Copyright - Wikipedia, the free encyclopediaIn all countries where the Berne Convention standards apply, copyright is automatic, and need not be obtained through official registration with any government office. Once an idea has been reduced to tangible form, for example by securing it in a fixed medium (such as a drawing, sheet music, photograph, a videotape, or a computer file), the copyright holder is entitled to enforce his or her exclusive rights. However, while registration isn't needed to exercise copyright, in jurisdictions where the laws provide for registration, it serves as prima facie evidence of a valid copyright and enables the copyright holder to seek statutory damages and attorney's fees. (In the USA, registering after an infringement only enables one to receive actual damages and lost profits.)
The phrase "exclusive right" means that only the copyright holder is free to exercise those rights, and others are prohibited from using the work without the holder's permission.
Have a look at Tineye - that's very useful to see if someone has used your image elsewhere. I have successfully taken action a couple of times to protect my copyright.