Vision System (vision + system)

Distribution by Scientific Domains

Kinds of Vision System

  • machine vision system


  • Selected Abstracts


    Vision system for on-line characterization of paper slurry ,

    INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 4 2000
    Hamed Sari-Sarraf
    This paper presents a detailed description of a vision system that detects and localizes the nonuniformities that appear on the paper slurry (wood fiber and water mixture) at the wet end of a paper machine. Specifically, the system monitors the paper slurry as it exits the headbox and alerts the operators of any event (e.g., streaks) that disrupts the otherwise homogeneous background. These events affect crucial product properties such as formation. A poor formation results in thick and thin spots on the sheet and impacts its strength and printability. This paper describes the vision system in terms of its hardware modules, as well as the image processing algorithms that it utilizes to perform its function. The system acquires intensity and topographic information from the scene. It uses texture-based features for the detection and facet-based descriptors for the localization of the nonuniformities. In addition to being tested in a laboratory environment, a prototype of this system was constructed and deployed to a paper mill, where its performance was evaluated under realistic conditions. Installed on a fourdrinier paper machine, running at 480 m/min and producing linerboard material, the vision system monitored about a 1 m wide area and successfully detected and localized slurry streaks. Published 2001 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 11, 231,242, 2000 [source]


    Improved upsampling filter design for spatially scalable video coding

    INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 5 2007
    Zhang Wang
    Abstract Scalable video coding is an ongoing standard, and the current working draft (WD) is to be finalized as an extension of H.264/AVC. It provides scalability at the bit stream level with good compression efficiency and allowing free combinations of spatial, temporal and quality scalability. In the WD, a uniform up-sampling filter is employed to interpolate the base layer frames. This technique achieves high interpolated precision for both luma component and chroma components, but it results in extremely large encoding time which obstructs it from practical use. This paper proposes an improved up-sampling filter design for spatially scalable video coding. It makes use of a basic characteristic of human vision system and intends to assign different filters for different components. Specifically, current usage of the 6-tap up-sampling filter is only for luma component, but for chroma components, much more simplified filter such as 4-tap filter or 2-tap filter should be used instead. Experimental results show that improved up-sampling filter design reduces the computational complexity significantly with negligible coding loss and bit-rate increases. © 2008 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 17, 315,319, 2007 [source]


    Vision system for on-line characterization of paper slurry ,

    INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 4 2000
    Hamed Sari-Sarraf
    This paper presents a detailed description of a vision system that detects and localizes the nonuniformities that appear on the paper slurry (wood fiber and water mixture) at the wet end of a paper machine. Specifically, the system monitors the paper slurry as it exits the headbox and alerts the operators of any event (e.g., streaks) that disrupts the otherwise homogeneous background. These events affect crucial product properties such as formation. A poor formation results in thick and thin spots on the sheet and impacts its strength and printability. This paper describes the vision system in terms of its hardware modules, as well as the image processing algorithms that it utilizes to perform its function. The system acquires intensity and topographic information from the scene. It uses texture-based features for the detection and facet-based descriptors for the localization of the nonuniformities. In addition to being tested in a laboratory environment, a prototype of this system was constructed and deployed to a paper mill, where its performance was evaluated under realistic conditions. Installed on a fourdrinier paper machine, running at 480 m/min and producing linerboard material, the vision system monitored about a 1 m wide area and successfully detected and localized slurry streaks. Published 2001 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 11, 231,242, 2000 [source]


    Nestling coloration is adjusted to parent visual performance in altricial birds irrespective of assumptions on vision system for Laniidae and owls, a reply to Renoult et al.

    JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 1 2010
    J. M. AVILÉS
    Abstract We have recently published support to the hypothesis that visual systems of parents could affect nestling detectability and, consequently, influences the evolution of nestling colour designs in altricial birds. We provided comparative evidence of an adjustment of nestling colour designs to the visual system of parents that we have found in a comparative study on 22 altricial bird species. In this issue, however, Renoult et al. (J. Evol. Biol., 2009) question some of the assumptions and statistical approaches in our study. Their argumentation relied on two major points: (1) an incorrect assignment of vision system to four out of 22 sampled species in our study; and (2) the use of an incorrect approach for phylogenetic correction of the predicted associations. Here, we discuss in detail re-assignation of vision systems in that study and propose alternative interpretation for current knowledge on spectrophotometric data of avian pigments. We reanalysed the data by using phylogenetic generalized least squares analyses that account for the alluded limitations of phylogenetically independent contrasts and, in accordance with the hypothesis, confirmed a significant influence of parental visual system on gape coloration. Our results proved to be robust to the assumptions on visual system evolution for Laniidae and nocturnal owls that Renoult et al. (J. Evol. Biol., 2009) study suggested may have flawed our early findings. Thus, the hypothesis that selection has resulted in increased detectability of nestling by adjusting gape coloration to parental visual systems is currently supported by our comparative data. [source]


    Vision-based terrain characterization and traversability assessment

    JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 10 2001
    Ayanna Howard
    This article presents novel techniques for real-time terrain characterization and assessment of terrain traversability for a field mobile robot using a vision system and artificial neural networks. The key terrain traversability characteristics are identified as roughness, slope, discontinuity, and hardness. These characteristics are extracted from imagery data obtained from cameras mounted on the robot and are represented in a fuzzy logic framework using perceptual, linguistic fuzzy sets. The approach adopted is highly robust and tolerant to imprecision and uncertainty inherent in sensing and perception of natural environments. The four traversability characteristics are combined to form a single Fuzzy Traversability Index, which quantifies the ease-of-traversal of the terrain by the mobile robot. Experimental results are presented to demonstrate the capability of the proposed approach for classification of different terrain segments based on their traversability. © 2001 John Wiley & Sons, Inc. [source]


    Machine Vision Analysis of Antibrowning Potency for Oxalic Acid: A Comparative Investigation on Banana and Apple

    JOURNAL OF FOOD SCIENCE, Issue 6 2004
    R. Yoruk
    ABSTRACT: Relative antibrowning potency of oxalic acid on banana and apple slices was investigated using a machine vision system. Degree of browning on fresh-cut surfaces was evaluated visually and quantitatively by observing changes of CIE L* values and evaluating temporal changes in color spectra based on experimental variables, oxalic acid concentration, and storage time. Browning inhibition was most prominent on banana and apple slices treated with oxalic acid solutions at concentrations of 60 and 5 mM, respectively. Oxalic acid was a more potent antibrowning agent compared with other structurally related acids. Average residual oxalic acid levels in the tissues for an effective antibrowning activity were measured. [source]


    Comparison of Minolta colorimeter and machine vision system in measuring colour of irradiated Atlantic salmon

    JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 4 2009
    Yavuz Yagiz
    Abstract BACKGROUND: Minolta and machine vision are two different instrumental techniques used for measuring the colour of muscle food products. Between these two techniques, machine vision has many advantages, such as its ability to determine L*, a*, b* values for each pixel of a sample's image and to analyse the entire surface of a food regardless of surface uniformity and colour variation. The objective of this study was to measure the colour of irradiated Atlantic salmon fillets using a hand-held Minolta colorimeter and a machine vision system and to compare their performance. RESULTS: The L*, a*, b* values of Atlantic salmon fillets subjected to different electron beam doses (0, 1, 1.5, 2 and 3 kGy) were measured using a Minolta CR-200 Chroma Meter and a machine vision system. For both Minolta and machine vision the L* value increased and the a* and b* values decreased with increasing irradiation dose. However, the machine vision system showed significantly higher readings for L*, a*, b* values than the Minolta colorimeter. Because of this difference, colours that were actually measured by the two instruments were illustrated for visual comparison. Minolta readings resulted in a purplish colour based on average L*, a*, b* values, while machine vision readings resulted in an orange colour, which was expected for Atlantic salmon fillets. CONCLUSION: The Minolta colorimeter and the machine vision system were very close in reading the standard red plate with known L*, a*, b* values. Hence some caution is recommended in reporting colour values measured by Minolta, even when the ,reference' tiles are measured correctly. The reason for this discrepancy in colour readings for salmon is not known and needs further investigation. Copyright © 2009 Society of Chemical Industry [source]


