3,764 research outputs found

    Towards binocular active vision in a robot head system

    Get PDF
    This paper presents the first results of an investigation and pilot study into an active, binocular vision system that combines binocular vergence, object recognition and attention control in a unified framework. The prototype developed is capable of identifying, targeting, verging on and recognizing objects in a highly-cluttered scene without the need for calibration or other knowledge of the camera geometry. This is achieved by implementing all image analysis in a symbolic space without creating explicit pixel-space maps. The system structure is based on the ‘searchlight metaphor’ of biological systems. We present results of a first pilot investigation that yield a maximum vergence error of 6.4 pixels, while seven of nine known objects were recognized in a high-cluttered environment. Finally a “stepping stone” visual search strategy was demonstrated, taking a total of 40 saccades to find two known objects in the workspace, neither of which appeared simultaneously within the Field of View resulting from any individual saccade

    The Digital Anatomist Information System and Its Use in the Generation and Delivery of Web-Based Anatomy Atlases

    Get PDF
    Advances in network and imaging technology, coupled with the availability of 3-D datasets such as the Visible Human, provide a unique opportunity for developing information systems in anatomy that can deliver relevant knowledge directly to the clinician, researcher or educator. A software framework is described for developing such a system within a distributed architecture that includes spatial and symbolic anatomy information resources, Web and custom servers, and authoring and end-user client programs. The authoring tools have been used to create 3-D atlases of the brain, knee and thorax that are used both locally and throughout the world. For the one and a half year period from June 1995–January 1997, the on-line atlases were accessed by over 33,000 sites from 94 countries, with an average of over 4000 ‘‘hits’’ per day, and 25,000 hits per day during peak exam periods. The atlases have been linked to by over 500 sites, and have received at least six unsolicited awards by outside rating institutions. The flexibility of the software framework has allowed the information system to evolve with advances in technology and representation methods. Possible new features include knowledge-based image retrieval and tutoring, dynamic generation of 3-D scenes, and eventually, real-time virtual reality navigation through the body. Such features, when coupled with other on-line biomedical information resources, should lead to interesting new ways for managing and accessing structural information in medicine

    A Survey on MRI Brain Image Segmentation Technique

    Full text link
    One of the most dangerous disease occurring these days i.e. brain tumor can be detected by MRI images. Biomedical imaging and medical image processing that plays a vital role for MRI images has now become the most challenging field in engineering and technology. A detailed information about the anatomy can be showed through MRI images, that helps in monitoring the disease and is beneficial for the diagnosis as it consists of a high tissue contrast and have fewer artifacts. For tracking the disease and to proceed its treatment, MRI images plays a key role. It is having several advantages over other imaging techniques and is an important step for post-processing of medical images. However, having a large amount of data for manual analysis can sometimes proved to be an obstacle in the way of its effective use. In this paper, the introduction of image processing and the details of image segmentation techniques such as image preprocessing, feature extraction, image enhancement and classification of tumor processes, and how image segmentation can be applied to all Other available imaging modalities that are different from one another. This paper provides the survey on various methods used for image segmentation that have been applied for MRI images, that detects the tumor by segmenting the brain images into constituent parts. Also the advantages and disadvantages of Image segmentation is discussed using the various approaches of image segmentation of MRI brain images

    Internal meanings: Computed tomography scanning of Koma figurines from Ghana

    Get PDF
    This is the final version of the article. Available from the publisher via the DOI in this record.Since the 1980s art historians and archaeologists have been aware of the terracotta figurines from Koma Land in northern Ghana (Kröger 1988; Anquandah 1987, 1998). The pioneering excavation and publications by James Anquandah (Anquandah and van Ham 1985; Anquandah 1987, 1998) established their provenance, and unprovenanced figurines from illegal excavations have subsequently increased known numbers. The dominant focus in publication of the Koma Land corpus has been upon what the figurines depict externally (e.g., Anquandah 1987, 1998; Kankpeyeng and Nkumbaan 2008, 2009; Insoll and Kankpeyeng 2014; Insoll in press a). Following the successful trial use of lower resolution Computed Tomography black scanning which produced black-and-white images of five figurines in May 2010 (Insoll, Kankpeyeng, and Nkumbaan 2012:31–32), a further sample of eight terracotta figurines was CT scanned and color images produced in 2013. These are the focus here. All the figurines were from archaeological excavations at Yikpabongo in Koma Land, and the CT scanning indicated that all eight had deliberately made cavities running from their surface into the body of the figurine. This suggests that the importance of some of the figurines was potentially greater than their external appearance and that part of their significance might have been derived from their internal meanings as well. This paper reports on the renewed research in Koma Land that led to the retrieval of the figurines, and on the scanned figu rines themselves. Why the cavities were made is unknown, but various possibilities are explored. This is considered with reference to the Koma figurines and through wider comparison with other archaeological terracotta figurines from West Africa that have evidence for cavities

