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Near-field X-ray ptychography has recently been experimentally shown to be able to recover a sample's complex valued transmission function from multiple near-field diffraction images, each with a lateral shift of the sample, in the monochromatic (single energy) case. In this paper, we show via numerical simulation that near-field X-ray ptychography is feasible with a polychromatic X-ray beam. Specifically,...
In this paper, we present a new type of trading card (called Stereo Cards) designed for a table-top Augmented Reality (AR) game environment. The main goal of Stereo Cards is to replace the current trading cards used in collectable card games such as Magic: The Gathering, YuGiOh, and Pokemon. The superior point of Stereo Cards is that they are computationally detectable and recognisable, e.g. they...
Ecologists commonly use photo-identification of individual animals to monitor the behaviour, state and health of a population, since it is a cost-effective technique that eliminates the need to physically capture and tag animals. With dolphins, the nicks and notches of the dorsal fin are typically used as the unique identifying features for each individual; however New Zealand common dolphins are...
Successful, timely diagnosis of neuropsychiatry diseases is key to management. Research efforts in the area of diagnosis of Alzheimer's disease have used various aspects of computer-aided multi-class diagnosis approaches with varied degrees of success. However, there is still need for more efficient and reliable approaches to successful diagnosis of the disease. This research used deep learning framework...
This paper examines some of the issues relating to the design and application of microfluidic channels not aligned perpendicularly to the optical axis of the image acquisition system. This technique finds potential application to the automation of lab-based cytometry tasks such as counting and classifying pollen or nematode eggs. Flow through such tilted microchannels will cause objects to move through...
This paper introduces a fiducial marker which favours accuracy over run-time performance. Its intended use is for creating ground truth for outdoor SLAM in GPS-denied environments. Rather than using only corners or edges for pose estimation, the marker has a radial sinusoid pattern which has a predictable appearance under perspective projection. A non-linear optimisation routine estimates the marker's...
X-ray free-electron lasers are new x-ray sources that are revolutionising high resolution molecular imaging. These sources produce extremely bright and extremely brief x-ray pulses that can overcome limitations of crystal growth and radiation damage in traditional protein x-ray crystallography. They introduce a new paradigm in diffraction imaging in which the specimen is destroyed, but not before...
In the last decade, consumer-grade waterproof digital cameras have been available more readily, allowing a more straight-forward application of underwater stereo photogrammetry, with the goal of obtaining high-quality DEMs. This paper presents our work into 3D river-bed reconstruction, using a GoPro Hero 3 black edition camera based on Tsai's calibration. The objective of this paper is to identify...
This paper investigates multi-focus image fusion methods in the context of microscope. Limited depth of field is one of the major limitations in microscopy. Objects which are thicker than the depth of field cannot be captured completely within one sharp image. The solution is to capture multiple images at different focus and fuse them to derive a single sharp image. Spatial domain and transform domain...
The determination of one's movement through the environment (visual odometry or self-motion estimation) from monocular sources such as video is an important research problem because of its relevance to robotics and autonomous vehicles. The traditional computer vision approach to this problem tracks visual features across frames in order to obtain 2-D image motion estimates from which the camera motion...
Soft machine tables are industrial robots with a soft, computer-controlled, deformable surface. They are designed to manipulate objects placed on the surface by changing the surface shape. The current control approaches for the soft actuators embedded in the surface layer are open-loop, because appropriate sensors have not been developed, yet. In this report, we propose a solution based on an array...
Wavefront sensors measure specific properties, either in the optical pupil plane or indirectly at the image plane; the former uses incident light in the pupil of an optical system, whereas the later employs one or more focal plane sensors to recover the wave front. Phase perturbations, in the form of low-order Zernike coefficients, e.g., defocus (Z5) in this case, are introduced using a bimorph deformable...
Image feature-based ego-motion estimation has been dominating the development of visual odometry (VO) visual simultaneously localisation and mapping (V-SLAM) and structure-from-motion (SfM) for several years. The detection extraction or representation of image features play crucial roles when solving camera pose estimation problems in terms of accuracy and computational cost. In this paper we review...
We present a method of extracting utility poles from variable density points clouds captured using a vehicle-based LIDAR. Our method slices a point cloud into discrete horizontal regions and project each of the points contained within a region onto a horizontal plane. We then search each of the horizontal planes for structures that resemble the cross section of vertical poles. After we have constructed...
Situated Visualization techniques are visualization techniques that provide a presentation of information within its spatial context. Situated Visualization techniques have several advantages compared to traditional visualization techniques with the biggest advantage being providing the spatial relationship between data and the actual environment. However, Situated Visualization techniques are also...
Texture feature is an important feature descriptor for many image analysis applications. The objectives of this research are to determine distinctive texture features for crowd density estimation and counting. In this paper, we have comprehensively reviewed different texture features and their different possible combinations to evaluate their performance on pedestrian crowds. A two-stage classification...
Autonomous on-road vehicles or vision-based driver assistance benefit from free-space analysis. This paper evaluates the accuracy of free-space detection in stereo and monocular vision on KITTI benchmark data. Such an evaluation of low-level computer vision algorithms is, for example, also necessary as free-space analysis is recently becoming an important module for designing vehicle test beds. The...
In this paper, by using geodesic distance and compactness prior, we present some effective improvements concerning the two important aspects of diffusion-based methods: the construction of the diffusion matrix and seed vector. First, based on the geodesic distance, we construct a 2-layer knn graph. Compared with the most frequently used 2-layer neighborhood graph, our graph does not only effectively...
Programming assignments are a popular assessment tool in Computer Science education. The value of such assignments depends on how fast and detailed formative feedback is given. This is often a problem due to large class sizes and the cost and difficulty of finding qualified markers. Research on automatic assessment and feedback tools has concentrated on code analysis and correct usage of programming...
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