Estimating Dimensions of Free-Swimming Fish Using 3D Point Distribution Models

Tillett, R.D.; McFarlane, N.J.B.; Lines, J.A.

doi:10.1006/cviu.2000.0847

Cited by 46 publications

(17 citation statements)

References 15 publications

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“…This is not an easy task because of the wide morphological variation shown in corals even within a single species (Laforsch et al 2008). One approach is to use an imaging system to measure simple parameters like length, depth, or outline of an organism (Beddow et al 1996;Br€ ager and Chong 1999;Tillett et al 2000) or use image analysis to create simple 3D reconstructions to measure these parameters in different growth forms (Jones et al 2008). It is quick but it can represent an inaccurate approximation of the actual coral colony dimensions (Laforsch et al 2008).…”

mentioning

confidence: 99%

Simple methods for interactive 3D modeling, measurements, and digital databases of coral skeletons

Gutierrez-Heredia

D'Helft²,

Reynaud

2015

Limnology & Ocean Methods

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Coral studies rely on comparative research between several reference coral skeletons and living organisms imaged on reefs. However, many of these skeletons are part of collections, making extensive comparative works difficult. Nowadays, imaging technologies and image processing approaches allow acquisition of three‐dimensional (3D) datasets that can be converted to virtual models. These models can be made easily accessible and shared among collaborators or researchers using the Internet. Here, we compare high cost and low cost technologies on coral skeletons as well as imaging phantoms for accurate reference. We generated 3D models that were compared. Even though CT scanning and photogrammetry are the most accurate methods the latter is far less costly. It also allows for texture mapping, an essential tool in the field, and easy dataset handling. We submitted these 3D virtual models to experts for taxonomical identification, and they identified all specimens accurately. Finally, we further discuss applicability of our approach on museum collections, living corals, and field work.

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mentioning

confidence: 99%

Simple methods for interactive 3D modeling, measurements, and digital databases of coral skeletons

Gutierrez-Heredia

D'Helft²,

Reynaud

2015

Limnology & Ocean Methods

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“…Researchers estimated fish length by fitting Point‐Distribution Mode (PDM) manually (Tillett et al . ) or automatically (Lines et al . ) for segmenting fish images, which ultimately has been used to measure size and mass.…”

Section: Preharvestmentioning

confidence: 99%

“…Researchers estimated fish length by fitting Point-Distribution Mode (PDM) manually (Tillett et al 2000) or automatically (Lines et al 2001) for segmenting fish images, which ultimately has been used to measure size and mass. They successfully achieved 95% and 98% overall accuracy in comparison with manual measurement.…”

Section: Individual Fish Features Analysismentioning

confidence: 99%

Application of machine vision systems in aquaculture with emphasis on fish: state‐of‐the‐art and key issues

Saberioon

Gholizadeh

Císař

et al. 2016

Reviews in Aquaculture

185

109

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Demands of aquatic products are increasing dramatically during past decades. Also quality assurance has gradually received more attention by both producers and consumers. Thus, fish producers are exploring all possible approaches for improving the productivity and profitability. Monitoring of fish state and behaviour during cultivation may help to improve profitability for producers and also reduce the threat of severe loss because of disease and stress incidents. It is necessary to evaluate and measure quality of fish products in accurate, fast and objective way for meeting the different demands of the fish‐processing industry after harvesting. Traditional methods are usually time‐consuming, expensive, laborious and invasive. Using rapid, inexpensive and noninvasive methods is therefore important and desirable. Optical sensors and machine vision system provide the possibility of developing faster, cheaper and noninvasive methods for in situ and after harvesting monitoring of quality in aquaculture. This review describes the most recent technologies and the suitability of different optical sensors for the fish farming management and also assessment, measurement and prediction of fish products quality. Two major areas of optical sensors applications in aquaculture are discussed in this review: (i) preharvesting and during cultivation; and (ii) post‐harvesting. Finally, accuracy and uncertainty of optical sensors applications in aquaculture are discussed. This review showed that MVSs and optical sensors have found real‐world application based on tremendous possibility offered by digital camera development and increasing the speed of computer‐based processing; however, still new algorithms, methods and re‐engineered sensors need to be developed to meet real‐world requirements.

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“…A range of other marine biology applications also routinely use stereoimaging techniques (photo as well as video), including: fish monitoring (Ruff et al, 1995;Van Rooij et al, 1995;Li et al, 1996;Tillett et al, 2000;Harvey et al, 2003;Costa et al, 2006;Costa et al, 2009;Rooper et al, 2010;Bower et al, 2011;Torisawa et al, 2011); determination of the 3D structure of fish schools (Cullen et al, 1965;Pitcher, 1975;Dill et al, 1981;Sawada et al, 2009); determination of the influence of substrate complexity on the interaction between fish and the artificial substrate (Fischer et al, 2007); and surveys of the benthos and the sea floor (Emerey et al, 1965;Evans and Norris, 1997;Chong and Stratford, 2002;Jasiobedzki et al, 2008;Shortis et al, 2008;Svane et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

A practical guide to the use of consumer-level digital still cameras for precise stereogrammetric <I>in situ</I> assessments in aquatic environments

Wehkamp¹,

Fischer²

2014

uw tech: int j soc uw tech

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Scientists planning to use underwater stereoscopic image technologies are often faced with numerous problems during the methodological implementations: commercial equipment is too expensive; the setup or calibration is too complex; or the imaging processing (i.e. measuring objects in the stereo-images) is too complicated to be performed without a time-consuming phase of training and evaluation. The present paper addresses some of these problems and describes a workflow for stereoscopic measurements for marine biologists. It also provides instructions on how to assemble an underwater stereo-photographic system with two digital consumer cameras and gives step-by-step guidelines for setting up the hardware. The second part details a software procedure to correct stereo-image pairs for lens distortions, which is especially important when using cameras with non-calibrated optical units. The final part presents a guide to the process of measuring the lengths (or distances) of objects in stereoscopic image pairs. To reveal the applicability and the restrictions of the described systems and to test the effects of different types of camera (a compact camera and an SLR type), experiments were performed to determine the precision and accuracy of two generic stereo-imaging units: a diver-operated system based on two Olympus Mju 1030SW compact cameras and a cable-connected observatory system based on two Canon 1100D SLR cameras. In the simplest setup without any correction for lens distortion, the low-budget Olympus Mju 1030SW system achieved mean accuracy errors (percentage deviation of a measurement from the object's real size) between 10.2 and -7.6% (overall mean value: -0.6%), depending on the size, orientation and distance of the measured object from the camera. With the single lens reflex (SLR) system, very similar values between 10.1% and -3.4% (overall mean value: -1.2%) were observed. Correction of the lens distortion significantly improved the mean accuracy errors of either system. Even more, system precision (spread of the accuracy) improved significantly in both systems. Neither the use of a wide-angle converter nor multiple reassembly of the system had a significant negative effect on the results. The study shows that underwater stereophotography, independent of the system, has a high potential for robust and non-destructive in situ sampling and can be used without prior specialist training.

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Estimating Dimensions of Free-Swimming Fish Using 3D Point Distribution Models

Cited by 46 publications

References 15 publications

Simple methods for interactive 3D modeling, measurements, and digital databases of coral skeletons

Simple methods for interactive 3D modeling, measurements, and digital databases of coral skeletons

Application of machine vision systems in aquaculture with emphasis on fish: state‐of‐the‐art and key issues

A practical guide to the use of consumer-level digital still cameras for precise stereogrammetric <I>in situ</I> assessments in aquatic environments

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