for s2 = 1: dim_bloka: Ss
+        z2 = z2 + 1;
+        indx1 = s1: s1 + dim_bloka - 1;
+        indx2 = s2: s2 + dim_bloka - 1;
+        block = Image(indx1, indx2);
+        DCT_block = T * block * T'; % output is double type
+        beleg = K/100 * skrembl_zig1(z1, z2); % skrembl_zig1(z1, z2) is 1 or -1
+        Zig_DCT_blok = DCT_block + (abs(DCT_block)*beleg).*srednji;
+        Marked_Image_DCT(indx1, indx2) = T' * Zig_DCT_blok * T; % output is double type
+    end
+end

ugradnja_DWT.m → embed_DWT.m

@@ -1,33 +1,32 @@
-function Marked_image = ugradnja_DWT(Image, skrembl_zig1)
-% Generisanje slike oznacene koriscenjem Wavelet transformacije-----------
-global Level K
-% Level = 3
-%-------------------------------------------------------------------------
-[Image_DWT, bookie] = wavedec2(Image, Level, 'haar');
-Marked_Image_DWT = Image_DWT;  % init
-%-------------------------------------------------------------------------
-horiz_detalji3 = wavecopy('h', Image_DWT, bookie, Level);
-vert_detalji3 = wavecopy('v', Image_DWT, bookie, Level);
-dijag_detalji3 = wavecopy('d', Image_DWT, bookie, Level);
-zig_horiz_detalji3 = horiz_detalji3 + K/2/100 * abs(horiz_detalji3).*skrembl_zig1;
-zig_vert_detalji3 = vert_detalji3 + K/2/100 * abs(vert_detalji3) .* skrembl_zig1;
-zig_dijag_detalji3 = dijag_detalji3 + K/2/100 * abs(dijag_detalji3) .* skrembl_zig1;
-%-------------------------------------------------------------------------
-Marked_Image_DWT = wavepaste('h', Marked_Image_DWT, bookie, Level, zig_horiz_detalji3);
-Marked_Image_DWT = wavepaste('v', Marked_Image_DWT, bookie, Level, zig_vert_detalji3);
-Marked_Image_DWT = wavepaste('d', Marked_Image_DWT, bookie, Level, zig_dijag_detalji3);
-%-------------------------------------------------------------------------
-hor_detailes_2 = wavecopy('h', Image_DWT, bookie, Level-1);
-ver_detailes_2 = wavecopy('v', Image_DWT, bookie, Level-1);
-dijag_detalji2 = wavecopy('d', Image_DWT, bookie, Level-1);
-skrembl_zig2 = repmat(skrembl_zig1, Level - 1);
-
-mkd_hor_detailes_2 = hor_detailes_2 + 2*K/100 * abs(hor_detailes_2).*skrembl_zig2;
-mkd_ver_detailes_2 = ver_detailes_2 + 2*K/100 * abs(ver_detailes_2) .* skrembl_zig2;
-zig_dijag_detalji2 = dijag_detalji2 + 2*K/100 * abs(dijag_detalji2) .* skrembl_zig2;
-%-------------------------------------------------------------------------
-Marked_Image_DWT = wavepaste('h', Marked_Image_DWT, bookie, Level-1, mkd_hor_detailes_2);
-Marked_Image_DWT = wavepaste('v', Marked_Image_DWT, bookie, Level-1, mkd_ver_detailes_2);
-Marked_Image_DWT = wavepaste('d', Marked_Image_DWT, bookie, Level-1, zig_dijag_detalji2);
-%-------------------------------------------------------------------------
+function Marked_image = embed_DWT(Image, skrembl_zig1, Level, K)
+% Generate Marked_Image_DWT
+% Level = 3
+%-------------------------------------------------------------------------
+[Image_DWT, bookie] = wavedec2(Image, Level, 'haar');
+Marked_Image_DWT = Image_DWT;  % init
+%-------------------------------------------------------------------------
+horiz_detalji3 = wavecopy('h', Image_DWT, bookie, Level);
+vert_detalji3 = wavecopy('v', Image_DWT, bookie, Level);
+dijag_detalji3 = wavecopy('d', Image_DWT, bookie, Level);
+zig_horiz_detalji3 = horiz_detalji3 + K/2/100 * abs(horiz_detalji3).*skrembl_zig1;
+zig_vert_detalji3 = vert_detalji3 + K/2/100 * abs(vert_detalji3) .* skrembl_zig1;
+zig_dijag_detalji3 = dijag_detalji3 + K/2/100 * abs(dijag_detalji3) .* skrembl_zig1;
+%-------------------------------------------------------------------------
+Marked_Image_DWT = wavepaste('h', Marked_Image_DWT, bookie, Level, zig_horiz_detalji3);
+Marked_Image_DWT = wavepaste('v', Marked_Image_DWT, bookie, Level, zig_vert_detalji3);
+Marked_Image_DWT = wavepaste('d', Marked_Image_DWT, bookie, Level, zig_dijag_detalji3);
+%-------------------------------------------------------------------------
+hor_detailes_2 = wavecopy('h', Image_DWT, bookie, Level-1);
+ver_detailes_2 = wavecopy('v', Image_DWT, bookie, Level-1);
+dijag_detalji2 = wavecopy('d', Image_DWT, bookie, Level-1);
+skrembl_zig2 = repmat(skrembl_zig1, Level - 1);
+
+mkd_hor_detailes_2 = hor_detailes_2 + 2*K/100 * abs(hor_detailes_2).*skrembl_zig2;
+mkd_ver_detailes_2 = ver_detailes_2 + 2*K/100 * abs(ver_detailes_2) .* skrembl_zig2;
+zig_dijag_detalji2 = dijag_detalji2 + 2*K/100 * abs(dijag_detalji2) .* skrembl_zig2;
+%-------------------------------------------------------------------------
+Marked_Image_DWT = wavepaste('h', Marked_Image_DWT, bookie, Level-1, mkd_hor_detailes_2);
+Marked_Image_DWT = wavepaste('v', Marked_Image_DWT, bookie, Level-1, mkd_ver_detailes_2);
+Marked_Image_DWT = wavepaste('d', Marked_Image_DWT, bookie, Level-1, zig_dijag_detalji2);
+%-------------------------------------------------------------------------
 Marked_image = waverec2(Marked_Image_DWT, bookie, 'haar');

