Convenient noncooperative speckle-correlation imaging method

For speckle-correlation-based scattering imaging, an iris is generally used next to the diffuser to magnify the speckle size and enhance the speckle contrast, which limits the light flux and makes the setup cooperative. Here, we experimentally demonstrate a non-iris speckle-correlation imaging method associated with an image resizing process. The experimental results demonstrate that, by estimating an appropriate resizing factor, our method can achieve high-fidelity noncooperative speckle-correlation imaging by digital resizing of the raw captions or on-chip pixel binning without iris. The method opens a new door for noncooperative high-frame-rate speckle-correlation imaging and benefits scattering imaging for dynamic objects hidden behind opaque barriers.