I want to develop a steganography project with using exploiting modification direction method. I started to try and understand how the method works, but I have some questions about decryption.
I hid the secret image in a cover image larger than the secret image by 9 times. So when it comes to decryption I'm not going to use all of the pixels of the cover image: I only need to use those pixels used during encryption. But if the pixel count isn't provided before then how can I know how many pixels should be used to extract the secret image?
If I use all pixels of the cover image the resulting image's size doesn't match the original one and it is quite likely there will be flaws in the image.