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Image stitching and object insertion in the gradient domainSevcenco, Ioana Speranta 20 December 2011 (has links)
In this thesis, the applications of image stitching and object insertion are considered
and two gradient based approaches offering solutions are proposed. An essential
part of the proposed methods is obtaining an image from a given gradient data set.
This is done using an existing Haar wavelet based reconstruction technique, which
consists of two main steps. First, the Haar wavelet decomposition of the image to
be reconstructed is obtained directly from a given gradient. Second, the image is
obtained using Haar wavelet synthesis. In both stitching and object insertion applications
considered, the gradient from which the image must be reconstructed is a
non-conservative vector field and this requires adding an iterative Poisson solver at
each resolution level, during the synthesis step of the reconstruction technique. The
performance of the reconstruction algorithm is evaluated by comparing it with other
existing techniques, in terms of solution accuracy and computation speed.
The proposed image stitching technique consists of three main parts: registering
the images to be combined, blending their gradients over a region of interest and
obtaining a composite image from a gradient. The object insertion technique considers
the images registered and has two main stages: gradient blending of images in a region
of interest and recovering an image from the gradient.
The performance of the stitching algorithm is evaluated visually, by presenting the
results produced to combine images with varying orientation, scales, illumination, and
color conditions. Experimental results illustrate both the stitching and the insertion
techniques proposed, and indicate that they yield seamless composite images. / Graduate
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Foreign object insertion in sexual homicide cases : an exploratory studyLabuschagne, Gerard Nicholas 22 August 2008 (has links)
Foreign object insertion into the vagina of a murder victim is a rare occurrence. When it is encountered it is often seen as an indicator of a sexual murder, or regarded for signature analysis purposes. Due to its rare occurrence it is often only documented in literature in case-study form. In this research seventeen cases of vaginal foreign object insertion were analysed, by far the largest study of this occurrence to date. Cases were only included in the research if the object was still in the vagina when the body was discovered. The research set out to determine the typical victim profile, crime-scene actions, and offender profile, with the intention of assisting in the profiling of these crimes in the future. There were distinct differences amongst the victims in terms of race, occupation, time of death, cause of death, circumstances and area of the crimes. Only six of the seventeen crimes had been solved, yet amongst the eight known offenders certain common characteristics were observed. / Dissertation (MA)--University of Pretoria, 2007. / Social Work and Criminology / unrestricted
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