摘要：
Purpose - The purpose of this paper is to develop a compressive sensing (CS) algorithm for noisy solder joint imagery compression and recovery. A fast gradient-based compressive sensing (FGbCS) approach is proposed based on the convex optimization. The proposed algorithm is able to improve performance in terms of peak signal noise ratio (PSNR) and computational cost. Design/methodology/approach - Unlike traditional CS methods, the authors first transformed a noise solder joint image to a sparse signal by a discrete cosine transform (DCT), so that the reconstruction of noisy solder joint imagery is changed to a convex optimization problem. Then, a so-called gradient-based method is utilized for solving the problem. To improve the method efficiency, the authors assume the problem to be convex with the Lipschitz gradient through the replacement of an iteration parameter by the Lipschitz constant. Moreover, a FGbCS algorithm is proposed to recover the noisy solder joint imagery under different parameters. Findings - Experiments reveal that the proposed algorithm can achieve better results on PNSR with fewer computational costs than classical algorithms like Orthogonal Matching Pursuit (OMP), Greedy Basis Pursuit (GBP), Subspace Pursuit (SP), Compressive Sampling Matching Pursuit (CoSaMP) and Iterative Re-weighted Least Squares (IRLS). Convergence of the proposed algorithm is with a faster rate O(kk) instead of O(1/k). Practical implications - This paper provides a novel methodology for the CS of noisy solder joint imagery, and the proposed algorithm can also be used in other imagery compression and recovery. Originality/value - According to the CS theory, a sparse or compressible signal can be represented by a fewer number of bases than those required by the Nyquist theorem. The new development might provide some fundamental guidelines for noisy imagery compression and recovering.
会议名称：
2015 16th International Conference on Electronic Packaging Technology (ICEPT)
关键词：
Principal Component analysis;Surface Mount Technology;Character recognition
摘要：
In this paper, we present an approach to recognizing characters in surface mount technology (SMT) product. Firstly, we capture the SMT characters image by a camera. Some feature information which can represent the SMT product character images is extracted. Secondly, by processing and analyzing the feature information, Principal Component analysis is used in characters recognition. Lastly, a SMT characters recognition system based on VC++ is developed. The experiment has shown that the system has some advantages in acquisition speed, readability and portability, and practical.
关键词：
CFD;Flow field distribution;Insertion flowmeter
摘要：
The study is to employ the analysis method of CFD simulation, when putting the insertion flow sensor in large-diameter pipe, to analyse the characteristics of flow field distribution of the insertion flow sensor in detail. It reveals the flow field distribution at the position of average flowrate and the vortex shedding around insertion flow sensor, which provides an important basis for design of the insertion flow sensor with high performance.
期刊：
Applied Mechanics and Materials,2012年157-158:1008-1011 ISSN：1660-9336
通讯作者：
Zhao, Huihuang
作者机构：
[Chen, Jianzhen; Zhao, Huihuang; Sun, Yaqi] Hengyang Normal Univ, Dept Comp, Hengyang 421008, Hunan, Peoples R China.;[Zhao, Huihuang; Wang, Yaonan] Hunan Univ, Dept Control Sci & Engn, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Zhao, Huihuang] H;Hengyang Normal Univ, Dept Comp, Hengyang 421008, Hunan, Peoples R China.
会议名称：
2011 International Conference on Mechatronics and Applied Mechanics(2011年机电一体化与应用力学国际会议 ICMAM 2011)
会议时间：
2011-12-27
会议地点：
香港
会议主办单位：
[Zhao, Huihuang;Sun, Yaqi;Chen, Jianzhen] Hengyang Normal Univ, Dept Comp, Hengyang 421008, Hunan, Peoples R China.^[Zhao, Huihuang;Wang, Yaonan] Hunan Univ, Dept Control Sci & Engn, Changsha 410082, Hunan, Peoples R China.
会议论文集名称：
2011 International Conference on Mechatronics and Applied Mechanics(2011年机电一体化与应用力学国际会议 ICMAM 2011)论文集
关键词：
Human face;Three-dimensional reconstruction;Shape from shading;Wavelet packet transform
摘要：
Human face three-dimensional (3D) reconstruction is a challenging problem. In this paper, we propose a human face fast- 3D- reconstruction method based on image processing with a single image. Shape from shading (SFS) is chosen to reconstruct the human face. First, SFS theory is introduced. It has the advantage of fast 3D reconstruction and only need a single image. Secondly, because the noise will affect the 3D reconstruction result greatly, wavelet transform and wavelet packet transform are introduced and used in image denoising respectively. The experiment has shown that the method based on wavelet transform produces the best denoising result than wavelet packet transform. At last, a human face 3D reconstruction algorithm based on a single image is proposed. The experimental results show that a human face 3D model can be reconstructed in fast by proposed algorithm.
