Abstract: Provided is a computer-implemented video processing method. The method comprises receiving a stream of original images related to a video access event and creating a stream of output images corresponding to the original images. The output images include first images comprising a hidden digital forensic marker and second images comprising a visible digital forensic marker. The hidden marker and the visible marker each encode information related to the video access event. The stream of output images is output onto a network or caused to be displayed on a screen. The visible marker serves as a deterrent for distribution or recording, and if an attempt is made to remove it, the hidden marker remains in the image, allowing the information relevant to the video access event to be recovered. Also provided are a method of integrity detection for a stream of images containing markers, and a method of embedding a dynamic marker.