to rejoin the separated roi and roni of a dicom image

i hav the code for separating a dicom image as ROI and RONI. pls help me to reverse the process.

%code for separating the ROI and RONI of a DCM file
clear all;
close all;

[RONI,MAP]=dicomread('189.dcm');
InputImg1 = uint8(255*mat2gray(RONI));
% Display the Image
figure,imshow(InputImg1,[]);title('Select the region of interest(ROI)');
% Get Inputs from Mouse,Select 4 Seed Points in Image
[Col Row]=ginput(4);
c =Col;
r =Row;
% Select polygonal region of interest
BinaryMask = roipoly(InputImg1,c,r);
%figure,imshow(BinaryMask,[]); title('Selected Region of Interest')
%Create Buffer for ROI
ROI=zeros(512,512);
%Create Buffer for NONROI
RONI=zeros(512,512);
for i=1:512
for j=1:512
if BinaryMask(i,j)==1
ROI(i,j)=InputImg1(i,j);
else
RONI(i,j)=InputImg1(i,j);
end
end
end

%Display ROI and Non ROI
figure,imshow(ROI,[]);title('ROI');
figure,imshow(RONI,[]);title('NON ROI');

Answer 1

[Walter Roberson]

Merged = RONI;
Merged(BinaryMask) = ROI;
figure,imshow(Merged,[]);title('Merged NON ROI and ROI');

[rolack KIKISSAGBE]

your code for reverse the separation of roi and roni dont work

[Walter Roberson]

Merged = RONI;
Merged(BinaryMask) = ROI(BinaryMask);
figure,imshow(Merged,[]);title('Merged NON ROI and ROI');

[rolack KIKISSAGBE]

Thank you so much. however, you can help me. I have an error in this code which allows to hide a text in an image and extract some. The output during extraction always gives unique characters 'ÿ' Can you help me?

this is the code for encode

% Clear the existing workspace 
clear all; 

% Clear the command window 
clc; 

% Read the input image 
input = imread('C:\Users\kenus\Downloads\Steg\12.png'); 

% Convert image to greyscale 
input=rgb2gray(input); 

% Resize the image to required size 
input=imresize(input, [512 512]); 

% Message to be embedded 
message='ok'; 

% Length of the message where each character is 8 bits 
len = length(message) * 8; 

% Get all the ASCII values of the characters of the message 
ascii_value = uint8(message); 

% Convert the decimal values to binary 
bin_message = transpose(dec2bin(ascii_value, 8)); 

% Get all the binary digits in separate row 
bin_message = bin_message(:); 

% Length of the binary message 
N = length(bin_message); 

% Converting the char array to numeric array 
bin_num_message=str2num(bin_message); 

% Initialize output as input 
output = input; 

% Get height and width for traversing through the image 
height = size(input, 1); 
width = size(input, 2); 

% Counter for number of embedded bits 
embed_counter = 1; 

% Traverse through the image 
for i = 1 : height 
	for j = 1 : width 
		
		% If more bits are remaining to embed 
		if(embed_counter <= len) 
			
			% Finding the Least Significant Bit of the current pixel 
			LSB = mod(double(input(i, j)), 2); 
			
			% Find whether the bit is same or needs to change 
			temp = double(xor(LSB, bin_num_message(embed_counter))); 
			
			% Updating the output to input + temp 
			output(i, j) = input(i, j)+temp; 
			
			% Increment the embed counter 
			embed_counter = embed_counter+1; 
		end
		
	end
end

% Write both the input and output images to local storage 
% Mention the path to a folder here. 
imwrite(input, 'C:\Users\kenus\Downloads\Steg\originalImage.png'); 
imwrite(output, 'C:\Users\kenus\Downloads\Steg\stegoImage.png'); 
filename = 'C:\Users\kenus\Downloads\Steg\output_img.xlsx'; 

xlswrite(filename, output); 

here is the code for extract

% Clear the existing workspace 
clear all; 

% Clear the command window 
clc; 

% Getting the input image 
filename = 'C:\Users\kenus\Downloads\Steg\output_img.xlsx'; 
input_image = xlsread(filename); 

% Get height and width for traversing through the image 
height = size(input_image, 1); 
width = size(input_image, 2); 

% Number of characters of the hidden text 
chars = 2; 

% Number of bits in the message 
message_length = chars * 8; 

% counter to keep track of number of bits extracted 
counter = 1; 

% Traverse through the image 
for i = 1 : height 
	for j = 1 : width 
		
		% If more bits remain to be extracted 
		if (counter <= message_length) 
			
			% Store the LSB of the pixel in extracted_bits 
			extracted_bits(counter, 1) = mod(double(input_image(i, j)), 2); 
			
			% Increment the counter 
			counter = counter + 1; 
		end
	end
end

% Powers of 2 to get the ASCII value from binary 
binValues = [ 128 64 32 16 8 4 2 1 ]; 

% Get all the bits in 8 columned table 
% Each row is the bits of the character 
% in the hidden text 
binMatrix = reshape(extracted_bits,8,(message_length/8)); 

% Convert the extracted bits to characters 
% by multiplying with powers of 2 
textString = char(binValues*binMatrix); 

% Print the hidden text 
disp(textString); 

thanks you

[Walter Roberson]

That does not have anything to do with the topic of this Question, and should have been posted in its own Question.

The code works for me.

I had to change filenames because I do not have the same directories. I also had to change away from xlswrite() because on my system xlswrite() cannot write .xlsx files.

I changed to use writematrix() and readmatrix(), which need R2019b or later.

Modified files are enclosed.

I did not have your 12.png so I used the standard file onion.png . Perhaps that made a difference.

[Tanjena Azim]

I am working on NROI based image watermarking. I have used Watershed segmentation in a x-ray image of a brain. But, now I am failing to separate the NROI from the ROI for further watermarking. Any simple code like foregroundValues, background values or anything can be used?? If anybody has a solution example reagrding this, please please help me.....I am stuck there and can't proceed further :(

[Walter Roberson]

I myself do not have much experience with that work. @Image Analyst might have suggestions.

[Tanjena Azim]

.@Walter Roberson Sir, thanks for ur prompt reply :)