Camera unavoidable scene watermarks: A method for forcibly conveying information onto photographs

When a scene's image rights need to be protected e.g. a stage performance, it is valuable to use human imperceptible methods to forcibly add markers to a camera's perception of the scene regardless of the camera's precise location, focus distance, or shutter speed. This work expands upon extant methods for adding human imperceptible, camera perceptible markers to scenes but does so with the assumption that the photographer will take natural steps to avoid capturing the markers. The proposed method utilizes a combination of a traditional method of adding an image to the scene, and projections from the scene onto the camera's entrance pupil. This method is intended to function even when the target camera utilizes an IR filter and has a shutter speed 1/60 s. More interestingly, the combination of traditional images with projecting onto the camera allows this method to not be reliant upon knowledge of the camera's focus settings, or the precise location of the camera. It is, however, marred by numerous other requirements which make the method unreliable.