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I suggest an irregular aperture and calculate the impulse response, or the point spread function (PSF) corresponding to this aperture. In addition, I calculated the PSF in the case of rotated irregular apertures. Secondly, I apply these irregular apertures to the confocal scanning laser microscope (CSLM). I obtained the images using the CSLM provided with irregular apertures and compared them with the case of uniform circular apertures. Finally, I differentiate speckle images that were obtained using different orientations of the irregular aperture. Then, I reconstructed the irregular aperture at different orientations from the speckle pattern. [ABSTRACT FROM AUTHOR]

Imaging using scattering media is a very important yet challenging technology. As one of the most widely used scattering imaging methods, speckle autocorrelation technology has important applications in several fields. However, traditional speckle autocorrelation imaging methods usually use iterative phase recovery algorithms to obtain the Fourier phase of hidden objects, posing issues such as large data calculation volumes and uncertain reconstruction results. Here, we propose a single-shot scattering imaging method based on the bispectrum truncation method. The bispectrum analysis is utilized for hidden object phase recovery, the truncation method is used to avoid the computation of redundant data when calculating the bispectrum data, and the method is experimentally verified. The experimental results show that our method does not require uncertain iterative calculations and can reduce the bispectrum data computation by more than 80% by adjusting the truncation factor without damaging the imaging quality, which greatly improves imaging efficiency. This method paves the way for rapid imaging through scattering media and brings benefits for imaging in dynamic situations.

• Simultaneous quantification of skin thickness and microcirculatory flow rate is reported for the first-time using laser speckle image analysis. • The experiments were carried out on a flow phantom with physiologically relevant measures for skin thickness, scatterer concentration and flow rate, specific to healthy and scleroderma tissue. • A multiparametric model is devised for classifying tissue status after a comprehensive analysis of the extracted speckle parameters. • This approach can be extended to other physical / biological models as well where the extracted speckle parameters are interlinked with structural and functional sample properties. Scleroderma is an autoimmune disorder caused by increased collagen deposition in the dermal layer of skin, which alters the dermal layer's thickness, affecting the local perfusion. In this article, we aim to build an experimental model to simultaneously quantify the dermal thickness and perfusion changes during scleroderma progression through a comprehensive analysis of various static and dynamic laser speckle image parameters. [ABSTRACT FROM AUTHOR]

Imaging using scattering media is a very important yet challenging technology. As one of the most widely used scattering imaging methods, speckle autocorrelation technology has important applications in several fields. However, traditional speckle autocorrelation imaging methods usually use iterative phase recovery algorithms to obtain the Fourier phase of hidden objects, posing issues such as large data calculation volumes and uncertain reconstruction results. Here, we propose a single-shot scattering imaging method based on the bispectrum truncation method. The bispectrum analysis is utilized for hidden object phase recovery, the truncation method is used to avoid the computation of redundant data when calculating the bispectrum data, and the method is experimentally verified. The experimental results show that our method does not require uncertain iterative calculations and can reduce the bispectrum data computation by more than 80% by adjusting the truncation factor without damaging the imaging quality, which greatly improves imaging efficiency. This method paves the way for rapid imaging through scattering media and brings benefits for imaging in dynamic situations.

• The laser speckle pattern scattered from a diffuse surface is used to track object surface motions and to extract object distance and orientation for system calibration. • The proposed system can track speckle motions resulting from microscopic in-plane displacements and out-of-plane rotations at a high accuracy (6.0 %) and repeatability (2.8 %) from a 30.7-m distance. • The system has high demonstrated tilt sensitivity down to 0.0006° and can simultaneously measure absolute macroscopic surface angles beyond 10°. • The proposed approach is suitable for measuring retroreflective surfaces, like traffic signs and number plates. Defocused Speckle Imaging (DSI) is a non-contact optical method that can measure multiaxial object motions at microscopic sensitivity using a simple and mechanically robust optical setup. The object surface is illuminated by a laser beam, and the scattered interference speckle pattern is tracked with a defocused camera. DSI measurement sensitivity increases with distance, and the sensitivity can be tuned by simple camera defocus adjustment. These characteristics make DSI an attractive choice for tracking remote objects in field conditions. However, the use of DSI for practical measurements is limited because the speckle signals due to linear and rotational surface motions mix together, and because the instrument calibration requires accurate object range and surface orientation parameters. To address these issues, the work described here combines two recently presented concepts: 1) a defocused camera pair, and 2) a diffraction-based self-calibration principle. The proposed approach was demonstrated by a series of self-calibrated multiaxial motion measurements performed at an extended (30.7-m) distance. The studied motions included in-plane displacements and out-of-plane rotations (tilts), whereas out-of-plane displacements and in-plane rotations were excluded. The experiments showed DSI's capability for high tilt sensitivity down to 0.0006°, standalone remote angle measurements, and suitability for retroreflective surfaces. The diffraction-based self-calibration approach could monitor sampling distances at a 6.4 % accuracy and the relative surface angles of 2.5–7.4° at a 0.2° accuracy. The defocused camera pair tracked microscopic in-plane displacements (400 µm) and very fine out-of-plane tilts (0.003°) at a high accuracy, with a maximum uncertainty of 6.0 %. The proposed DSI approach is particularly suited for monitoring large objects and for operating in hazardous environments. The findings pave a way for interesting new applications, like high-range remote angle measurements, high-sensitivity straightness measurements, and 3D-positioning utilizing retroreflective markers that already exist in the built infrastructure. [ABSTRACT FROM AUTHOR]