Efficient coding of experimental holograms using speckle denoising
; Fonseca, E.
; Fiadeiro, PF
Signal Processing: Image Communication Vol. 96, Nº , pp. 116306 - 116306, May, 2021.
ISSN (print): 0923-5965
Journal Impact Factor: 2,209 (in 2014)
Digital Object Identifier: 10.1016/j.image.2021.116306
Lossy compression for Experimental Holograms (EH) and Computer-Generated Holograms (CGH) using standardized coding solutions is a highly efficient process provided that these solutions can be applied to the object plane. This compression efficiency reveals to be more relevant in CGH. Speckle noise mainly affects reconstructed EH, and to less extent reconstructed CGH. In the current work, the reduction of speckle noise of EH is proposed to improve the coding efficiency of the hologram compression scheme. The compression scheme defines a base layer where a 2D version of the object is coded with an image codec standard. When speckle noise reduction is performed before any compression, efficient compression is obtained for both CGH and EH. Since speckle noise reduction is performed only on amplitude data, without affecting the phase information of the reconstructed hologram, it is still possible to render 3D features such as depth map, multi-view or to recover holographic interference patterns for further 3D visualization.