According to the Copyright Act §39(1), you cannot receive damages if it can be shown that the it reasonable to believe that the defendant didn’t know copyright had been established. To avoid this problem, make it clear that your copyright has been established by adding © Person, Year to every image that you want protected. You can also add a notice to your web site indicating that all works created by you on this site are considered copyright unless otherwise stated. For extra safety, a description of key works can be registered with CIPO (Canadian Intellectual Property Office) for $60. You can also register a compilation of works (images in a collection) as a single entity for the same fee. For particularly valuable works, a lawyer can be retained for $400 to register the work with an affidavit certifying the image itself is clearly linked to the registration.