Applied Mechanics and Materials Vols. 239-240

Abstract: This paper presents two novel approaches for palmprint verification by scene match- ing. In a sense, the process of palmprint verification can be regarded as matching one palmprint template with another palmprint sample taken under conditions of different illumination, sensor pose geometry, or types of sensor, and making a decision of whether they belong to the same person or not. Enlightened by the idea of scene matching algorithms, two efficient approaches by scene matching are presented for palmprint verification. A sub-image from the user’s training palmprint is intentionally extracted, and stored as a template. In the verification stage, the sample image is directly matched with the template without the step of ROI (Region of Interest) extraction. Whether the sample image and the template are from the same person or not is decided by their matching scores. Experimental evaluation results on two databases clearly demonstrate the effectiveness of the proposed approaches.

Abstract: Wavelet packet transform (WPT) and common spatial pattern (CSP) are two commonly used methods for feature extraction in brain-computer interfaces. In this paper, a new feature extraction method was proposed that was based on the combination of WPT and CSP. The raw EEG signals were band pass filtered between 8 and 30Hz, then the filtered signals were subject to WPT and reconstruction, and finally the reconstructed signals were spatially filtered by CSP algorithm. The proposed algorithm was applied to six data sets recorded during BCI experiments based on motor imagery. The results showed superior classification performance, thus verifying the feasibility and validity of the algorithm.

Abstract: When car is in the process of high-speed, the faults caused by tire pressure anomalies are the most worried and difficult to prevent for all drivers. It is one of the important reasons for the sudden traffic accidents. Tire pressure related to ride comfort, fuel consumption, tire wear and vehicle safety, so tire pressure’s monitoring has been one of the important research directions in the safe driving of vehicle. The anomalies of tire pressure made the vehicles appear to tilt and shorten the distance between rim centres and the ground. Using image technology can detect intuitively and fast. This paper measures the dynamic tire pressure based on image processing technology. The vehicles tires goal was extracted by three image differences. After morphological processing, it used three methods to make comprehensive analysis and judgement of whether the tire pressure is normal, to realize the automation and intelligence. This method had realized real-time non-contact detection for dynamic tire pressure, which has extended significance to popularize.

Abstract: A finger vein image quality assessment method is based on both the human visual characteristics and finger vein image characteristics captured by the use of contactless and near infrared rays. We present an HSNR (signal to Noise ratio based on human visual system) finger vein image quality evaluation index by simulating the human visual system, and integrating the HSNR with effective area score, finger shifting score and contrast score to obtain the total image quality score of the finger vein image. Experimental results demonstrate that the proposed method is consistent with subjective assessment by humans, and thus can be used to describe the visual perception of the image effectively.

Abstract: Bullet mark comparison is one of the key techniques in the discovery of evidences. A bullet mark comparison method was presented in this paper. First the bullet marks data are gathered according to generally used equipment. There are many coarse data cannot be used in matching process, so a preprocessing on the raw data is need. A statistics modeling is set up to construct a cost function, which can be used to evaluation choose of error until the cost function get minimum value. Experiment showed this comparison method can solve comparison problems of bullet mark.

Abstract: To improve the estimation accuracy of non-data-aided (NDA) signal-to-noise ratio (SNR) estimators at low SNR value, A novel estimation technique for binary phase-shift keying and quadrature phase-shift keying signals in complex additive white Gaussian noise channel is proposed. The mathematical relation between SNR and the ratio of two simple statistical computations is derived, then SNR is determined by looking up a table. Its accuracy surpasses other NDA estimators, approaching closely to the Cramer-Rao lower bound at SNR > 5dB.

Abstract: It is urgent to study how to effectively identify color of moving objects from the video in the information era. In this paper, we present the color identification methods for moving objects on fixed camera. One kind of the methods is background subtraction that recognizes the foreground objects by compare the difference of pixel luminance between the current image and the background image at the same coordinates. Another kind is based on the statistics of HSV color and color matching which makes the detection more similar to the color identification of the human beings. According to the experiment results, after the completion of the background modelling, our algorithm of background subtraction, statistics of the HSV color and the color matching have strong color recognition ability on the moving objects of video.

Abstract: Contour initialization is a big problem of the active contour model. Using the continuous features of the three-dimensional medical image, this paper proposes an initial contour prediction model. There are some changes in the boundary contours of the same object. We attribute these changes to continuous translation and similar deformation, and quantify into the centroid displacement and displacement of the point in the direction of Normal. The curve fitting method is used to predict the centroid displacement and the displacement of the points of the contours, which can provide more accurate prediction of changes in the contour. By predicting the initial contour, we have solved the contour initialization problem of the parametric active contour with external force using vector field convolution.

Abstract: Transmission fluctuation spectrometry (TFS) is a new method for particle analysis based on the statistical fluctuations of a transmission signal. With simple optical arrangement and easy operation, the method can be applied to real-time, online measurements. The transmission signal with fluctuations are analyzed by using 1st order band-pass filters, and the experimental data in the frequency domain are obtained. The particle size distribution (PSD) and particle concentration are extracted from the experimental data with the modifed Chahine interations. It is found that the measurements using band-pass filters are of better resolution in the PSD than those with low-pass filters.

Abstract: We proposed improved wavelet network and applied it to image compression. Activation function was selected automatically from three wavelet basis functions based on the effect of image compression. The three given wavelet basis functions were Morlet, Mexican-Hat and Different Of Gauss(DOG) wavelet basis functions respectively. The results show that the improved wavelet networks method is better than general wavelet networks in image compression.