    Morphological development of post hatch larval goldlined seabream Rhabdosargus sarba (Forskĺl, 1775)

    AQUACULTURE RESEARCH, Issue 12 2006
    Fahad S Ibrahim
    Abstract Ultrastructural changes in Rhabdosargus sarba larva in early life history were investigated. At hatching, the digestive system was histologically undifferentiated. The digestive tract was a straight tube attached to the dorsal end of the yolk-sac and was not connected to either the mouth or the anus. The layer of gut epithelium at some regions of the luminal surface was straight and microvilli were not present. These straight borders were not observed at 1 day post hatching (DPH) onwards as microvilli increased in number on the luminal surface and became more regular. At 2 DPH, the digestive system was well differentiated and the separation of the mid- and hindgut by the intestino-rectal valve became more advanced. At 0 DPH, the eye was spherical and the retina had a zonation with undifferentiated cells. The eye also lacked differentiated photoreceptors (PR). The retinal PRs increased in length and in number as the yolk-sac was absorbed. By 2 DPH, the eye was fully pigmented, suggesting that the larval vision system was functional. The larvae had a pure cone retina at the onset of exogenous feeding. Morphological and functional differentiation of the digestive tract and the eye of the larvae preceded the completion of yolk and oil globule absorption. The oil globule was exhausted at 4 DPH and at 2 DPH, the yolk-sac was completely absorbed. Food particles were observed at 3 DPH. Food particle ingestion and absorption of the yolk-sac were observed as vision became fully functional. [source]


    Behavioral Monitoring of Trained Insects for Chemical Detection

    BIOTECHNOLOGY PROGRESS, Issue 1 2006
    Glen C. Rains
    A portable, handheld volatile odor detector ("Wasp Hound") that utilizes a computer vision system and Microplitis croceipes (Cresson) (Hymenoptera: Braconidae), a parasitoid wasp, as the chemical sensor was created. Five wasps were placed in a test cartridge and placed inside the device. Wasps were either untrained or trained by associative learning to detect 3-octanone, a common fungal volatile chemical. The Wasp Hound sampled air from the headspace of corn samples prepared within the lab and, coupled with Visual Cortex, a software program developed using the LabView graphical programming language, monitored and analyzed wasp behavior. The Wasp Hound, with conditioned wasps, was able to detect 0.5 mg of 3-octanone within a 240 mL glass container filled with feed corn (,2.6 × 10,5 mol/L). The Wasp Hound response to the control (corn alone) and a different chemical placed in the corn (0.5 mg of myrcene) was significantly different than the response to the 3-octanone. Wasp Hound results from untrained wasps were significantly different from trained wasps when comparing the responses to 3-octanone. The Wasp Hound may provide a unique method for monitoring grains, peanuts, and tree nuts for fungal growth associated with toxin production, as well as detecting chemicals associated with forensic investigations and plant/animal disease. [source]


    Robotic surgery in urology: fact or fantasy?

    BJU INTERNATIONAL, Issue 8 2004
    Jochen Binder
    Advanced robotic surgery was first introduced into urology in 2000. The first studies showed the feasibility and safety of the daVinci (Intuitive Surgical Inc., Sunnyvale, CA) telemanipulator assistance in radical prostatectomy, pelvi-ureteric junction obstruction, and radical cystectomy and neobladder formation. The miniature endowristed tools offer a potential advantage over standard laparoscopy in the accuracy of preparation and suturing. Other features are a three-dimensional vision system and unimpaired hand-eye coordination. Complex laparoscopic tasks are learned faster by using the robot, which may also explain the shorter training required for radical prostatectomy than for manual laparoscopy. This new and expensive technology has spread rapidly over the last 4 years. By 2004, ,,10% of radical prostatectomies in the USA will be robot-assisted. Data on the functional and oncological outcomes are accruing but not yet conclusive. There will be a further spread of robotic surgery, routine telesurgery, smaller and more affordable systems, the introduction of virtual reality, all developments which have the potential to urological surgeons to improve. [source]


