Building a dense and accurate environment model out of range image data faces problems like sensor noise, extensive memory consumption or computation time. We present an approach which reconstructs 3D environments usi...
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Building a dense and accurate environment model out of range image data faces problems like sensor noise, extensive memory consumption or computation time. We present an approach which reconstructs 3D environments using a probabilistic occupancy grid in real-time. Operating on depth image pyramids speeds up computation time, whereas a weighted interpolation scheme between neighboring pyramid layers boosts accuracy. In our experiments we compare our method with a state-of-the-art mapping procedure. Our results demonstrate that we achieve better results. Finally, we present its viability by mapping a large indoor environment.
This paper proposes to integrate probabilistic latent semantic analysis (PLSA) and Laplacian Eigenmaps (LE) for broadcast news story segmentation. PLSA can address synonymy and polysemy problems by exploring underlyin...
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This paper proposes to integrate probabilistic latent semantic analysis (PLSA) and Laplacian Eigenmaps (LE) for broadcast news story segmentation. PLSA can address synonymy and polysemy problems by exploring underlying semantic relations beneath the actual occurrences of words. LE can provide a data transformation with the advantage of preserving the original temporal structure of sentence cohesive *** adopt PLSA statistics to replace term frequency as the representation of sentences and measure their connective strength. LE analysis is then performed on the connective strength matrix so that the sentence relations becomes geometrically evident for discriminating different stories. A dynamic programming (DP) algorithm is used for story boundary identification. Experiments show that the proposed method achieves superior story segmentation performances with the highest F1-measure of 0:7536 on TDT2 Mandarin BN corpus.
In this paper, a novel unified channel model framework is proposed for cooperative multiple-input multiple-output (MIMO) wireless channels. The proposed model framework is generic and adaptable to multiple cooperative...
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In this paper, a novel unified channel model framework is proposed for cooperative multiple-input multiple-output (MIMO) wireless channels. The proposed model framework is generic and adaptable to multiple cooperative MIMO scenarios by simply adjusting key model parameters. Based on the proposed model framework and using a typical cooperative MIMO communication environment as an example, we derive a novel geometry-based stochastic model (GBSM) applicable to multiple wireless propagation scenarios. The proposed GBSM is the first cooperative MIMO channel model that has the ability to investigate the impact of the local scattering density (LSD) on channel characteristics. From the derived GBSM, the corresponding multi-link spatial correlation functions are derived and numerically analyzed in detail.
Three-dimensional (3D) ultrasound (US) is increasingly being introduced in the clinic, both for diagnostics and image guidance. Obtaining 3D volumes with 2D US probes is a two-step process. First, a positioning sensor...
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Three-dimensional (3D) ultrasound (US) is increasingly being introduced in the clinic, both for diagnostics and image guidance. Obtaining 3D volumes with 2D US probes is a two-step process. First, a positioning sensor must be attached to the probe;second, a reconstruction of a 3D volume can be performed into a regular voxel grid. Various algorithms have been used for performing 3D reconstruction based on 2D images. In this paper, we propose a new Hole-filling algorithm using Distance Weight interpolation, and we also apply it to generate the volume in our image-guided for surgical robot. First, the ultrasound frames and position information are compounded into a 3D volume using the Bin-filling method. Then, the Hole-filling method is used to repair gaps in the volume. We define the empty voxels by sorting the neighboring voxels into three parts, and averaging them to obtain the value to fill the empty voxels according to distance weighted. The empty voxel estimation can be improved by thresholding the range width of its neighboring voxels and adjusting it to the average values. The method is tested on a Hole-manipulated volume derived from a cropped 3D ultrasound volume of chicken kidney. Our method shows improved result compared to several tested existing methods, including voxel nearest neighbour(VNN) and spline function interpolation.
By analyzing the numerical characteristics of impulse noise images, in order to resolve spreading-noise problem resulted from dilating and eroding images base on mathematical morphology, an algorithm of dilating and e...
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In order to resolve the problem of skew phenomenon in the handwritten document image during the scanning process, a new skew angle detection algorithm based on maximum gradient difference as well as Hough transform wa...
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By analyzing the numerical characteristics of impulse noise images, in order to resolve spreading-noise problem resulted from dilating and eroding images base on mathematical morphology, an algorithm of dilating and e...
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By analyzing the numerical characteristics of impulse noise images, in order to resolve spreading-noise problem resulted from dilating and eroding images base on mathematical morphology, an algorithm of dilating and eroding color impulse noise images based on mathematical morphology is proposed. The result of the experiment demonstrates that the new algorithm has same effect as traditional algorithm of dilating and eroding images, but also suppresses impulse noise.
The popular formulas of evaluating the similarity of digital watermarks have serious drawbacks: when the similarity degree is 1, the watermarks are not unique. This paper firstly analyzes the drawbacks in the popular ...
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The objective of semantic segmentation in microscopic images is to extract the cellular, nuclear or tissue components. This problem is challenging due to the large variations of these components features (size, shape,...
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The objective of semantic segmentation in microscopic images is to extract the cellular, nuclear or tissue components. This problem is challenging due to the large variations of these components features (size, shape, orientation or texture). In this paper we improve the technique presented in [17] used to identify the epithelial nuclei (crypt) against interstitial nuclei in microscopic images taken from colon tissues. In the proposed enhanced approach, the crypt inner boundary is detected using the closing morphological pyramid instead of morphological hierarchy. The outer crypt border is determined by the epithelial nuclei, overlapped by the maximal isoline of the inner boundary. The use of sampling in building the pyramid offers computational efficiency, reduces the amount of used memory, increase the robustness and preserve the quality results. An analysis of the two approaches is performed considering the number of pixels processed to create each level. Also the relation between the levels of the hierarchical structures is established.
Locating an iris is important in an iris recognition system. Previous studies have shown good performance when an iris image is clear. However, if an iris image is occluded by eyelids, eyelashes and reflection, the ac...
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Locating an iris is important in an iris recognition system. Previous studies have shown good performance when an iris image is clear. However, if an iris image is occluded by eyelids, eyelashes and reflection, the accuracy and robustness of localization will decrease significantly. This paper proposed a new algorithm to locate an iris in a coarse-to-fine manner: firstly, a modified radial symmetry transform was used to find the possible pupil region; secondly, an enhanced circular integro operator was adopted to obtain the precise iris location. Experimental results on CASIA V3.0 iris database showed that proposed algorithm has a more accurate and robust performance than the previous methods, especially when occlusion of eyelids, eyelashes and reflection occurred. A real-time system was able to be achieved by the coarse-to-fine strategy as well.
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