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28 February 2018, Volume 39 Issue 1 Previous Issue    Next Issue

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Low-Light Image Enhancement Based on Iterative Multi-Scale Guided Filter Retinex ZHANG Jie1,2, ZHOU Pucheng1,2, ZHANG Qian1,2 2018, 39(1): 1-11.  DOI: 10.11996/JG.j.2095-302X.2018010001 Abstract ( 421 )   PDF (4682KB) ( 567 )   In order to improve the visual perception of low-light image, a kind of low-light image enhancement algorithm based on iterative multi-scale guided filter Retinex was proposed. Firstly, the low-light image was converted into YCbCr color space. Secondly, the illumination image of the Y channel was estimated with iterative multi-scale guided filter. By increasing the scale parameter and the smoothing parameter iteratively in exponential form, the edge was preserved and details of different contrasts was eliminate. And then, the reflected image was obtained by the estimated illumination image and the contrast correction procedure. Finally, the image was converted into RGB color space, and this is the final enhanced image. Experimental results show that our method can better obtain the illumination image so that the visual effect of the enhanced image can be improved obviously. Related Articles | Metrics

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Improved Distance Regularized Level Set Evolution Model by Enhancing Energy of Area Term ZHU Yunlong, WENG Guirong 2018, 39(1): 12-20.  DOI: 10.11996/JG.j.2095-302X.2018010012 Abstract ( 173 )   PDF (5691KB) ( 229 )   针对距离规则水平集演化(DRLSE)模型存在易陷入虚假边界、对噪声敏感、收敛 速度慢以及容易从弱边缘处泄露等不稳定问题，提出了面积项能量加强的水平集演化函数对水 平集方法进行改进。首先提出了一个自适应边缘指示函数，其根据图像信息来调整函数参数， 从而控制演化速度以及对噪声敏感度，使水平集演化更加快速稳定。同时结合区域生长方法， 将图像处理成一个二值矩阵，并据此矩阵增加一加强项，使得面积项能量得到加强，令水平集 函数随着距离目标远近而自动调整能量大小，降低计算成本，有效解决对噪声敏感、易陷入虚 假边界等问题。为验证模型的有效性，采用多张实图进行分割实验并与DRLSE 等模型进行对 比，实验结果表明，提出的模型能有效解决存在问题，有更高的计算效率和准确率。 Related Articles | Metrics

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A Hybrid Video Watermarking Algorithm Based on Artificial Bee Colony and Chaotic Mapping ZHU Shengfeng 2018, 39(1): 21-29.  DOI: 10.11996/JG.j.2095-302X.2018010021 Abstract ( 94 )   PDF (2387KB) ( 235 )   In order to solve the problem that the motion vector search is inefficient and the embedded watermark information is single, this paper integrates adaptive artificial bee colony and Powell local search to realize a moving object detection method based on independent component analysis. Adaptive search parameters are used to adjust neighborhood search scope dynamically, that makes artificial bee colony algorithm quickly converge to global optimal and achieve a more optimal solution. Then, all nectaries will be clustered by K-mean to be dependence of clustering result on the initial center, and then clustering results are divided into Powell local search, which accelerate the algorithm convergence speed. The motion component optimization problem is designed by using the independent component, and the optimal solution is solved by the improved method to extract the motion component in the video sequence. By using Logistic-sinusoidal mapping for chaotic encryption, the Arnold map is scrambled on the encrypted watermark image, and the final watermark information is embedded in B frame and P frame, and the real integrity of the video data is enhanced while improving the video data attack. The simulation results show that the hybrid watermark embedding algorithm has good performance in robustness and vulnerability. Related Articles | Metrics

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Distributed P2P Video on Demand Scheduling Based on Request Drop Neighborhood Overlay LI Lei1, LI Ling2 2018, 39(1): 30-35.  DOI: 10.11996/JG.j.2095-302X.2018010030 Abstract ( 88 )   PDF (2737KB) ( 240 )   In order to achieve peer-to-peer architectures for low cost video stream transmission and real-time playback requirements, this paper proposes a distributed P2P video on demand scheduling algorithm based on request drop neighborhood overlay. Firstly, this paper constructs technical index of P2P VOD (video on demand) based on the superposition technique, considers the three parameters optimization index of the input neighborhood nodes, the output neighborhood nodes and the media server load, and then constructs the overlay structure and distributed algorithm flow. Secondly, this paper uses the request descent strategy to improve the selection of the sending nodes and service nodes, which can solve the problem of broadband low utilization ratio and invalid video playback. Finally, experimental results based on the BitTorrent VOD system verify the effectiveness of the proposed algorithm. Related Articles | Metrics

