Case Comparison Between Direct Image Compression And Hologram Compression

Image compression means to encode a primary digital image in a secondary binary stream either to be stored in minimum bit-space or transmitted remotely. Starting from the "image" in the sense of a complex optical field as object for human vision and its corresponding hologram, the study presents the comparison between the genuine object and two of its copies obtained via two different sequences: one is consisting in compression-decompression of the hologram of the object followed by object retrieval, whilst the other is consisting in simply compressing-decompressing the object itself. Depending on the pathway, the compression algorithm uses spatial transforms (discrete wavelet DWT, discrete cosine DCT), or no transform at all. The performances of the two alternatives are discussed in terms of root-mean square distance (RMSD) for different quantization matrices (QM) and compression ratios (CR). The performances of hologram compression are approaching those of direct compression for visual images based on optimal JPEG techniques and might be an option for objects carrying information with no visual significance.