hiding bits in image

[stegano]

I hv an array of boolean and i want to store it in some position of an image.
Anybody can help me???
Any code example????

[Skiller]

There are many ways to do it but almost all are highly dependent on the image format.

The easiest and most compatible way is to store the data in the last bit of each value of each color channel as well as an integer specifying how much data there is. All this needs is a lossless image format like BMP or PNG.

Some file formats will allow you to just stuff whatever data you want at the end of the file, though it works best with lossy image formats as the difference in file size is less noticeable. However you can't always guarantee that programs reading the image as an image will ignore the additional data safely.

A few file formats actually support custom data chunks where you can store whatever you want if you follow a sort of template for storing your data (usually some identifier and the size of the data followed by the actual data).

It's all pretty basic stuff but you really need to research the image format to find out what will work with what and how.


Edit: Be aware that some of these methods have been used to hide viruses and virus scanners could detect the data as being a potential virus even if it isn't.