    Aspect graphs for three-dimensional object recognition machine vision systems

    INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 1 2005
    Tatiana Tambouratzis
    The purpose of this research is to seek evidence for viewer-centered (especially aspect-graph-based) visual processing in the elementary task of object understanding. Two homologous, bilaterally symmetrical three-dimensional (3-D) objects have been employed that differ in that one is based on parts with flat surfaces and the other on parts with curved surfaces. The following procedure has been followed, separately for each object. In the training (saturated free inspection and manipulation) phase, a location (identical for both objects) of the object is marked with a red strip and the subjects' task is to memorize the object structure as well as the position of the strip. In the test phase, two-dimensional views of the object without the strip are presented and the subjects' task is to determine whether the previously marked location should be visible or invisible in the particular view. Findings have been found consistent with an aspect-graph-based 3-D object representation: (a) the reaction times and errors show characteristic dependencies on viewpoint; (b) a number of views (corresponding to certain aspects and aspect transitions of the aspect graph) consistently produce faster and more accurate recognition; (c) the differences in the aspect graphs of the two objects are reflected in differing patterns of reaction times and errors; furthermore; (d) the subjects impose a standard orientation on the objects, whereby a strong inversion effect is observed; and (e) performance varies in a similar way for both objects as a function of tilt. It is concluded that object understanding is viewpoint dependent, that is, based on a number of views. The characteristics of the views found to be most important for object understanding can be employed for creating efficient 3-D object recognition machine vision systems. © 2005 Wiley Periodicals, Inc. Int J Int Syst 20: 47,72, 2005. [source]


    Nestling coloration is adjusted to parent visual performance in altricial birds irrespective of assumptions on vision system for Laniidae and owls, a reply to Renoult et al.

    JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 1 2010
    J. M. AVILÉS
    Abstract We have recently published support to the hypothesis that visual systems of parents could affect nestling detectability and, consequently, influences the evolution of nestling colour designs in altricial birds. We provided comparative evidence of an adjustment of nestling colour designs to the visual system of parents that we have found in a comparative study on 22 altricial bird species. In this issue, however, Renoult et al. (J. Evol. Biol., 2009) question some of the assumptions and statistical approaches in our study. Their argumentation relied on two major points: (1) an incorrect assignment of vision system to four out of 22 sampled species in our study; and (2) the use of an incorrect approach for phylogenetic correction of the predicted associations. Here, we discuss in detail re-assignation of vision systems in that study and propose alternative interpretation for current knowledge on spectrophotometric data of avian pigments. We reanalysed the data by using phylogenetic generalized least squares analyses that account for the alluded limitations of phylogenetically independent contrasts and, in accordance with the hypothesis, confirmed a significant influence of parental visual system on gape coloration. Our results proved to be robust to the assumptions on visual system evolution for Laniidae and nocturnal owls that Renoult et al. (J. Evol. Biol., 2009) study suggested may have flawed our early findings. Thus, the hypothesis that selection has resulted in increased detectability of nestling by adjusting gape coloration to parental visual systems is currently supported by our comparative data. [source]


    Design evolution of the trinity college IGVC robot ALVIN

    JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 9 2004
    Michelle Bovard
    In this paper we discuss the design and evolution of Trinity College's ALVIN robot, an autonomous ground vehicle that has participated in the Association for Unmanned Vehicle Systems International Intelligent Ground Vehicle Competition (IGVC) since 2000. The paper first discusses the Trinity Robot Study Team, which has been responsible for developing ALVIN. We then illustrate the four generations of ALVIN, focusing on improvements made as the result of performance shortcomings and outright failures. The discussion considers the robot's body design, drive system, sensors, navigation algorithms, and vision systems. We focus especially on the vision and navigation systems developed for Trinity's fourth-generation IGVC robot, ALVIN IV. The paper concludes with a plan for future work on ALVIN and with a discussion of educational outcomes resulting from the ALVIN project. © 2004 Wiley Periodicals, Inc. [source]