US Patent 11750853 Watermarking with phase shifting

Apparatus, devices, systems, methods, and articles of manufacture are disclosed for watermarking with phase shifting. An example watermark encoding apparatus includes memory, machine readable instructions, and processor circuitry to execute the instructions to select a plurality of frequencies for encoding a watermark symbol, apply a phase shift pattern to the plurality of frequencies, the phase shift pattern based on a phase reference, and embed in the plurality of frequencies the applied phase shift pattern in a media signal to encode the watermark symbol in the a media signal, and embed the phase reference into the media signal.