Date of Award
2005
Document Type
Master Thesis
Degree Name
Master of Engineering (Research)
Department
Electronic Engineering
First Advisor
Dr. Joe Connell
Second Advisor
Dr. Oliver Gough
Abstract
This project discusses a microprocessor controlled illumination system that covers the visible spectrum. It uses multiple discrete wavelength LEDs. Spatial and spectral illumination profiles are achieved by controlling LED currents with an array of voltage controlled current sources. A highly efficient polycarbonate holographic diffuser is used to improve the uniformity of the distribution. System design is underpinned by accurate characterisation and modelling of the LEDs used.
Image analysis techniques are then used to parameterise the recorded scene and to provide a figure of merit for the quality of the illumination. Several functions such as contrast, low/high saturation, average brightness and histogram entropy are applied to extract objective quality Judgements and to compute an overall quality function. This process is then repeated to iterate the current controlled illumination towards an optimal image quality at an optimal convergence rate.
Recommended Citation
Mills, Stephen, "Automated Control of LED-based Illumination using Image Analysis Metrics" (2005). Theses [online].
Available at: https://sword.cit.ie/allthe/682
Access Level
info:eu-repo/semantics/openAccess