Fig. 1. Experimental setup of quantum projection imaging. SCPL represents the supercontinuum pulsed laser. A filter is used to select out the beam wavelength of 660 nm. NDF is the neutral density filter. L is a collective lens. DMD is the digital micromirror device. SPAD is the single-photon avalanche detector. TCSPC is the module of time-correlated single-photon counting. PC is a computer.

Fig. 2. Photon probability distributions of the bucket signals of an object (M = 394) for the two cases: (a1) q = 0.005, N₁ = 7.56 and (a2) q = 0.001, N₁ = 4.09. Corresponding effective values of object pixels, visibilities, and CNRs of quantum projection imaging are shown in (b1) and (b2), (c1) and (c2), (d1) and (d2), respectively. Bar charts are the theoretical simulations, and circles are the experimental results. In (b1) and (b2), the two lines under the horizontal axis show the range defined by Eq. (24). In (c1), (c2) and (d1), (d2), the lines indicate the corresponding values of CGI for comparison.

Fig. 3. (a1), (a2) Visibilities and (b1), (b2) CNRs for vacuum projection imaging, where p₁(0) is the vacuum probability for incident light on each micromirror, and N₁ is the corresponding average photon number for the Poisson distribution.

Fig. 4. Reconstructed images of a musical note are observed in four ways: VPGI, QPGI with k-photons, CGI, and FFPGI, in the three cases of different average photon numbers n_M and probabilities q.

Fig. 5. Reconstructed images of resolution bars in various combinations with VPGI (first column), CGI (second column), and NVPGI (third column). The corresponding photon number distributions of bucket detection are plotted in the fourth column. F is the number recorded in vacuum projection.

Fig. 6. Number of frames versus photon counts and reconstructed images of two Chinese characters with VPGI, CGI, and FFPGI in (a) “zhen” and (b) “kong.” The total number of frames is 40,000.