Confocal scanning microscopes are imaging systems that are mainly featured by their unique depth-discrimination capacity when imaging three-dimensional objects. Along the past few years, our research group has done several attempts to improve their axial resolution by means of the so-called point-spread-function (PSF) engineering method. That is, by designing diffractive elements that properly ...

Undersampling in the detector array degrades the performance of iris-recognition imaging systems. We find that an undersampling of 8 x 8 reduces the iris-recognition performance by nearly a factor of 4 (on CASIA iris database), as measured by the false rejection ratio (FRR) metric. We employ optical point spread function (PSF) engineering via a Zernike phase mask in conjunction with multiple su...

The point spread function (PSF) is an important property for predicting beam propagation and imaging system performance. Measurements of the PSF in three different locations (Pacific Ocean, Tongue of the Ocean, and Sargasso Sea) are presented. These measurements are used to validate extensive laboratory measurements [S. Q. Duntley, "Underwater Lighting by Submerged Lasers and Incandescent Sourc...

In this paper, we have examined the possibility of incorporating pulse compression techniques into a conventional medical B-scan imaging scheme. Linear frequency modulation fm, one form of pulse coding among many others, has been used in this study. With this approach, one can overcome current peak intensity limitations. A theoretical framework that includes medium propagation effects, transduc...

This paper concerns a special type of eddy-current sensor in the form of inductive loops. Such sensors are applied in the measuring systems classifying road vehicles. They usually have a rectangular shape with dimensions of 1 × 2 m, and are installed under the surface of the traffic lane. The wide Point Spread Function (PSF) of such sensors causes the information on chassis geometry, contained ...

Interactive simulation of point spread functions is an invaluable tool for evaluating optical designs. We present an interactive method for simulating the point spread function for designs that require diffraction and interference effects. These effects occure when the design contains apertures whose size approaches the wavelength of light, typically in the form of gratings or masks. Traditiona...

A new instrument to measure the point spread function (PSF) in the ocean is described. This instrument uses a CCD solid state camera to measure the angular radiance field due to a pulsed Lambertian source. In this way the PSF can be measured easily at sea, when precise alignments over ranges >10 m cannot be maintained. With the large dynamic range of the camera system, the PSF can be measured o...

Objective(s): The present study was conducted to examine whether the standardized uptake value (SUV) may be affected by the spatial position of a lesion in the radial direction on positron emission tomography (PET) images, obtained via two methods based on time-of-flight (TOF) reconstruction and point spread function (PSF). Methods: A cylinder phantom with the sphere (30mm diameter), located in...

Abstract In astronomy, upcoming space telescopes with wide-field optical instruments have a spatially varying point spread function (PSF). Specific scientific goals require high-fidelity estimation of the PSF at target positions where no direct measurement is provided. Even though observations are available some field view (FOV), they undersampled, noisy, and integrated into wavelength in instr...