As the Harris detector can produce false and unstable corners, and obtained matching points have different accuracies in aerial video registration, an aerial video registration algorithm using optimal gradient filters...
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As the Harris detector can produce false and unstable corners, and obtained matching points have different accuracies in aerial video registration, an aerial video registration algorithm using optimal gradient filters and projective invariant was proposed. Firstly, a Harris detector based on optimal gradient filters was presented to determine the location of corners, and the locally most stable points were selected to be matching points. Then, the Delaunay triangulation was used to perform the initial matching. Finally, the most "useful" matching points that best satisfied the cross-ratio invariant were presented to estimate the geometry transformation and finish the image registration. Experiment results show that the proposed method by the optimal gradient filters and cross-ratio invariant can realize the registration between the frames, and the average geometric fidelity error is 0.869 for 8 sets of the unmanned video sequences with a resolution of 320 pixel×240 pixel. The method can capture moving objects effectively.
The frequency domain electromagnetic method has already been widely used for tomographic imaging or electromagnetic well logging. However, different from open hole logging, the metal casing existing in production well...
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The frequency domain electromagnetic method has already been widely used for tomographic imaging or electromagnetic well logging. However, different from open hole logging, the metal casing existing in production well logging has a strong shielding effect on the electromagnetic waves, thus bringing some difficulties to the application of the frequency domain electromagnetic method in production well logging. According to the relation of the field source geometry to the ring around the mandrel, the general expressions of frequency domain electromagnetic responses in axially symmetrical layered conductive medium are deduced. The propagation effects caused by the low-frequency electromagnetic waves in cased hole are also analyzed. The distribution curves of eddy current density and magnetic flux density along the radial direction in the mandrel indicate that the eddy loss within the mandrel is proportional to the transmission signal frequency and the mandrel conductivity. The secondary field responses of different casing materials show that the transmission frequency has an important effect on the ability of electromagnetic waves penetrating the metal casing. The transmission frequency should be ultra-low in order to enable the electromagnetic signal to penetrate the casing easily. The numerical results of frequency responses for different casing physical parameters show that the casing thickness has a significant impact on the choice of the transmission frequency. It is also found that the effect of the casing radius on the transmission frequency can be neglected.
This paper proposes a novel method for content-based image retrieval based on interest points. Interest points are detected from the scale and rotation normalized image. Then the normalized image is divided into a ser...
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This paper proposes a novel method for content-based image retrieval based on interest points. Interest points are detected from the scale and rotation normalized image. Then the normalized image is divided into a series of sector sub-regions with different area according to the distribution of interest points. With robustness to the image's rotation, scale and translation, local features of every sector sub-region are extracted to describe the image and make the similarity measure. In the relevant feedback phase, images are regarded as multi-instance (MI) bags, and the MI learning algorithm is employed to compute the target image feature. Finally, the similarity is recalculated. Experimental results show that our method can effectively describe the image, and obviously improve the average retrieval precision.
Content-Based Copy Detection(CBCD) is a heated research area.A variety of features are extracted and applied extensively to improve the performance of CBCD systems.A novel scheme which adopts 3-Dimensional SIFT Descri...
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Content-Based Copy Detection(CBCD) is a heated research area.A variety of features are extracted and applied extensively to improve the performance of CBCD systems.A novel scheme which adopts 3-Dimensional SIFT Descriptors(Paul Scavenger, 2007) based on the innovative dynamic tunnels is proposed in this *** algorithm is aim to reach a proper balance between efficiency and *** results indicate that the algorithm achieves an accuracy match with inexpensive computational cost.
A new model-based human body tracking framework with learning-based theory is introduced in this *** propose a variable structure multiple model (VSMM) framework to address challenging problems such as uncertainty of ...
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A new model-based human body tracking framework with learning-based theory is introduced in this *** propose a variable structure multiple model (VSMM) framework to address challenging problems such as uncertainty of motion styles,imprecise detection of feature points,and ambiguity of joint *** human joint points are detected automatically and the undetected points are estimated with Kalman *** motion models are learned from motion capture data using a ridge regression *** model set that covers the total motion set is designed on the basis of topological and compatibility relationships,while the VSMM algorithm is used to estimate quaternion vectors of joint *** using real image sequences and simulation videos demonstrate the high efficiency of our proposed human tracking framework.
In the smoky, foggy, hazy and other harsh outdoor conditions, scene image captured is severely degraded by the scattering of atmospheric particles. Based on atmospheric scattering model, degraded image in this paper i...
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A fast moving object detection algorithm is presented based on sorted block's compensated difference. First, global motion estimation is applied based on feature points matching. The iteration of minimum sum of pl...
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Synchronization and pinning control of complex networks is to regulate the agents' behavior and improve network performance. In this article, we review some recent developments in pinning control. Stability algori...
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This paper proposed a H∞ based controller design method for MIMO system. We use the bound real lemma to design the controller when the reference model is given. The BMI (Bi-linear Matrix Inequality) problem is turned...
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