Imaging objects through scattering layers and around corners by retrieval of the scattered point spread function

Abstract

Abstract:We demonstrate a high-speed method to image objects through thin scattering media and around corners. The method employs a reference object of known shape to retrieve the speckle-like point spread function of the scatterer. We extract the point spread function of the scatterer from a dynamic scene that includes a static reference object and uses this to image the dynamic objects. Sharp images are reconstructed from the transmission through a diffuser and from the reflection off a rough surface. The sharp and clean reconstructed images from single shot data exemplify the robustness of the method.

Passive sensing around the corner using spatial coherence

“…For instance, one can employ time-of-flight approaches to gate the time necessary for light emerging from a controllable source to first reach an object and then a detector capable of discriminating the transient time 8 , 9 . Imaging angularly small targets hidden around a corner is also possible when using additional measurements performed on reference objects 10 or when the scene is illuminated with temporally coherent light 11 – 14 . Sometimes, when an object is diffusively illuminated by a laser and its reflection generates a nonuniform intensity distribution across the scattering wall, detecting the evolution of this intensity allows tracking the object’s movement 15 , 16 .…”

Exploiting the point spread function for optical imaging through a scattering medium based on deconvolution method

“…Xu et al proposed a novel method to reconstruct a tested object through a thin scattering medium with the help of a known reference object. 44 As it is shown in Fig. 5, the model is to recover the target \T" from the scattering pattern I sum of the whole scene (letter mask of \TH") when the distribution O R of the reference object \H" and its speckle I R are known in advance.…”

“…Although the auto-correlation method can realize single-shot, noninvasive imaging reconstruction through a scattering medium, it usually su®ers from a large computation load phase retrieval calculation and a complicated calibration calculation. The deconvolution approach, 34,[39][40][41][42][43][44][45][46] instead, can reconstruct the image of the object from its speckle and the PSF of the scattering system 47 in real-time. By harnessing the spatial, spectral properties of the PSF of a scattering system, large Field-of-View (FOV) beyond the limit of the OME, 34,45,46 extended Depth-of-Field (DOF) for 3D imaging, 39 color image reconstruction, 34 or spectral-resolved imaging recovery 40,41 can be realized by a simple deconvolution between the speckle and the PSF.…”

“…By harnessing the spatial, spectral properties of the PSF of a scattering system, large Field-of-View (FOV) beyond the limit of the OME, 34,45,46 extended Depth-of-Field (DOF) for 3D imaging, 39 color image reconstruction, 34 or spectral-resolved imaging recovery 40,41 can be realized by a simple deconvolution between the speckle and the PSF. If a priori knowledge of a reference object, 44 spatial-correlation of the speckles, 45 or estimation of the speckle pattern 42 can be attained, noninvasive imaging recovery through a scattering medium can be realized. For its easy-to-use and robust qualities, the speckle correlation scattering imaging technique based on deconvolution is undergoing a rapid development.…”

Imaging and Tracking Through Scattering Medium With Low Bit Depth Speckle

“…As shown in these papers, the auto-correlation of the speckle pattern is identical to the auto-correlation of the object's image, so the object's image can be reconstructed by an iterative phase-retrieval algorithms [19]- [21]. Another method is measurement of the point spread function (PSF ) followed to recover the image with decorrelation techniques [22], [23]. Fast imaging and color imaging has been achieved in article [22] and letter [23] using this technique, respectively.…”