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The Color Tread Image Segmentation Based on Improved Labeled Watershed MA Zengqiang, WANG Yongsheng, SONG Zibin, XIAO Meiling 2018, 39(1): 36-42.  DOI: 10.11996/JG.j.2095-302X.2018010036 Abstract ( 100 )   PDF (2335KB) ( 288 )   The tread image segmentation is the process of realizing the separation of tread area and background, which is the link between image preprocessing and tread image defect detection. Aimed at the problem of missing image information, low precision of regional contour segmentation and poor anti-interference ability, a method of color tread image segmentation based on improving watershed algorithm is presented in this paper. Firstly, the proportion of the incident component of the tread image with the reflective component and the RGB three color channel is adjusted by using the multi-scale retinal enhancement (MSRCR) with color restoration. Then the color image gradient graph is calculated directly. The color gradient image foreground and background mark is completed by improving RGB color component fusion operation and then the initial segmentation result is obtained by the watershed transformation. Finally, combined with the tread contour azimuth characteristic, image connected domain extraction segmentation algorithm is designed and the tread surface extraction is completed. The experimental results show that the method is good to divide the edges of the image, the color fidelity, the fog haze, the illumination disturbance ability, and obtain the ideal wheel tread segmentation results. Related Articles | Metrics

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Fisheye Lens Distortion Correction Method Based on Improved Spherical Perspective Projection WANG Xiangjun1,2, BAI Haoyue1,2, WU Fanlu1,2, YE Xiuling1 2018, 39(1): 43-49.  DOI: 10.11996/JG.j.2095-302X.2018010043 Abstract ( 203 )   PDF (4776KB) ( 730 )   The method of improving the constraints was proposed to enhance the efficiency of image rectification and reduce the large amount of calculation caused by using the traditional spherical perspective projection and intricacy of calibration. Firstly, identify the principal point of the fish-eye image and its radius by applying Hough transform circle detection to the characteristics of fish-eye image, and set the condition that a straight line comes out from the same arc through spherical perspective positive rejection as a constraint. The main view of fish-eye image could be rectified with the optimal projection sphere radius. Based on this method, a new two-dimension calibration method is put forward as sector mapping. Start from the trajectory projected from the edge of main view. Map the fish-eye image in polar coordinates and obtain the rectified surrounding view. Validate the effectiveness and feasibility of the method by two examples. Related Articles | Metrics

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Spherical Target Recognition Method Based on Mutual Exclusion of Spherical Centers LI Zikuan1, LIAO Wei2, LAN Qiuping1 2018, 39(1): 50-56.  DOI: 10.11996/JG.j.2095-302X.2018010050 Abstract ( 124 )   PDF (2363KB) ( 224 )   A new spherical target recognition method based on mutual exclusion of sphere centers is proposed to solve the automatically identification problems of unknown number and unknown radius targets in large-scale 3D point clouds. First, an effective spherical point response function is specially designed to remove most of aspheric points, and every remaining spherical point is mapped to a sphere center by taking advantage of its normal and curvatures. Then, a novel tree-like structure for describing distribution and local density change rules of these centers is constructed, through a series of pruning operation complying with the mutually exclusion relationships between different sphere centers, the tree is split into several sub-trees, and a sub-tree correspond to a possible sphere target. Finally, the real sphere is confirmed by the local density of the root node of sub-tree and the coverage rate of points on the sphere surface. The experimental results demonstrate that the proposed sphere recognition method based on the mutual exclusion of sphere centers can effectively identify and precisely loc ate various spherical targets in a large and cluttered scene. Even in the case of serious occlusion, such as the exposed surface is less than 6%, the sphere can also be robustly identified. Related Articles | Metrics

