U.S. perspective italic There is no rmended italic image size for a photo that is uploaded for copyright registration purposes. The maximum italic file size is 5 megabytes citation target s title Help Uploading your work index 1 unique_id AIDVX . The acceptable file s citation target s title Acceptable Files for Uploading in eCO index 2 unique_id eJAjY are .bmp (Bitmap Image) (AutoCAD Drawing) (Autodesk Design) .giff (Graphics Interchange Format) .jpeg .jfif (Joint Photographic Experts Group) (Portable Document Format) .pict (Picture File) (Portable Network Graphic) (Photoshop Document) (Microsoft Publisher) (Targa Graphic) .tiff (Tagged Image File Format) (Windows Metafile) I believe there is a reasonable argument for registering both the watermarked and the unwatermarked versions of a photo (more-direct proof of infringement whichever version was copied without permission) but I can appreciate that the copyright holder may not want to devote twice as much time energy and and money to copyright registration.