Applied Mechanics and Materials Vols. 719-720

Abstract: The paper analysis mean filter, median filter and morphology filter. The paper studied order morphology theory and its filter character. Based on this, the paper proposed multi-scale and multi-structure filter algorithm based on order morphology. The result of simulation shows that the algorithm can not only keep the edge and detail of medical image but also can enhance the contrast of recovery image.

Abstract: The image segmentation is very important in medical image processing. The paper studies the watershed segmentation, and over-segmentation is the main problem of watershed. Based on this, the paper proposed an improved watershed medical image segmentation method. And the corresponding simulation is done and the result show that the method can resolve the over-segmentation of watershed and can achieve good segmentation.

Abstract: The purpose of multiple biometric fusion is to improve the recognition performance by utilizing their complementary. In this paper, the feature fusion recognition method of multi-view face and gait in video is studied, and a adaptive decision fusion method is proposed. The results showed that the adaptive fusion features carry the most discriminating power compared to any individual biometric and other static fusion rules like Max and Sum.

Abstract: In order to extract useful information of underwater acoustic signals from noise, preprocessing steps are unavoidable. In view of trend and transient pulse interference exited in the original data inevitability, morphological filter method is applied and analyzed in this paper. Data processing results show that the morphological filter method is superior to the traditional filter method.

Abstract: Due to the fact that the range history of bistatic synthetic aperture radar (SAR) doesn’t follow the hyperbolic function, the accurate analytical spectrum of bistatic SAR cannot be obtained directly by the principle of stationary phase (POSP). In this paper, we approximate the range history of bistatic SAR by the hyperbolic function, and propose a novel two-dimensional (2-D) analytical spectrum model for bistatic SAR. The huge advantage of this novel 2-D analytical spectrum is that the equivalent radial velocity of any scatter point in the observed scene, with respect to the radar platform, is not only the same but also invariant with the equivalent range. Further, based on this novel spectrum model, the wavenumber domain algorithm (WDA) could be applied to image the whole observed scene. Finally, the simulation and realistic data imaging results also validate that this novel spectrum model is correct and effective.

Abstract: In recent years, chaos-based image encryption technologies have been widely studied to meet the increasing demand for real-time secure image transmission applications. To overcome the drawbacks of small key space and weak security in many existing schemes based on low-dimensional chaotic maps, this paper suggests a security improved scheme with a permutation-diffusion architecture. In the permutation stage, baker map is employed to shuffle the pixel positions. In the diffusion stage, the value of each pixel is altered by using a key stream derived from hyperchaotic system. Compared with ordinary chaotic systems, hyperchaotic systems, with more complex dynamical behaviors and number of system variables, offer greater potential for secure cryptosystem construction. Extensive security analysis has been performed on the proposed scheme, including the most important ones like key space analysis, statistical analysis and key sensitivity, which has demonstrated the satisfactory security of the proposed scheme.

Abstract: In order to improve the accuracy of the phase and amplitude of acceleration integration results, a new method to transform acceleration signal into displacement was presented which combines Empirical Modal Decomposition (EMD) adaptive filtering with FFT based frequency domain integration. The acceleration signal is decomposed by EMD into n IMF, and by certain rules, the number of IMF pertaining high frequency (h) is determined, and the h IMF are adaptively filtered to cancel noises. After that, the FFT transform is applied to the n processed IMF, frequency domain integration is done, and finally the displacements time series is obtained by IFFT. Simulation shows that this acceleration signal processing method is better than the pure frequency domain integration transformation.

Abstract: In this paper, we present a leaf vein extracting algorithm frame which deals with contour and interior vein by employing different methods. The interior vein extraction method based on gray scale processing, mathematical morphology and processing in details is presented. We apply gray-scale morphology to process the image and extract the vein information. Through the analysis of the image information, processing in details is adopted to clear the information on the other tissues and insignificant veins. The extracted significant interior vein is overlaid with the leaf contour extracted through edge detection by pixel union operation. Experiment results show the effectiveness of the proposed method.

Abstract: Synthetic Aperture Radar (SAR) has become one of the important means for the ocean remote sensing detection of oil spills. The existing SAR image segmentation method has the issues of edge blur, poor contrast, non-uniform intensity image, so the segmentation effect is not ideal. This paper presents a variational level set SAR image of oil spill detection method based on fuzzy clustering. First of all, apply the threshold method on initial segmentation of the original SAR image to transform the initial segmented image as fuzzy clustering. Secondly, introduce the clustering results into the initial level set function to achieve the initial contour. Finally, add fuzzy clustering model in the level set energy function to complete the level set evolution process and get the final segmented image. This paper uses the threshold segmentation results to achieve the initialization of the variational level set function profile. In theory, it could improve the level set method for efficiency, and reduce the wrong segmentation phenomenon. The experimental results show that the SAR image segmentation method of oil spill has good segmentation qualities and is suitable for the edge complex image segmentation.

Abstract: In block transform based coding, coefficients scanning plays an important role in improving compression performance. A good scanning method has great potential to remove statistical redundancy, as it can apply an energy compaction coefficients vector. In this paper, a mode-dependent (MD) coefficients scanning method is introduced, with the idea of reducing the overall bit rate by adopting side information to coding mode indexes. In the experiment, we design 128 MD scanning tables according to the DCT coefficients energy distribution, and explore the relationship between the number of scanning table used and the bit saving in image coding. The results provide reference to choose scanning modes by considering the trade-off of the increasing of side information and the decrease of data redundancy.