Videoendoscopy is becoming increasingly popular in surgical procedures. Wide-angle lenses are commonly employed in such applications for enhanced viewing capability. However, images captured with these lenses suffer from barrel distortion. 2D distortion correction for images captured with wide-angle lenses has been widely investigated. In clinical applications, it is necessary to incorporate co...

Accurately characterizing third order intermodulation distortion (IMD3) in high-linearity photodiodes is challenging. Two measurement techniques are evaluated-a standard two-tone measurement and a more complicated three-tone measurement technique to measure IMD3. A model of the measurement system is developed and used to analyze the limitations of the two techniques in determining the distortio...

Optical imaging systems often suffer from distortion artifacts which impose important limitations on the direct interpretation of the images. It is possible to correct for these aberrations through image processing, but due to their calculation-intensive nature, the required corrections are typically performed offline. However, with image-based applications that operate interactively, real-time...

Triangular patterns phase shifting profilometry is a method of structured light whose three-dimensional reconstructions are susceptible to error from gamma distortion. In practice, the luminance nonlinearity caused by the gamma distortion effect of a digital projector and a digital camera yields undesired fringe intensity changes, which substantially reduce the measurement accuracy, and while t...

The RF sections of Analog FM and Digital Radios primarily differ in the required linearity. If the transmitter amplifiers and attendant switching functions are not extremely linear, AM to AM and AM to PM conversion can cause serious deterioration of Bit Error Rate (BER) and an increase in intersymbol interference (ISI). Higher order QAM Systems such as 64-QAM and 256-QAM require even higher lev...

In this paper, the significance of linearity for UWB front-end circuit is discussed. The effects of strong narrow band interferer on UWB signal are investigated. Wideband linearization techniques for UWB LNA are first proposed in this work. A high linearity UWB LNA is designed in TSMC 0.18μ CMOS process The simulation results show that the designed LNA exhibits very high IIP3 (6.9~13.8 dBm) whi...

In this article, a novel concept is introduced to improve the Radio Frequency (RF) linearity of Partially-Depleted (PD) Silicon-On-Insulator (SOI) MOSFET circuits. The transition due to the non-zero body resistance (RBody) in output conductance of PD SOI devices leads to linearity degradation. A relation for RBody is defined to eliminate the transition and a method to obtain transition-free cir...

We address the measurement and correction of fan distortion in optical coherence tomography (OCT). This effect arises from the scanning system configuration and prevents one, in general, from obtaining quantitative topographic data from OCT. Computer simulations allowed us to quantify the effect and evaluate its dependence on the scanning mirror separation and design of the collimating lens, as...

The detailed analysis of measured interferograms generally requires phase correction. Phase-shift correction methods are commonly used and well documented for conventional Fourier-transform spectroscopy. However, measured interferograms can show additional phase errors, depending on the optical path difference and signal frequency, which we call phase distortion. In spatial heterodyne spectrosc...

In the fields of computer aided celiac disease diagnosis, wideangle endoscopy lenses are employed which introduce a significant degree of barrel type distortion. In recent studies on celiac disease classification, distortion correction techniques are investigated which use interpolation techniques, in order to maintain the rasterization of the image. Subsequent feature extraction is based on th...