Browsing by Author "Samarawickrama, J"

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    item: Conference-Abstract
    Appearance based tracking with background subtraction
    (2014-06-24) Jayamanne, DJ; Samarawickrama, J; Rodrigo, BKRP
    Grouping the detected feature points traditionally requires the storage of long corner tracks. The traditional method does not permit to arrive at a decision to cluster the feature points based on a frame by frame basis. This paper presents a method to group the feature points directly into objects using the most recent 20 frames. The detected corner features are validated and clustered based on two approaches. When objects move in isolation, an EM algorithm is used to cluster and every object is detected and tracked. When objects move under partial occlusion, the corner features are clustered based on an agglomerative hierarchical clustering approach. A probabilistic framework has also been applied to determine the object level membership of the candidate corner features. A novel foreground estimation algorithm with an accuracy of 98% based on color information, background subtraction result and detected corner features is also presented.
  • Thumbnail Image
    item: Conference-Abstract
    Appearance based tracking with background subtraction
    Jayamanne, DJ; Samarawickrama, J; Rodrigo, R
    Grouping the detected feature points traditionally requires the storage of long corner tracks. The traditional method does not permit to arrive at a decision to cluster the feature points based on a frame by frame basis. This paper presents a method to group the feature points directly into objects using the most recent 20 frames. The detected corner features are validated and clustered based on two approaches. When objects move in isolation, an EM algorithm is used to cluster and every object is detected and tracked. When objects move under partial occlusion, the corner features are clustered based on an agglomerative hierarchical clustering approach. A probabilistic framework has also been applied to determine the object level membership of the candidate corner features. A novel foreground estimation algorithm with an accuracy of 98% based on color information, background subtraction result and detected corner features is also presented.
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    item: Conference-Abstract
    Hardware implementation of motion blur removal
    (2011) Chandrapala, T; Cabral, A; Sameera, T; Ahangama, S; Samarawickrama, J
    Motion Blur due to the relative motion between the camera and object can seriously degrade image quality. We present an FPGA based blur detection and correction algorithm which is implemented on lop of a configurable soft-processor based architecture. The system consists of two main modules. The blur detection module identifies the blur length and angle, and the restoration module uses regularized inverse filtering to remove the blur. The Processing algorithms are implemented as separate cores on the FPGA fabric where the soft processor core is only used for managing system configuration. The system can achieve a frame rate of 15fps for a 720p HD video strea
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    item: Conference-Abstract
    Real time stereo vision based on biologically motivated algorithms using GPU
    (2011) Chandrapala, T; Samarawickrama, J
    Although many recent stereo vision algorithms have been able to create disparity maps with high accuracy, because of the sequential nature it is difficult to adopt them for real time applications. Biologically motivated algorithms involving Gabor filters demonstrate inherent parallelism and could be effectively implemented in parallel hardware such as Graphics Processing Units(GPUs). We present a real time stereo vision algorithm based on Gabor filters which effectively use the memory hierarchy and the threading resources of the Graphics Processing Unit(GPU). Since the 2D filtering process is a critical activity which takes upto 50% of the total time to create the disparity map, we evaluate the GPU implementation of three filtering methods. Using the optimal filtering method out of them, we were able to achieve a frame rate of 76 fps for a 512x512 image stream on a NVIDIA GTX 480 GPU, and a I70x speed-up compared to the conventional CPU based implementation.
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    item: Thesis-Full-text
    Underground PVC/PE water pipe detection system
    Sampath, RADK; Samarawickrama, J
    With the development of technology, a lot of underground cables, wires and pipes are buried underneath. There is lot of equipment to detect metal objects, but limited equipment to detect non-metallic objects which are very expensive. The objective of the research was to develop a low cost equipment to detect underground non-metallic pipes in either horizontal or vertical placed positions. Since this type of detection cannot be done using electromagnetic locators, an acoustic method is used to generate continuous-wave (CW) acoustic signal, which is then injected and transmitted throughout the pipe. Afterwards, the transmitted signals were captured using a seismic sensor. The data gathered was used to determine the location of the buried non-metallic pipes. The received signals were amplified, filtered and then differentiated using cross-correlation method. As a result, a reduction in unwanted signals was observed, thereby accurate transmitted signals from the actual underground pipe was captured