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Identification of Wheat Leaf Disease Based on Random Forest Method XIA Yongquan, WANG Bing, ZHI Jun, HUANG Haipeng, SUN Jingru 2018, 39(1): 57-62.  DOI: 10.11996/JG.j.2095-302X.2018010057 Abstract ( 122 )   PDF (638KB) ( 229 )   In order to improve the recognition accuracy of wheat leaf disease, the Gaussian mixture model combined with EM algorithm was used to extract the wheat leaves and obtain the bigger target, which made the segmentation accuracy higher than the direct segmentation disease area. And the roughness, the degree of orientation and the contrast were selected by combining the HSV main color histogram and the Tamura texture feature. The images of wheat healthy leaves, powdery mildew, leaf blight and leaf rust were identified by random forest method and recognition accuracy is up to 95%. Experiments show that this method is effective and superior to the support vector machine (SVM) method under the same conditions. Related Articles | Metrics

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The Extraction and Application of the Temperament Characteristics of Ladies Figurines in Tang Dynasty Based on Customer Satisfaction WANG Weiwei, ZHANG Yunyan, WANG Yi, WEI Ting 2018, 39(1): 63-67.  DOI: 10.11996/JG.j.2095-302X.2018010063 Abstract ( 130 )   PDF (3293KB) ( 239 )   The ladies figurines in Tang Dynasty embodies the temperament and charm of Tang culture. As their appearances are graceful and magnificent, so they have been vested with the characteristics of the time. We extracted the temperament characteristics based on customer’s satisfaction and parameterized them. Then they were applied to the ceramic design to promote the cultural connotation and the market competitiveness of the products, and it is conducive to the inheritance and innovation of traditional culture. Firstly, we selected the representative ladies figurines, and then through the perception analysis and the theory of demand transformation to get the semantics of the temperament characteristics which satisfies the expectation of the users. Secondly, we analyzed the geometric parameters of the temperament characteristics through the geometrical proportions method. Finally, we applied it to the design of cultural ceramic products, and the effectiveness of the methods and procedures have been verified. Related Articles | Metrics

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Research on the User Experience Evaluation of APP for the Elder Based on Grey AHP LI Yongfeng, SHI Weiwei, ZHU Liping 2018, 39(1): 68-74.  DOI: 10.11996/JG.j.2095-302X.2018010068 Abstract ( 258 )   PDF (2565KB) ( 549 )   To improve user experience (UX) level for the elder, this paper proposes an evaluation model of UX of APP for the elder based on grey analytic hierarchy process (AHP). Firstly, an evaluation system is built. Second, the elderly preference weights for evaluation indexes are investigated by AHP. Finally, the criteria of UX are integrated into grey relational grade by using grey relational analysis (GRA) to obtain optimal design. A mobile health application was chosen as a case study. The result indicates that the grey AHP-based evaluation model can be used to evaluate the UX level of APP for the elder effectively, and designers can achieve insights for decision making of design. Related Articles | Metrics

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Assembly System Construction and Its Key Techniques of Cable Harness under Virtual and Real Scene Fusion for Complex Mechatronic Products WANG Falin, GUO Yu, ZHA Shanshan 2018, 39(1): 75-84.  DOI: 10.11996/JG.j.2095-302X.2018010075 Abstract ( 154 )   PDF (2427KB) ( 319 )   In view of the problems of low efficiency, low accuracy, and assembling quality and reliability are difficult to guarantee which caused by the traditional cable simulation assembly experimental method based on physical prototype, this paper proposes an assembly method of cable harness under virtual and real scene fusion for complex mechatronic products. Firstly, we analyze the advantages of the augmented reality technology applied in the cable harness assembly, and construct the assembly system of cable harness under virtual and real scene fusion based on augmented reality. Secondly, we introduce the key technologies involved to the above assembly system, and elaborate the technologies of cable harness 3D registration, cable harness occlusion, cable harness illumination, and camera calibration and tracking. Finally, we introduce the research contents and give the assembly system running process of cable harness under virtual and real scene fusion based on augmented reality. Related Articles | Metrics

