Intensity image-embedded binary holograms

Past research has demonstrated that, by downsampling the source object scene in multiple directions, a binary Fresnel hologram can be generated to preserve favorable quality on the reconstructed image. In this paper, we will show that a binary hologram generated with such an approach is also insensitive to noise contamination. On this basis, we propose a method to embed an intensity image into the binary hologram. To prevent the embedded information from being tampered or retrieved with unauthorized means, scrambling is applied to relocate each pixel to a unique position in the binary hologram according to a random assignment that is only known with the availability of a descrambling key. Experimental results demonstrate that our proposed method is capable of embedding an intensity image that is one quarter the size of the binary hologram without causing observable degradation on the reconstructed image. In addition, the embedded image can be retrieved with acceptable quality even if the binary hologram is damaged and contaminated with noise.