  Steganography is the art of hiding the fact that communication is taking
place, by hiding information in other information. Many different carrier file
formats can be used, but digital images are the most popular because of their
frequency on the Internet. For hiding secret information in images, there
exists a large variety of steganographic techniques some are more complex than
others and all of them have respective strong and weak points. Different
applications have different requirements of the steganography technique used.
For example, some applications may require absolute invisibility of the secret
information, while others require a larger secret message to be hidden. This
paper intends to give an overview of image steganography, its uses and
techniques. It also attempts to identify the requirements of a good
steganographic algorithm and briefly reflects on which steganographic
techniques are more suitable for which applications.
