508 research outputs found

    The adaptation of a 360° camera utilising an alternate light source (ALS) for the detection of biological fluids at crime scenes.

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    One of the most important and commonly encountered evidence types that can be recovered at crime scenes are biological fluids. Due to the ephemeral nature of biological fluids and the valuable DNA that they can contain, it is fundamental that these are documented extensively and recovered rapidly. Locating and identifying biological fluids can prove a challenging task but can aid in reconstructing a sequence of events. Alternate light sources (ALS) offer powerful non-invasive methods for locating and enhancing biological fluids utilising different wavelengths of light. Current methods for locating biological fluids using ALS's may be time consuming, as they often require close range searching of potentially large crime scenes. Subsequent documentation using digital cameras and alternate light sources can increase the investigation time and due to the cameras low dynamic range, photographs can appear under or over exposed. This study presents a technique, which allows the simultaneous detection and visualisation of semen and saliva utilising a SceneCam 360° camera (Spheron VR AG), which was adapted to integrate a blue Crime Lite XL (Foster+Freeman). This technique was investigated using different volumes of semen and saliva, on porous and non-porous substrates, and the ability to detect these at incremental distances from the substrate. Substrate type and colour had a significant effect on the detection of the biological fluid, with limited fluid detection on darker substrates. The unique real-time High Dynamic range (HDR) ability of the SceneCam significantly enhanced the detection of biological fluids where background fluorescence masked target fluorescence. These preliminary results are presented as a proof of concept for combining 360° photography using HDR and an ALS for the detection of biological stains, within a scene, in real time, whilst conveying spatial relationships of staining to other evidence. This technique presents the opportunity to presumptively screen a crime scene for biological fluids and will facilitate simultaneous location and visualisation of biological evidence

    Self-Tracking Cycling Data as Representations of Landscape

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    Video collections in panoramic contexts

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    A virtual reality system using the concentric mosaic: Construction, rendering, and data compression

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    This paper proposes a new image-based rendering (IBR) technique called "concentric mosaic" for virtual reality applications. IBR using the plenoptic function is an efficient technique for rendering new views of a scene from a collection of sample images previously captured. It provides much better image quality and lower computational requirement for rendering than conventional three-dimensional (3-D) model-building approaches. The concentric mosaic is a 3-D plenoptic function with viewpoints constrained on a plane. Compared with other more sophisticated four-dimensional plenoptic functions such as the light field and the lumigraph, the file size of a concentric mosaic is much smaller. In contrast to a panorama, the concentric mosaic allows users to move freely in a circular region and observe significant parallax and lighting changes without recovering the geometric and photometric scene models. The rendering of concentric mosaics is very efficient, and involves the reordering and interpolating of previously captured slit images in the concentric mosaic. It typically consists of hundreds of high-resolution images which consume a significant amount of storage and bandwidth for transmission. An MPEG-like compression algorithm is therefore proposed in this paper taking into account the access patterns and redundancy of the mosaic images. The compression algorithms of two equivalent representations of the concentric mosaic, namely the multiperspective panoramas and the normal setup sequence, are investigated. A multiresolution representation of concentric mosaics using a nonlinear filter bank is also proposed.published_or_final_versio

    An Evaluation of the Use of 360° Photographic Technology in a Forensic Context

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    Crime scenes represent ephemeral and complex environments and the intelligence and evidence that they contain requires them to be documented and collected quickly and efficiently so as to limit any loss of evidence. With the continuous developments of new imaging and recording technologies, there is the opportunity for more innovative and appropriate methods for documenting and managing crime scenes that may improve investigative proffered to the Criminal Justice system and indeed the public. This thesis has explored the potential of new panoramic imaging technologies and crime scene management content software to assist and develop the way in which criminal investigations are investigated, and conducted starting with how crime scenes are recorded and evidence linked with them. There is currently a vast array of differing panoramic imaging technologies available to Police services such as SceneVision Panorama, Panoscan MK-3, iStar (NCTech), SceneCam (Spheron VR AG), ScanStation C10 (Leica) and Focus3D X 330 (FARO), with each reporting to offer unique merits to an investigation. This can present difficulties for police services when considering the purchase and use of such technologies. With declining budgets, Police services do not have the time and resources to evaluate technology prior to its adoption. Thorough research evaluating the technology would allow Police services to make informed decisions about the adoption of technology which is fit for purpose and cost effective. This research explored panoramic technologies available to Police services and the considerations which organisations must account for prior to the adoption and integration into current standard operating procedures. An important adoption criteria is the accuracy and precision of capture and measurement of the technology’s hardware and software and these factors are essential factors for the successful integration of such equipment within the Criminal Justice System. The accuracy and precision of measurements taken using a 360o panoramic imaging system, ‘SceneCam’ and its complimentary content management system, ‘SceneCenter’ (Spheron VR AG) was examined and compared to traditional measurement methods. Measurements taken using the photogrammetry software were identified as being more reproducible than the any manual approach, and this offered flexibility with regards to the time and location of the documentation process in a crime scene

    PROSPECTIVE UPON MULTI-SOURCE URBAN SCALE DATA FOR 3D DOCUMENTATION AND MONITORING OF URBAN LEGACIES

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    Abstract. The investigation on the built urban heritage and its current transformations can progressively benefit from the use of geospatial data related to urban environment. This is even more interesting when urban design studies of historical and stratified cities meet the contribution of 4D geospatial data within the urban morphology researches, aiming at quickly and accurately identifying and then measuring with a spatial relationship, both localized transformation (volumes demolitions, addition, etc…) and wide-scale substantial modification resulting from urban zones of diversification spaces that incorporates urban legacies. In this domain, the comparison and analysis of multi-source and multi-scale information belonging to Spatial Data Infrastructures (SDI) organized by Municipality and Region Administration (mainly, orthoimages and DSM and digital mapping) are a crucial support for multi-temporal spatial analysis, especially if compared with new DSMs related to past urban situations. The latter can be generated by new solution of digital image-matching techniques applicable to the available historical aerial images. The goal is to investigate the amount of available data and their effectiveness, to later test different experimental tools and methods for quick detection, localization and quantification of morphological macro-transformation at urban scale. At the same time, it has been examined the opportunity to made available, with up-and-coming Mobile Mapping Systems (MMS) based on image- and range-based techniques, a rapid and effective approach of data gathering, updating and sharing at validated urban scales. The presented research, carried out in the framework of the FULL@Polito research lab, applies to urban legacies and their regeneration, and is conducted on a key redevelopment area in northern Torino, the Parco Dora, that was occupied by steel industries actively working up to 1992. The long-standing steel structures of the Ferriere FIAT lot have been refurbished and incorporated in the new urban park, generating a contemporary space with a new evolving urban fabric, and being integrated in the new updated geo-spatial databases as well.</p

    Spherical perspective

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    We survey the present state of spherical perspective, regarding both mathematical structure and drawing practice, with a view to applications in the visual arts. We define a spherical perspective as the entailment of a conical anamorphosis with a compact flattening of the visual sphere. We examine a general framework for solving spherical perspectives, exemplified with the azimuthal equidistant (“fisheye”) and equirectangular cases. We consider the relation between spherical and curvilinear perspectives. We briefly discuss computer renderings but focus on methods adapted to freehand sketching or technical drawing with simple instruments such as ruler and compass. We discuss how handmade spherical perspective drawings can generate immersive anamorphoses, which can be rendered as virtual reality panoramas, leading to hybrid visual creations that bridge the gap between traditional drawing and digital environments.info:eu-repo/semantics/publishedVersio
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