Digital Image Steganography

The word digital image describes a image file that can be stored electronically, in contrast to such a file in another medium, such as a photograph printed on photo paper. 

The term steganography comes from the Greek words meaning “to cover tightly” and “writing.” It refers to the practice or art of concealing a message in any medium. Digital image steganography refers to concealing a message in a digital image.

Some Digital Image Steganography tools can be found on:

http://lifehacker.com/230915/geek-to-live--hide-data-in-files-with-easy-steganography-tools

One is "Hide in Windows" (screenshot below)

Another, "Pict Encrypt" for Mac's (screenshot below)

http://i.kinja-img.com/gawker-media/image/upload/18s02ohz1ghckpng.png

Sources:

http://www.wisegeek.com/what-is-digital-steganography.htm

https://en.wikipedia.org/wiki/Steganography

http://lifehacker.com/230915/geek-to-live--hide-data-in-files-with-easy-steganography-tools