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Aided Learning System of Cross Platform Mobile Terminal Based on AR Technology ZHANG Haisen1, YANG Guanghui2, LIU Chaojian1, WANG Jilong1,LI Jixuan1, LANG Chen1 2018, 39(1): 85-90.  DOI: 10.11996/JG.j.2095-302X.2018010085 Abstract ( 310 )   PDF (4353KB) ( 438 )   In order to solve the existing limitations of traditional teaching methods such as textbook teaching and courseware teaching, combining Augmented Reality technology with existing teaching methods, using 3Ds max, Unity, NodeJS, MySQL and others software and technologies, by which a cross-platform mobile learning application “POU drawing–stereo classroom” is developed, which is based on Vuforia and EasyAR image recognition system. It is established in the teaching process of mechanical drawing and other courses. The starting point of this APP is multi-link, multi-disciplinary and multi-field. “POU drawing” is a mobile application, with the functions of identifying pictures automatically, displaying stereoscopic models instantly, touching control and multi-scene selection. Related Articles | Metrics

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An Optimization Algorithm for Rectangular Items Cutting Stock Problem Based on Two-Segment Patterns HU Shaohua, WU Shuyan, PAN Liwu 2018, 39(1): 91-96.  DOI: 10.11996/JG.j.2095-302X.2018010091 Abstract ( 137 )   PDF (359KB) ( 230 )   For on the rectangular items cutting stock problem, an optimization algorithm based on two-segment patterns is proposed. Firstly, a constrained packing algorithm is constructed to generate the two-segment patterns of rectangular items on the plate. Then, column generation algorithm is used to generate a virtual cutting plan according to the current remaining demand of rectangular items, several patterns are added into actual cutting plan according to the rule that no redundant rectangular item is generated, and the current remaining demand of rectangular items is updated. The above steps are repeated until the remaining demand of rectangular items is zero. Compared the proposed algorithm with two algorithms in the literature through benchmark instances, results of numerical experiments show that material utilization of the proposed algorithm is higher than two literature algorithms about 1.61% and 0.78%, respectively. Related Articles | Metrics

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Extension of the Cubic Triangular Bézier Surface of the Same Degree YAN Lanlan, WEN Rongsheng, RAO Zhiyong 2018, 39(1): 97-103.  DOI: 10.11996/JG.j.2095-302X.2018010097 Abstract ( 89 )   PDF (417KB) ( 172 )   In order to endow the cubic triangular Bézier surface the ability of shape adjustment, this paper constructs a set of cubic bivariate basis functions with a parameter and defines a new triangular surface determined by ten control points. The new surface has corner interpolation property. The tangent planes at the corner points are determined by the corner points and the two adjacent points which lie on the same edges. Changing the parameter value can adjust the shape of the surface. For convenient application, the G1 smooth join condition and the geometric iterative algorithm of the surface are given. The convergence as well as the relationship of the convergent rate and the parameter selection of the algorithm is analyzed. The legends show the correctness and validity of the method. Related Articles | Metrics

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Research and Application on Fast Construction of Welding Joints in Bus Frame Finite Element Model ZHAO Wentao1, CHEN Xiongwen2, ZHANG Chaohe3 2018, 39(1): 104-108.  DOI: 10.11996/JG.j.2095-302X.2018010104 Abstract ( 107 )   PDF (3263KB) ( 170 )   Truss structures are widely used in bridges, buildings and various frames, where a large number of similar solder joints exist, aiming at the problem of low efficiency and mutual difference on welding joints in the process of finite element modeling of bus frame, a method based on point cloud registration is proposed to rapidly construct the welding joints of profiles. Firstly, the structure and types of welding joints in the different parts of the bus frame are analyzed, on the basis of finite element mesh, for a large number of joints with similar topological structure and size, the mesh and node information are extracted, and then construct the equivalent joints and set of each part. Finally, principal component analysis and iterative closest point (ICP) algorithm are used to register the equivalent joint points and the corresponding cloud points on the frame, construct the welding joints by using point cloud fusion and the former problems are solved effectively. Related Articles | Metrics

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Research on Mass Customization Technology in Cloud Manufacturing Environment TONG Xiaowei1, LIU Yanbin2 2018, 39(1): 109-115.  DOI: 10.11996/JG.j.2095-302X.2018010109 Abstract ( 92 )   PDF (549KB) ( 195 )   Combined with the characteristics of cloud manufacturing and mass product customization, this paper proposes a model of mass product customization in cloud manufacturing environment and a matching demand transformation model. The demand transformation model covers the complete process of requirement decomposition, reorganization and redistribution. The requirements decomposition based on product tree and the manufacturing batch reorganization based on similarity clustering are described in detail. The demand redistribution non-linear programming model is provided, which can use the optimization method to achieve manufacturing demand optimization distribution. Finally, an example is given to illustrate the effectiveness and feasibility of the method, which demonstrates the effectiveness and feasibility of this method. Related Articles | Metrics

