How to save image after encryption?

I have code for encrypt an image, then ineed to save image after encryption to use it in another seperate code .

which command is prefere, imsave, imwrite? I try to use both but the saved image can't be showed correctly when i used imshow command.

[Jan]

What does "encrypt an image" mean? A file containing in image or the RGB data? What does "can't be showed correctly" mean? Of course an encrypted image does not look "correct".

[Arshub]

@Jan i mean : I have an image say 'lena.png ' if i read this image then shuffle the image, we get a new image after shuffle. I need save the new image in a new name say 'lena2.png'.

may be i need the new image 'lena2.png' in anther program to reshuffle the 'lena2.png' to get the original image lena.png '.

[Wajid]

imwrite(Lena2,'Lena2.png');

Answer 1

[Walter Roberson]

My suspicion would be that your original image is uint8 and that when you did the encryption, you did not make sure to create uint8 . Perhaps your results are all integers 0 to 255, but I suspect that class() of them is double() .

If your encrypted image is double() but only uses integers 0 to 255, then uint8() it.

If your encrypted image is double() but has some entries that are not integers 0 to 255, then you might have a problem.

[Arshub]

yes, may image after permutation in extention double and pixel values between 0 to 255.

but when i save them in png extention, all pixels become 255.

[Walter Roberson]

Either be more careful in doing the permutation to retain the original data type, or else take uint8() of the permutation.

Answer 2

[Image Analyst]

Unless your encryption produced another uint8 or uint16 image, you're probably best just saving it as a binary file with a .bin or .dat extension since no standard program will be able to read it and decrypt it successfully if you save as a .PNG extension - it will just confuse them and they'll throw an error. Something like (untested):

fid = fopen('encryptedImage.bin', 'wb');
fprintf(fid, '%c', yourImage);
fclose(fid);