Texture gradient based watershed segmentation (original) (raw)

Multiple Object Tracking Using Particle Filters

2006

MULTIPLE OBJECT TRACKING USING PARTICLE FILTERS Publication No. Hwangryol Ryu, MS The University of Texas at Arlington, 2006 Supervising Professor: Manfred Huber We describe a novel extension to the Particle Filter algorithm for tracking multiple objects. The recently proposed algorithms and the variants for multiple object tacking estimate multi-modal posterior distributions that potentially represent the multiple peaks (i.e., multiple tracked objects). However, the specific state representation does not demonstrate creation, deletion, and more importantly partial/complete occlusion of the objects. Furthermore, the weakness of the Particle Filter such that the representation may increasingly bias the posterior density estimates toward objects with dominant likelihood makes the multiple object tracking algorithms more difficult. To circumvent a sample depletion problem and maintain the computational complexity as good as the mixture Particle filters under certain assumptions (1) tar...

Contour tracking of contaminant clouds with sequential Monte Carlo methods

2008 IEEE International Conference on Acoustics, Speech and Signal Processing, 2008

Contour tracking for a single source emission is addressed in this paper. This problem is solved by estimating the contour boundary positions using a set of particle filters. The use of Sequential Monte Carlo techniques enables the tracking to performed when the measurements are noisy and the tracking results also includes the estimation uncertainty. The proposed technique is illustrated for a SCIPUFF generated single emission scenario and simulation experiments showed the successful tracking throughout the tracking period.

Statistical Multiscale Image Segmentation via Alpha-Stable Modeling

2007 IEEE International Conference on Image Processing, 2007

This paper presents a new statistical image segmentation algorithm, in which the texture features are modeled by Symmetric Alpha-Stable (SαS) distributions. These features are ef ciently combined with the dominant color feature to perform automatic segmentation. First, the image is roughly segmented into textured and nontextured regions using the Dual-Tree Complex Wavelet Transform (DT-CWT) with the subband coef cients modeled as SαS random variables. A multiscale segmentation is then applied to the resulting regions, according to the local texture characteristics. Finally, a novel statistical region merging algorithm is introduced by measuring the Kullback-Leibler distance (KLD) between estimated SαS models for the neighboring segments. Experiments show that our algorithm achieves superior segmentation results in comparison with existing state-of-the-art image segmentation algorithms.

9th International Conference on Transparent Optical Networks, 2007 (ICTON '07) Rome, Italy

International Conference on Transparent Optical Networks, 2007

This paper presents 2D FDTD modelling of a disk resonator that could be used as a disk laser. Results are shown for mode spacing and good agreement with a simple Whispering Gallery Mode model is observed. The influence of direct coupled waveguides on modal behaviour is studied and a large reduction in cavity Q is observed.

A Novel H.264/AVC Based Multi-View Video Coding Scheme

2007 3DTV Conference, 2007

This paper investigates extensions of H.264/AVC for compressing multi-view video sequences. The proposed technique resorts frames of sequences captured by multiple cameras looking at a person in a scene from different views and generates a single video sequence. The multi-frame referencing property of the H.264/AVC, which enables exploitation of the spatial and temporal redundancy contained in the multi-view sequences, is employed to implement several modes of operation in the proposed coding algorithm. To evaluate the performance of the proposed coding technique at different modes of operations, five multi-view video sequences at different frame rates were coded using the proposed and the simulcast H.264/AVC coding schemes. Experiments show the superior performance of the proposed coding scheme when coding the multi-view sequences at low and up to half of the original frame rates.

Rotationally invariant texture based features

Proceedings 2001 International Conference on Image Processing (Cat. No.01CH37205)

Content-based retrieval is ultimately dependent on the features used for the annotation of data and its efficiency is dependent on the invariance and robust properties of these features. For texture based features an important form of invariance is rotational invariance. In this paper novel rotationally invariant texture based features are introduced that are extracted from a Polar Fourier Transform (PFT). The PFT is similar to the Discrete Fourier Transform in two dimensions but uses transform parameters radius and angle rather than the Cartesian coordinates. The PFT is discretised appropriately across the angular and radial frequency space with the transform magnitudes forming the rotationally invariant features. These features although rotationally invariant, capture the angular distribution together with the radial distribution of frequency within texture. Preliminary results show the method to give better results than rotationally variant and invariant Gabor filter schemes.

Hardware architecture for lossless image compression based on context-based modeling and arithmetic coding

2007 IEEE International SOC Conference, 2007

In this paper we present a novel hardware architecture for context-based statistical lossless image compression, as part of a dynamically reconfigurable architecture for universal lossless compression. A gradient-adjusted prediction and context modeling algorithm is adapted to a pipelined scheme for low complexity and high throughput. Our proposed system improves image compression ratio while keeping low hardware complexity. This system is designed for a Xilinx Virtex4 FPGA core and optimized to achieve a 123 MHz clock frequency for real-time processing.

Simulation and measurement of quasi-optical multipliers

IEEE Transactions on Microwave Theory and Techniques, 2001

The lumped-element finite-difference time-domain method is used to analyze quasi-optical multipliers based on diode loaded slot antennas. The method is validated firstly for a passive microstrip-fed structure then for the diode loaded case in both small-and large-signal regimes. The diode model is separately validated using a series diode mounted on a microstrip line. Input return loss and radiation patterns show good agreement with measurements and the concept of effective conversion loss is introduced and results show reasonable agreement between measurement and simulation. A new diode arrangement is introduced where dual offset diodes are placed in the slot instead of the conventional central diode. The diode position can then act as an extra design parameter. The performance of the two structures has been compared; currently best performance is still obtained for the central-diode structure. Finally, a fully quasi-optical structure is simulated with plane-wave excitation. Central and dual-diode structures are again compared and the diode position and input plane-wave field strengths are optimized. Slot voltage distributions, radiation patterns, and effective quasi-optical conversion losses are presented.