Fig. 1. Images used in simulation. (a) Amplitude sample pattern and scanning route; (b) complex amplitude of converging probe; (c) a diffraction pattern

Fig. 2. Reconstruction results under different dynamic ranges. (a) PSNR curves of reconstruction images; (b) MSE curves of diffraction patterns; (c) original image; (d) reconstruction image of single exposure with 8-bit dynamic range; (e) reconstruction image of conventional HDR with 8-bit dynamic range; (f) reconstruction image of ML-HDR with 8-bit dynamic range

Fig. 3. Reconstruction results of diffraction patterns with different SNR. (a) PSNR curves of diffraction patterns; (b) MSE curves of diffraction patterns; (c) original image; (d) reconstruction image of single exposure with SNR of 24 dB; (e) reconstruction image of conventional HDR with SNR of 24 dB; (f) reconstruction image of ML-HDR with SNR of 24 dB

Fig. 4. Experimental system setup

Fig. 5. Diffraction patterns (logarithm after binning). (a)‒(g) Single-exposure diffraction patterns; (h) diffraction pattern synthesized by ML-HDR method

Fig. 6. Complex amplitude of reconstruction sample and probe (brightness represents amplitude, color represents phase). (a) 8-bit single exposure; (b) 8-bit conventional HDR; (c) 8-bit ML-HDR; (d) 16-bit single exposure

Fig. 7. Reconstruction results with 16 bit readout mode. (a) Complex amplitude of sample under single exposure; (b) complex amplitude of sample under conventional HDR; (c) complex amplitude of sample under ML-HDR; (d) outlines of the 9th group elements