An optical method for the detection of sea lice, Lepeophtheirus salmonis
نویسنده
چکیده
Developments towards a novel video camera based system for estimating the sea lice burden of freely swimming salmon are reported. The spectral reflectance of sea lice and salmon skin were measured over the wavelength range 400–1100 nm. Canonical variate analysis was then used to identify a combination of reflectances that maximises the differences between skin and sea lice. This is shown to provide good discrimination when the lice are attached to the lighter underside of the fish and a degree of discrimination when the lice are attached to the darker areas. The results of this analysis were used to develop a simple video based discrimination system. An image of the salmon is synthesised from the ratio of grey levels of images taken through narrow band pass filters at wavelengths of 700 and 800 nm. This enhances the visibility of the lice and suppresses variations in the skin colour. Further development of this technique could lead to an automated passive system for estimating lice burden. © 1999 Elsevier Science B.V. All rights reserved. www.elsevier.nl/locate/aqua-online
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