Fig. 1. Diffraction pattern at 100 mm. (a) Result of traditional angular spectrum diffraction; (b) result of band-limited angular spectrum diffraction

Fig. 2. Optimization scheme framework

Fig. 3. Principle diagram of mask extension for holographic display viewing angle of spatial light modulator. (a) Phase mask extension for holographic display viewing angle optical system structure; (b) schematic of resolution difference matching

Fig. 4. Band-limited angular spectrum diffraction GS optimization algorithm based on phase mask extension for holographic display viewing angle method

Fig. 5. Reconstruction using time-averaging method

Fig. 6. Layered hologram computation with additional random phase mask for three-dimensional holography

Fig. 7. Improved GS iterative optimization process

Fig. 8. Parallel computation flow

Fig. 9. Structure of transfer function lookup table for band-limited angular spectrum

Fig. 10. Hologram and its reconstruction results. (a) Original image; (b) hologram computed with traditional angular spectrum diffraction; (c) reconstruction result of traditional angular spectrum diffraction hologram; (d) hologram computed with band-limited angular spectrum diffraction; (e) reconstruction result of band-limited angular spectrum diffraction hologram; (f) hologram computed with band-limited angular spectrum diffraction GS iteration for 20 times; (g) reconstruction result of band-limited angular spectrum diffraction GS iteration for 20 times

Fig. 11. Comparison of results of reconstruction using traditional angular spectrum diffraction GS and band-limited angular spectrum diffraction GS with time-averaging method respectively. (a) Original image; (b)‒(d) reconstruction images using traditional angular spectrum diffraction GS optimization for iteration 20 times combined with time-averaging method; (e)‒(g) reconstruction images using band-limited angular spectrum diffraction GS optimization for iteration 20 times combined with time-averaging method

Fig. 12. Objective evaluation metrics for reconstruction results. (a) Speckle contrast; (b) SSIM; (c) PSNR

Fig. 13. Final reconstruction results. (a) Optimized final result from Ref. [10]; (b) optimized result of method in this paper (reconstruction of 20 holograms)

Fig. 14. Intensity and depth images of three-dimensional object. (a) Intensity image; (b) depth image

Fig. 15. Holograms with or without GS optimization and reconstruction images with holograms participating in focusing and head reconstruction. (a) Three-dimensional phase hologram without GS optimization; (b) three-dimensional phase hologram with GS optimization iteration for 40 times; (c) reconstruction image with 1 hologram without GS optimization participating in focusing and head reconstruction; (d) reconstruction image with 1 hologram with GS optimization iteration for 40 times participating in focusing and head reconstruction; (e) reconstruction image with 20 holograms without GS optimization participating in focusing and head reconstruction; (f) reconstruction image with 20 holograms with GS optimization iteration for 40 times participating in focusing and head reconstruction

Fig. 16. Local enlargement of three-dimensional reconstructed images. (a) Without GS optimization; (b) GS iteration for 40 times

Fig. 17. Before and after improvement, holograms and reconstruction results computed with band-limited angular spectrum diffraction GS iteration optimization. (a) Original image; (b) hologram computed with traditional angular spectrum diffraction; (c) reconstruction result of traditional angular spectrum diffraction hologram; (d) hologram computed with band-limited angular spectrum diffraction GS iteration for 20 times; (e) reconstruction result of band-limited angular spectrum diffraction GS iteration for 20 times; (f) improved hologram computed with band-limited angular spectrum diffraction GS iteration for 20 times; (g) reconstruction result of improved hologram computed with band-limited angular spectrum diffraction GS iteration for 20 times

Fig. 18. Holograms and reconstruction images computed with parallel computation with multiple streams and lookup table. (a) Hologram computed sequentially with 40 iterations; (b) hologram computed in parallel with 40 iterations; (c) reconstruction image of a single hologram computed sequentially; (d) reconstruction image of a single hologram computed in parallel; (e) reconstruction image of 20 holograms computed sequentially; (f) reconstruction image of 20 holograms computed in parallel; (g) local enlargement of reconstruction image with 20 holograms computed sequentially; (h) local enlargement of reconstruction image with 20 holograms computed in parallel