Paper
1 June 2005 Automated control of LED-based illumination using image analysis metrics
Stephen Mills, Joseph Connell, Oliver P. Gough
Author Affiliations +
Abstract
In this paper we discuss a microprocessor controlled illumination system that covers the visible spectrum. The system uses multiple discrete wavelength LEDs. Uniform intensity illumination is 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. Current control is also used to maintain a spatially and spectrally homogenous illumination. Image analysis techniques are then used to parameterise the recorded scene and 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 iterated so as to maximise the image quality against embedded quality function benchmarks.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Stephen Mills, Joseph Connell, and Oliver P. Gough "Automated control of LED-based illumination using image analysis metrics", Proc. SPIE 5823, Opto-Ireland 2005: Imaging and Vision, (1 June 2005); https://doi.org/10.1117/12.606986
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KEYWORDS
Light emitting diodes

Image quality

Cameras

Image analysis

Diffusers

Image processing

Machine vision

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