How return my image from binary to grayscale

I hide my image "mouse" in image " pigs". Firstly I convert the image "mouse" to binary in encryption code .secondly I return it from decryption code .Now I want to return it to gray-scale. how can help please.

encryption code

main = imread('mouse.tif');
cover = imread('pigs.tif');
main2= im2bw(main);

bitNo = 1;
steg = zeros(size(cover), 'uint8');

for i = 1:size(cover,1)
    for j = 1:size(cover,2)
       coverTmp  = dec2bin(cover(i,j), 8); 
       msgTmp   = dec2bin(main2(i,j)); 
       coverTmp(9-bitNo) = msgTmp;
       steg(i,j) = bin2dec(coverTmp);
    end
end
imwrite(steg,'S1.tif');

decryption code

stego = imread('S1.tif');

steg1 = zeros(size(stego));

for i = 1:size(stego,1)
    for j = 1:size(stego,2)
       mTmp  = dec2bin(stego(i,j), 8); 
       msTmp = mTmp(9-bitNo);
       steg1(i,j) = bin2dec (msTmp);
    end
end  
grayImage = 255*uint8(steg1);
figure, imshow(grayImage);

[Image Analyst]

You forgot to attach s1.tif, mouse.tif, and pigs.tif. If you want an bitplane watermarking demo, see my attached demo.

[hudof najeeb]

thank you it is very useful.

Answer 1

[John D'Errico]

If your image is at the end in binary form, so 0-1 only, then nothing can convert it back into a full grayscale, with additional information per pixel. You have thrown that information away. That information is lost forever. If you wanted to retain more information, then you needed to do a better job of storing the additional information before you lost it.

[snehal gaikwad]

if we have rescaled the binary image which gives area of interest from grayscale image then how we can convert binary image back to that input garyscaled image of same size (size of resized binary image)