Positive-Negative Ghost Imaging with Statistics of Realizations

We report a thermal-light "ghost"imaging without conventional intensity correlation calculation. Typically, ghost imaging is achieved with correlation calculation not only for entangled photons but also for thermal-light sources. In this paper, we set only thresholds for the bucket detector and the reference detector, and count the realizations when their signals are above or below the thresholds simultaneously. The distribution of the counts shows the image of our target. With proper threshold restrictions on the two detectors, we demonstrate both positive and negative images. Our work broadens the ghost-imaging reconstruction method, and provides a potential approach to ghost imaging with binary detectors in low-light or photon-counting regimes and a broader spectrum.