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Design of Arc Grinding System for Hardware Clamp Based on MCU STM32 WANG Chenggui1,2, YUE Dong1,2, GE Hui1,2, LI Genping1 2018, 39(1): 116-122.  DOI: 10.11996/JG.j.2095-302X.2018010116 Abstract ( 102 )   PDF (1255KB) ( 165 )   In this paper, a variety of widely used hardware clamp tools were taken as the processing object, and STM32F103ZET6 was adopted as the core processor of the hardware circuit to design a human-computer interaction system of automation grinding equipment. Meanwhile, a completed mechanical grinding platform according to the system was designed as well and grinding automation equipment was integrated based on embedded hardware clamp tools. The system contains a dynamic adjustment of the arc grinding algorithm, which can adjust the input parameters dynamically according to the different arc sizes and shapes. This system will automatically calculate the interpolation of the movement of the path to complete the automated grinding. Finally, the debugging result shows that the system is running smoothly and the interpolation is accurate. Related Articles | Metrics

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Simplification Method of Information Modeling in the Building Project Operation and Maintenance Stage GUO Siyi, CHEN Yongfeng 2018, 39(1): 123-128.  DOI: 10.11996/JG.j.2095-302X.2018010123 Abstract ( 189 )   PDF (728KB) ( 396 )   BIM technology penetration rate is much lower than the promotion efforts in our country, one of the main reasons is BIM model with large amounts of data are too demanding on computers. To solve this problem and make BIM model increasingly universal. By using the Revit API to achieve quadratic development and using the grid model simplification algorithm, the two aspect of the BIM models are quantized separately. Reduce the hardware requirements and make the BIM lifecycle model more universal. This has a great significance for BIM development in China. The result shows that this method can achieve the simplification method of BIM without affecting the use on the operation and maintenance stage. Related Articles | Metrics

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Analysis of Low-Wind-Pressure Conductor Based on Finite Element ZHOU Chao1, CHEN Zuo1, LI Li2, LIU Yanping1, SONG Yuwang1 2018, 39(1): 129-135.  DOI: 10.11996/JG.j.2095-302X.2018010129 Abstract ( 108 )   PDF (1917KB) ( 233 )   In order to reduce the wind pressure on the surface of the conductor, scholars at home and abroad have put forward a series of low-wind-pressure conductors with different section shapes and validated their working mechanism. However, there are few reports about the structural stability of the low-wind-pressure conductor and the problem of strand jumping. Therefore, the finite element model is established for aluminum conductor steel reinforced commonly used and low-wind-pressure conductor by ANSYS software. Based on criterion of strand jumping occurred on line, the displacement cloud and structural stability of the wire under different working conditions are analyzed. At the same time, the relationship between the number of outermost wire strands and the stability of conductor structure is discussed. The results show that the more the conductor number of the outer ring, the more stable the wire structure. Related Articles | Metrics

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Interpretation of Descriptive Geometry HE Yuanjun 2018, 39(1): 136-147.  DOI: 10.11996/JG.j.2095-302X.2018010136 Abstract ( 149 )   PDF (729KB) ( 368 )   From the aspect of geometry, this paper gives new understandings on descriptive geometry. Combined with the demand for computerization, the theory system of descriptive geometry is clarified. On this basis, some expressions in some textbooks of descriptive geometry are first reframed. Then the essences of theories on projection, 2D/3D corresponding, drawing by ruler and compass, as well as isometric drawing, shadow and perspective are revealed. Problems related to computerize these theories are further discussed. In the end, some assumptions are proposed to the development of descriptive geometry both in theory and in application. Related Articles | Metrics

