All-digital Holography and Application in Digital Image Hiding

摘要

It is presented here that the all-digital holography is applied to the digital image hiding. Computer Generated Hologram is generated and reconstructed by numerical method. The secret message and the host message are all still gray-images. The secret image is first transformed into a hologram (CGH), which is called holographic transform and then Arnold transform is performed. DCT is applied in the host image. Then the secret image is embedded into the DCT middle coefficients. The application of the holographic transform improves the transparency of the secret image; by controlling the parameter of the hologram the secrecy of the image is enhanced and add another key to have invisibility and certain robust.