Image Steganography

Question

I\'m working on Steganography application. I need to hide a message inside an image file and secure it with a password, with not much difference in the file size. I am using

Answer 1

This heavily depends on the way the particular image format works. You'll need to dive into the internals of the format you want to use.

For JPEG, you could fiddle with the last bits of the DCT coefficients for each block.

For palette-based files (GIFs, and some PNGs), you could add extra colours to the palette that look identical to the existing ones, and encode information based on which one you use.