Experimental results of revised Misell algorithm for imaging through weakly scattering biological tissue Maya Aviv, 1, * Eran Gur, 2 and Zeev Zalevsky 1 1 Bar-Ilan University, Faculty of Engineering, Ramat-Gan 52900, Israel 2 Jerusalem College of Engineering, Department of Electronics Engineering, Jerusalem 91035, Israel *Corresponding author: maya.shalev@gmail.com Received 3 January 2013; revised 19 February 2013; accepted 22 February 2013; posted 25 February 2013 (Doc. ID 182368); published 4 April 2013 A Static random perturbation weakly scattering media may significantly reduce image quality, in many kinds of applications. An example of such a medium can be a soft tissue such as skin or flesh, through which one may wish to image an object, such as a bone, located behind. In this paper we present exper- imental results of newly developed deblurring approach for obtaining a better image of objects positioned behind static random perturbation media. This approach for extraction of the high spatial frequencies is based on iterative computation similar to the well-known Gerchberg–Saxton algorithm for phase retrieval. By focusing a camera onto three or more planes positioned between the imaging camera and the perturbation media, we are able to retrieve the phase distribution of those planes and then re- construct the intensity of the object by numerical free-space propagation of this extracted complex field, to the estimated position of the object. © 2013 Optical Society of America OCIS codes: 110.3010, 100.5070, 100.2980, 170.0110, 070.0070, 000.1430. 1. Introduction Many attempts have been made to retrieve the shape of objects that hide behind or within media that transmit and scatter light. Some of the photons that travel through such media do so without interacting with any of the medium’ s components. Other photons may be observed or scattered by the media. If an im- age is captured while the distance to the sensor is large enough [ 1, 2] then the “shower curtain effect” is avoided and the blurring effect of the scattering will be reduced. For stronger scattering media such as the skin tissue of a human hand (a common test for growth potential of kids [ 3]), ballistic light can only propagate a short distance of about a few milli- meters without being significantly scattered [ 4]. Therefore, image quality degrades as we attempt to see deeper into the tissue [ 5– 7]. Furthermore, the light transmitted through the tissue has an addi- tional blurring process, coming from the different op- tical length of each photon in the nonuniform tissue. It is much like a weakly scattering random perturba- tion medium [ 8]. Human skin (and soft tissue) from an optical point of view, is a layer with absorption spectra and light penetration depths [ 9]. The absorption is described in terms of melanin and hemoglobin absorption while the dermal scattering is described in terms of the relative contributions of Mie and Rayleigh scattering due to collagen fibers. For certain wave- lengths skin may have penetration depth such that it may optically behave as almost transparent [ 10]. It is somewhat similar to a case in which one wishes to image an object located inside a room while the imaging is done through a diffusive window. The im- age will experience higher distortion as the distance between the object and the glass is increased [ 11]. 1559-128X/13/112300-06$15.00/0 © 2013 Optical Society of America 2300 APPLIED OPTICS / Vol. 52, No. 11 / 10 April 2013