Aberration-free superresolution imaging via binary speckle pattern encoding and processing

Abstract

We present an approach that provides superresolution beyond the classical limit as well as image restoration in the presence of aberrations; in particular, the ability to obtain superresolution while extending the depth of field (DOF) simultaneously is tested experimentally. It is based on an approach, recently proposed, shown to increase the resolution significantly for in-focus images by speckle encoding and decoding. In our approach, an object multiplied by a fine binary speckle pattern may be located anywhere along an extended DOF region. Since the exact magnification is not known in the presence of defocus aberration, the acquired low-resolution image is electronically processed via a parallel-branch decoding scheme, where in each branch the image is multiplied by the same high-resolution synchronized time-varying binary speckle but with different magnification. Finally, a hard-decision algorithm chooses the branch that provides the highest-resolution output image, thus achieving insensitivity to aberrations as well as DOF variations. Simulation as well as experimental results are presented, exhibiting significant resolution improvement factors.

Super-resolved imaging with randomly distributed, time- and size-varied particles

“…Later on, instead of a periodic pattern a random pattern of speckles was used to improve the resolution [23][24][25][26]. This random pattern encoded the high spatial frequencies existing in the object.…”

Transverse resolution improvement using rotating-grating time-multiplexing approach

“…Another way to achieve time-multiplexing SR is by using speckle patterns [31,32] instead of grating ones. Speckle patterns can be understood as a continuous case of the discrete one (represented by a diffraction grating) in which one can achieve two-dimensional (2-D) SR by simply coding-decoding the input and the output, respectively, with a given speckle pattern.…”

Long working distance high resolution reflective sample imaging via structured embedded speckle illumination

“…More recently, for high-resolution imaging and optical sectioning in fluorescence microscopy, the use of speckle pattern illumination instead of periodic grating illumination (used for SIM) was suggested [28][29][30][31][32][33]. To date, several techniques have been proposed to perform highresolution imaging, which may be separated into three basic categories.…”

“…To date, several techniques have been proposed to perform highresolution imaging, which may be separated into three basic categories. In the first category, super resolution imaging is achieved by combining optical processing techniques followed by digital restoration [28][29][30][31][32][33]. In the optical processing phase, a speckle-encoded input is generated by imaging a series of time variant, random or correlated speckle patterns projected onto the sample via a low NA objective lens.…”