This paper describes the design of a high-speed CMOS sampleand-hold (S/H) circuit for pipelined analog-to-digital converters (ADCs). This S/H circuit consists of a switched-capacitor (SC) amplifier and a comparator to generate the mixed-mode sampled output data, which are represented both in analog and digital forms. The mixed-mode sampling technique reduces the operational amplifier (op amp) o...

Correction of radial distortion of the image is a very important process during the calibration of non-metric camera intrinsic parameters. The paper treats the topic of estimation of coefficients and the centre of radial distortion of the image. A new method of coefficients and coordinates of the centre of radial distortion estimation in the image is presented. It is based on the iterative corr...

The main emphasis in modern RF power amplifier (PA) research is on improving linearity while at the same time maintaining reasonably good efficiency, for which purpose external linearization in the form of feedforward or predistortion is often used. Linearity and linearization can be considered from both a fundamental signal (amplitude and phase conversions, AM-AM & AM-PM) and an intermodulatio...

The majority of computer vision applications assume that the camera adheres to the pin-hole camera model. However, most real optical systems will introduce some undesirable effects, rendering the assumption of the pin-hole camera model invalid. By far the most evident of these effects is radial distortion, particularly in fish-eye camera systems where the level of this distortion is relatively ...

Welding-induced distortion is an intrinsic phenomenon arising due to the thermally induced strain distributions in the weld and surrounding material. The distortion can be minimized during the pre-process, real-time, or postprocess stages. In the present paper, the laser forming (LF) technology is utilized for the post correction of welding-induced distortion. The out-of-plane distortion can be...

In this paper some fundamentals and solutions to accompanying problems in vision system design for mobile robot tracking are presented. The main topics are correction of camera lens distortion and compensation of non-uniform illumination. Both correction methods contribute to vision system performance if implemented in the appropriate manner. Their applicability is demonstrated by applying them...

A well-recognized problem with the echo-planar imaging (EPI) technique most commonly used for functional magnetic resonance imaging (fMRI) studies is geometric distortion caused by magnetic field inhomogeneity. This makes it difficult to achieve an accurate registration between a functional activation map calculated from an EPI time series and an undistorted, high resolution anatomical image. A...

Optical distortion is one of the optical aberrations of optical systems that do not affect image sharpness. Thus, it can be beneficial to correct optical distortion computationally rather than optically. Computational correction versus optical correction will generally yields lighter optical systems. This is of great importance for head-mounted displays where the weight of the viewer needs to b...

The correction of distortion and design shape in manufactured components is increasingly in demand in industry, in particular for aluminium components, where the applications for aluminium and its alloys continue to expand. A process capable of achieving these actions in an automated, controlled and precise manner would be of significant benefit to industry. Due to these factors a study has bee...

Massive MIMO (multiple-input–multiple-output) is a multi-antenna technology for cellular wireless communication, where the base station uses a large number of individually controllable antennas to multiplex users spatially. This technology can provide a high spectral efficiency. One of its main challenges is the immense hardware complexity and cost of all the radio chains in the base station. T...