Dileepan Joseph

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During the last ten years the Lattice Boltzmann Equation (LBE) method has been developed as an alternative numerical approach in computational fluid dynamics (CFD). Originated from the discrete kinetic theory, the LBE method has emerged with the promise to become a superior modeling platform, both computationally and conceptually, compared to the existing(More)
Logarithmic cameras have the wide dynamic range required to image natural scenes and encode the important contrast information within the scene. However, the images from these cameras are severely degraded by fixed pattern noise. Previous attempts to improve the quality of images from these cameras by removing additive fixed pattern noise have lead to(More)
Logarithmic CMOS image sensors capture high dynamic range scenes without saturation or loss of perceptible detail but problems exist with image quality. This thesis develops and applies methods of modelling and calibration to understand and improve the fixed pattern noise (FPN) and colour rendition of logarithmic imagers. Chapter 1 compares CCD and CMOS(More)
Wide dynamic range logarithmic imagers can render naturally illuminated scenes while preserving detail and contrast information at a lower cost than high dynamic range linear sensors. However, the quality of the output is severely degraded by fixed pattern noise (FPN). Although previous FPN correction techniques can eliminate the dominant additive form of(More)
A delta-sigma analog-to-digital-converter (ADC) is designed, optimized and simulated for column-level data conversion in a CMOS image sensor. For a 0.18μm process, the design achieves 80dB of signal-to-noise ratio (SNR), including a 10dB margin for kTC noise not simulated, and consumes 210μW of power at a 50kHz sampling rate. Low power is realized mainly by(More)
The quality of the output images from high dynamic range logarithmic sensors is limited by fixed pattern noise (FPN) which is caused by device mismatches within pixels in an array. It leads to inferior image quality in comparison to images from other sensors of similar resolution. Previous design and post-chip attempts to correct this type of noise, have(More)
All things considered, electronic imaging systems do not rival the human visual system despite notable progress over 40 years since the invention of the CCD. This work presents a method that allows design engineers to evaluate the performance gap between a digital camera and the human eye. The method identifies limiting factors of the electronic systems by(More)
Area and power optimization of a first-order deltasigma analog-to-digital converter (ADC) for pixel-level data conversion is presented. The ADC is designed for use in a verticallyintegrated logarithmic CMOS image sensor. A switched-capacitor modulator with minimum area has been employed. Unlike other similar structures, the decimation is performed inside(More)