updated comments + additional check cases

updated comments + additional check cases

main.m

@@ -8,25 +8,15 @@
 payload=randi([0,1],payload_length,1);
 
 %% Embedding for maximum contrast
-iteration_max=[];
-[rdh_image, ~, ~, ~,embedding_capacity_left]=mbp(image,payload,iteration_max,[]);
+iteration_max=1000; % default maximum iteration_max is 1000, you can increase it as much as you want, but it may take longer time
+max_contrast_bypass_mode=0; % 0 = embedes addtional synthetic bits after the specified payload has been embedded to maximize the contrast
+[rdh_image, ~, ~, ~,embedding_capacity_left]=mbp(image,payload,iteration_max,max_contrast_bypass_mode);
 if embedding_capacity_left < 0
-    disp('Failed embedding, increase iteration_max') % default maximum iteration_max is 300, you can increase it as much as you want, but it may take longer time
+    disp('Failed embedding, try increasing iteration_max') 
 else
     disp(['Can embed ' num2str(embedding_capacity_left) ' bits more (estimated)'])
 end
 
-%% Embedding only the payload => does not maximize the contrast
-max_contrast_bypass_mode=1;
-iteration_max=[];
-[rdh_image_non_max_contrast, ~, ~, ~,embedding_capacity_left_non_max_contrast]=mbp(image,payload,iteration_max,max_contrast_bypass_mode);
-if embedding_capacity_left_non_max_contrast < 0
-    disp('Failed embedding, increase iteration_max') % default maximum iteration_max is 300, you can increase it as much as you want, but it may take longer time
-else
-    disp(['Can embed ' num2str(embedding_capacity_left_non_max_contrast) ' bits more (estimated)'])
-end
-
-
 %% Recovery check for maximum contrast case
 [payload_rec, re_image] = mbp_recovery(rdh_image);
 if isequal(re_image,image)
@@ -41,6 +31,19 @@
     disp('Failed to recover the payload')
 end
 
+
+%% Embedding only the payload => does not maximize the contrast
+iteration_max=1000; % default maximum iteration_max is 1000, you can increase it as much as you want, but it may take longer time
+max_contrast_bypass_mode=1; %1=terminates after specified payload has been embedded, does not achieve maximum contrast
+[rdh_image_non_max_contrast, ~, ~, ~,embedding_capacity_left_non_max_contrast]=mbp(image,payload,iteration_max,max_contrast_bypass_mode);
+
+if embedding_capacity_left_non_max_contrast ~= -1
+    disp('Failed embedding, try increasing iteration_max') 
+else
+    disp(['Successfully embedded ' num2str(payload_length) ' bits. Cannot determine how many more bits can be embedded since max_contrast_bypass_mode was 1. To determine maximum number of bits embeddable (estimated), run with max_contrast_bypass_mode =0'])
+end
+
+
 %% Recovery check for when only the specified payload has been embedded => does not maximize the contrast
 [payload_rec_non_max_contrast, re_image_non_max_contrast] = mbp_recovery(rdh_image_non_max_contrast);
 if isequal(re_image_non_max_contrast,image)

mbp.m

@@ -1,18 +1,16 @@
 function [rdh_image, iteration_max, EC_list, LM_size_list, embedding_capacy_left]=mbp(image, actual_payload,iteration_max, max_contrast_bypass_mode)
 if isempty(iteration_max)
-        iteration_max = 300;
+        iteration_max = 1000;
 end
 if isempty(max_contrast_bypass_mode)
     max_contrast_bypass_mode = 0;
 end
+
 %Preprocess Payload (length appended)
 image_size=size(image);
 payload_length_max=2*ceil(log2(image_size(1)*image_size(2)+1));
 actual_payload=[de2bi(length(actual_payload),payload_length_max)'; actual_payload];
 
-
-rng(0);
-%image = image(5:end-5,5:end-5);
 image_size = size(image);
 
 P_s_list=zeros(1,iteration_max);
@@ -97,6 +95,7 @@
         else
             image_hor(image_hor < P_s & image_hor > P_c)=image_hor(image_hor < P_s & image_hor > P_c)+d; %LHS
         end
+
         %Embed P_s
         image_hor(image_hor==P_s & message_whole)=image_hor(image_hor==P_s & message_whole)+d;
 
@@ -110,6 +109,9 @@
         ref_image_hor(:,iteration_max+1:end) = [];
         payload_total=[payload_total; payload];
         embedding_capacy_left=length(payload_total)-length(actual_payload);
+        if max_contrast_bypass_mode ==1
+            embedding_capacy_left=-1;
+        end
         break
 
     else