Writing Text to a new Text file from a Variable having Text

I am working with images. I have a variable d in which I stored text from a image. The value of variable d is coming right but when I am writing this variable to a new text file it is not coming right. This is the idea. please tell what I am doing wrong:

 d = char(I);
disp('Decrypted message is:');
disp(d);
fid = fopen('decr.txt', 'w');
fwrite(fid, d);
fclose(fid);

Answer 1

[Guillaume]

You may want to open your file with 'wt' instead if '|w|'. That will ensure that any end of line is properly formatted for your operating system (some OSes use '\n\r' for end of line, others just '\n' or '\r').

Use fprintf rather than fwrite to write to text files, fwrite is for writing to binary files:

fprintf(fid, '%s\n', d);

If you really want to use fwrite, you need to tell it you want to write characters not bytes:

fwrite(fid, d, 'char');

[GodGOD]

Ok Text is still Not retrieving when writing to a new file. I am attaching code file and text files please check what is wrong with the code.

why decr.text is not having text which is in d variable. Please Tell me

[Guillaume]

Well, it has the text in d. It's just that your d has been flattened to a 1*mn matrix.

As you should know, when you reshape an m*n matrix into a 1*(m*n) matrix, the elements are taken by column, hence the text that ends up in the file is first, the first column of d, then the 2nd, etc.

To fix that, just transpose d

fprintf(fid, '%s\n', d'); %or fwrite

It's better to be explicit about the flattening though, so I'd actually use:

fprintf(fid, '%s\n', reshape(d', 1, [])); %or fwrite

[GodGOD]

Great now text is retrieving. one last question Why there are numbers in last of some of lines in d????

[Guillaume]

The last character of each line is going to be the character of the value of the last pixel of each row of your original image, since your image is 128 columns and you only replace the first 127 columns with your text.

It looks like your doing some sort of steganography. If that is the case, your algorithm doesn't look right to me. Effectively, you're completely replacing the pixels of the original image with the ASCII values of your text. If you need help with that, however, you need to start a new question. It is a completely different topic to this one.

[GodGOD]

ok thanks alot. yes algo is weird. I am trying to do steganography. I am a beginner so that why algo is not right. I am trying to clear my concepts. You helped me alot thank You