    The reproducibility of incomplete skulls using freeform modeling plus software

    Full text link
    As early as 1883, forensic artists and forensic anthropologists have utilized forensic facial reconstruction in the attempt to identify skulls from decomposed remains. Common knowledge dictates that in order to complete identification from the skull with facial reconstruction, the splanchnocranium (also known as the viscerocranium or facial portion of the skull) needs to still be intact. However, there has been very little research conducted (Colledge 1996; Ismail 2008; Wilkinson and Neave 2001) to determine the minimal amount of intact skull that can be present for a reconstruction to still be possible and accurate. Accordingly, in the present study, the researcher attempted to prove that a skull with significant damage to the splanchnocranium could be repaired and facially reconstructed to bear a likeness to the original skull and face. Utilizing FreeForm Modeling Plus Software, version 11.0 (Geomagic Solutions - Andover, MA), in conjunction with the Phantom Desktop Haptic Device (Geomagic Solutions - Andover, MA), five CT scans of males between 19 and 40 years old and of varying ethnicities (four Caucasian and one Asian) were digitally altered to present significant skull damage to the splanchnocranium. The hard tissue digital images were repaired using the same software mentioned above and template skulls (i.e., superfluous CT scanned skulls of similar age, sex, and ancestry). The soft tissue digital images were facially reconstructed also utilizing the same software mentioned above and by following basic tissue depth charts/placement rules and guidelines for feature reconstruction. The reconstructed images were compared to their original CT scans in a side-by-side comparison. Assessors were given a rating scale rubric to fill out that asked them specific questions pertaining to both certain facial features and overall similarity between the original and reconstructed images. Two of the reconstructions each ranked an overall 29% "close resemblance" to their original counterparts, one was ranked an overall 71% "no resemblance" to its original counterpart, and the other three fell somewhere in the middle ("slight" or "approximate") in the rating scale. The results reflected a number of issues related to this project (i.e., the researcher's lack of artistic skill) and to facial reconstruction in general (i.e., tissue depth measurement charts) and showed that while it is not impossible to reconstruct skulls that had been damaged in some capacity, the accuracy of the resulting facial reconstruction is questionable. Future studies would benefit from using an artist to reconstruct the images rather than someone with little to no experience in the field, a larger sample size consisting of one ancestry to avoid the cross-race effect, a comparison of the original skull to the repaired one utilizing Geomagic Qualify (Geomagic Solutions - Andover, MA) to glean an overall view of the project's accuracy, and utilization of a photo lineup as the method of comparison in addition to a side-by-side comparison to give a more realistic feel to the comparison process

    The state of the art of medical imaging technology: from creation to archive and back.

    Get PDF
    Medical imaging has learnt itself well into modern medicine and revolutionized medical industry in the last 30 years. Stemming from the discovery of X-ray by Nobel laureate Wilhelm Roentgen, radiology was born, leading to the creation of large quantities of digital images as opposed to film-based medium. While this rich supply of images provides immeasurable information that would otherwise not be possible to obtain, medical images pose great challenges in archiving them safe from corrupted, lost and misuse, retrievable from databases of huge sizes with varying forms of metadata, and reusable when new tools for data mining and new media for data storing become available. This paper provides a summative account on the creation of medical imaging tomography, the development of image archiving systems and the innovation from the existing acquired image data pools. The focus of this paper is on content-based image retrieval (CBIR), in particular, for 3D images, which is exemplified by our developed online e-learning system, MIRAGE, home to a repository of medical images with variety of domains and different dimensions. In terms of novelties, the facilities of CBIR for 3D images coupled with image annotation in a fully automatic fashion have been developed and implemented in the system, resonating with future versatile, flexible and sustainable medical image databases that can reap new innovations

    How the Brain Makes Up the Mind: a heuristic approach to the hard problem of consciousness

    Get PDF
    A solution to the “hard problem” requires taking the point of view of the organism and its sub- agents. The organism constructs phenomenality through acts of fiat, much as we create meaning in language, through the use of symbols that are assigned meaning in the context of an embodied evolutionary history. Phenomenality is a virtual representation, made to itself by an executive agent (the conscious self), which is tasked with monitoring the state of the organism and its environment, planning future action, and coordinating various sub-agencies. Consciousness is not epiphenomenal and serves a function for higher organisms that is distinct from unconscious processing. While a strictly scientific solution to the hard problem is not possible for a science that excludes the subjectivity it seeks to explain, there is hope to at least informally bridge the explanatory gulf between mind and matter
    corecore