International Journal of Intelligent Engineering and Systems

8

Authors: BaozhuWang, Xiuying Chang, Cuixiang Liu

This paper presents the procedures of face segmentation in the color image based on skin detection through the establishment of skin model and the segmentation of skin region. Firstly, in order to reduce the effect of factors on the segmentation of face region, a method for compensating the color of input images is used to alleviate the interferences from bad illuminating conditions. Secondly, Gaussian model about skin information is established which can be used to detect skin pixels in color images and transform color images to gray-scale images. Thirdly, a new algorithm of Otsu is used to find out the skin regions in binary images. Finally, mathematical morphology operator and prior knowledge are used to find out the face regions and discard regions that are similar to the skin in color. This method can deal with various sizes of faces, different illumination conditions, diverse poses and changeable expressions. In particular, the scheme significantly increases the execution speed of the face segmentation algorithm in the case of complex backgrounds. The experiments show that this method reduces the computation of the procedure, and at the same time improves the detection speed and efficiency.

8

Authors: Yueqiu Jiang, Hongwei Gao, Lei Jin

It is a fundamental problem to calculate target area in pattern recognition. This paper compares the common algorithms for calculating target area, and analyzes the advantages and disadvantages of these algorithms. In order to overcome the shortcomings of common algorithms and obtain a more simple and effective algorithm, the knowledge of mathematical morphology is studied. Then, a new algorithm based on an improved algorithm of contour extracting for calculating target area is proposed. The algorithm will obtain the coordinate and type information of the contour points by extracting the contour of the target region and calculate the target area based on weighting summation of the abscissa of contour point. At last, detect whether the algorithm is effective and practical or not by comparing with several common algorithms. The result of experiment shows that this algorithm is simple, effective and easy to implement.

9

Authors: Kei Eguchi, Ichirou Oota, Shinya Terada, Hongbing Zhu

In signal processing circuits of a RDIF tag, the relaxation of restriction concerning operating voltage range enables us to develop various applications. In order to provide higher voltage to the signal processing circuit, two types of step-up AC-DC converters for RFID tags are proposed in this paper: the step-up converter and the step-up converter. To reduce ripple noise of output voltage, the proposed converters consist of 2 charge-pump type AC-DC converters with opposite polarities. Unlike conventional converters, the proposed converters can offer higher output voltages by realizing / step-up conversion. Furthermore, as for the step-up converter, the circuit size of the proposed converter is almost the same as that of the Cockcroft-Walton type AC-DC converter. The properties of the proposed converters are clarified by theoretical analyses. The theoretical formulas can derive the equivalent circuits, output voltages, and power efficiency. Furthermore, SPICE simulations and the experiments showed the validity of theoretical formulas and circuit design.