extract_DCT.m

@@ -0,0 +1,37 @@
+function rec_wmark= extract_DCT(Image, Marked_image, b2, block_dim, hdim_wmark, wdim_wmark)
+% Reconstruct wmark
+global Vs Ss
+%-------------------------------------------------------------------------
+y = 1; n = 1; v = 1; m = 1; d = 0; x = 0;
+range = [  0, 0, y, n, v, m, d, x;    
+             0, y, n, v, m, d, x, 0;
+             y, n, v, m, d, x, 0, 0;
+             n, v, m, d, x, 0, 0, 0;
+             v, m, d, x, 0, 0, 0, 0;
+             m, d, x, 0, 0, 0, 0, 0;
+             d, x, 0, 0, 0, 0, 0, 0;
+             x, 0, 0, 0, 0, 0, 0, 0  ];
+skrembl_zig = zeros(hdim_wmark,wdim_wmark); % init
+T = dctmtx(block_dim);
+z1 = 0; % init
+for s1 = 1: block_dim: Vs
+    z1 = z1 + 1;
+    z2 = 0; % init
+    for s2 = 1: block_dim: Ss
+        z2 = z2 + 1;
+        indeks1 = s1: s1 + block_dim - 1;
+        indeks2 = s2: s2 + block_dim - 1;
+        block = Image(indeks1, indeks2);
+        mkd_block = Marked_image(indeks1, indeks2);
+        DCT_blok = T * block * T';   % double
+        DCT_ozn_blok = T * mkd_block * T';   % double
+        B = (DCT_ozn_blok - DCT_blok) .* range;
+        if sum(sum(B)) > 0
+            skrembl_zig(z1, z2)= 1;
+        else
+            skrembl_zig(z1, z2)= 0;
+        end
+    end
+end
+rec_wmark = skrembl_zig;  % init
+rec_wmark(b2) = skrembl_zig;