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The Achievements and Scientific Value of Mo-Tse in the Theory of Graphics and Geometry LIU Keming 2018, 39(1): 148-158.  DOI: 10.11996/JG.j.2095-302X.2018010148 Abstract ( 161 )   PDF (3592KB) ( 272 )   “Mo-tse” is the first systematic exposition of the theory of knowledge and science and technology in the history of science and technology in ancient China. “Mo-tse” records show that: drawings, drawings and words and figures play an irreplaceable role on the human social progress and the development of science and technology. However, it is still a subject that needs to be deeply and systematically to discuss “Mo-tse”, especially for the definition and status of the graph and descriptive geometry theory. Through the investigation of “Mo-tse” about basic concept and theories on graphics, this article summarized graphics mapping in practice and theories, and reflect the scientific exploration spirit. Related Articles | Metrics

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Teaching Software Development of Cold Stamping Die Design Course HU Bifu, WANG Xuerui, LI Weidong 2018, 39(1): 159-163.  DOI: 10.11996/JG.j.2095-302X.2018010159 Abstract ( 99 )   PDF (948KB) ( 241 )   Combined with the practical teaching of the mold design course in the major of Aircraft Manufacturing Engineering, the parts characteristics and cold stamping die design process are summarized and a method of mold design flow is put forward. Then, a teaching software for cold stamping die design is developed based on CATIA platform to facilitate teachers in the teaching process. Based on this software, teachers can quickly show more sets of different parameters of the mold design process. This achievement could enhance the students’ knowledge and improve teaching effectiveness. Related Articles | Metrics

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The Promotion of Graphics Competition to Reform and Innovation in Graphics Teaching CHEN Haibo1, TAO Ye1, WU Muchun1, HUANG Wenyong2, ZHANG Zhichao3 2018, 39(1): 164-168.  DOI: 10.11996/JG.j.2095-302X.2018010164 Abstract ( 124 )   PDF (318KB) ( 261 )   Reform and innovation in graphics teaching based on “Higher Education Cup” graphics competition is discussed from five aspects of curriculum system, teaching resources, teaching mode, laboratory construction and teacher’s teaching and research ability in this paper by using the case study of South China Agricultural University. In the aspect of the curriculum system, the curriculum system of engineering graphics was constructed which combined basic courses and comprehensive improvement courses. The “Internet +” teaching resources was builded and optimized in the teaching resources. The progressive stage project–based teaching was tried in the teaching mode. The hardware modernization was strengthened and an open subject competition laboratory was constructed. The effect of competition on the teacher’s teaching, scientific research and teaching reform is also expounded. According to “the undergraduate teaching quality and teaching reform project”, colleges should take “Higher Education Cup” graphics competition as an opportunity, combining with classroom learning and extracurricular practice to actively explore the reform of graphics teaching in favor of the cultivation of innovative talents. Related Articles | Metrics

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Reconstruction of the Teaching Model of Computer Aided Product Rendering Based on SPOC PAN Xiaodong, LU Yizhou 2018, 39(1): 169-174.  DOI: 10.11996/JG.j.2095-302X.2018010169 Abstract ( 75 )   PDF (1026KB) ( 314 )   In view of the limitations and problems of the traditional teaching of computer aided product rendering, the paper combines with the specific analysis of its causes, puts forward the blended teaching with internet technology is a feasible reform direction. And the small private onlin course (SPOC) model is used to reconstruct the original course content and teaching form. Through the teaching practice, an important part of SPOC curriculum implementation and effect of content construction, teaching evaluation is analyzed and studied, and through the data analysis of test results, the effectiveness of the SPOC model to improve the teaching quality of this course has been verified. It has made beneficial exploration and attempt for the teaching reform of computer aided design. Related Articles | Metrics

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Application of Augmented Reality Technology in Engineering Graphics Education YU Yong, ZHAO Gang, LI Yachu 2018, 39(1): 175-178.  DOI: 10.11996/JG.j.2095-302X.2018010175 Abstract ( 136 )   PDF (3406KB) ( 442 )   Teaching and research are two categories with strong interaction. Scientific research supplies materials for teaching, while teaching provides innovation inspiration for scientific research in turn. This paper explores how to enrich the amount of information in class and stimulate students’ interest in learning engineering graphics through interaction between teaching and research. It proves that not only the teaching becomes vivid and full of lectures, but the students’ knowledge is broadened and their interests in scientific research are stimulated effectively, if we add some scientific research cases to the classroom, such as virtual model representation by Augmented Reality technology. Related Articles | Metrics