2016
2016
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Record 289 of
Title:Synthesized computational aesthetic evaluation of photos
Author(s):Wang, Weining(1); Cai, Dong(1); Wang, Li(1); Huang, Qinghua(1); Xu, Xiangmin(1); Li, Xuelong(2)Source: Neurocomputing Volume: 172 Issue: DOI: 10.1016/j.neucom.2014.12.106 Published: January 8, 2016Abstract:Assessing aesthetic appeal of images is a highly subjective task which has attracted a lot of interests recently. It is an interdisciplinary subject related to art, psychology, and computer vision. In this paper, we systematically study prior researches of feature extraction in this area, and category them into four groups, low level, rule based, information theory, and visual attention. In each group, the effectiveness and limitations of existing features are examined. Based on the analysis, we propose a comprehensive feature set, which include 16 novel features and 70 well proved features. With this feature set, we build the system under machine learning scheme consisting of an SVM based classifier to estimate if an image is high aesthetic or low aesthetic. The experiments are conducted on public datasets show that our comprehensive feature set outperforms conventional models that concentrate mainly on certain types of features. The combination of our features produces a promising classification accuracy of 82.4% and a good performance comparable to aesthetic rating of human. Finally, we implemented the proposed evaluation system on mobile devices. It can provide real-time feedback to help users capture appealing photos. ? 2015 Elsevier B.V.Accession Number: 20152400935648 -
Record 290 of
Title:Mirrors fabricated with slightly oxidized C/C composites
Author(s):Wang, Yongjie(1); Xu, Liang(1); Ding, Jiaoteng(1); Xie, Yongjie(1); Ma, Zhen(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9683 Issue: DOI: 10.1117/12.2243745 Published: 2016Abstract:Up to now, traditional materials, such as glass, metal and SiC ceramic, gradually begin to be unsatisfied development of the future mirrors. Designable carbon fiber reinforced composites became optimized material for large aperture lightweight mirrors. Carbon/carbon composites exhibit low thermal expansion and no moisture-absorption expansion problem, therefore, they get particular attention in the space reflector field. Ni was always employed as optical layer in the mirror, however, the coating behaved poor bond with substrate and often peeled off during optical processing. In order to solve this problem, slight oxidation was carried on the C/C composites before Ni plated. The Ni coating exhibited stronger coherence and better finish performance. Finally, a 100mm diameter plane mirror was successful fabricated. ? 2016 SPIE.Accession Number: 20164903096465 -
Record 291 of
Title:A novel method to real-time offset correction for frame transfer CCD
Author(s):Chen, Zhi(1); Wen, Yan(1); Yao, Dalei(1); Jiang, Baotan(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9686 Issue: DOI: 10.1117/12.2242264 Published: 2016Abstract:The traditional CCD offset correction processing method is to obtain normal exposure image and dark field image respectively. In the later image processing, use normal exposure image minus the dark field image. Although traditional method can offset correction, but cannot to realize real-time offset correction. Because the traditional method is to obtain offset correction after acquire normal exposure image and dark field image, while the normal exposure image and dark field image is not acquired at the same time. This method would reduce the offset correction precision. A novel method to real-time offset correction for frame transfer CCD is proposed in this paper. The method is based on the improvement of the traditional frame transfer CCD driving timing and CCD signal processing sequence. The traditional frame transfer CCD driving timing is exposure, frame transfer and read CCD level shift register. An offset correction line is added before read CCD data storage area to acquire the offset variation of the each frame image. Take it as a normal image data. In CCD signal processing algorithm to offset calculation and correction. This novel method can correct the offset of each frame image each pixel data real time. In this way the effect on the images from the variation of the offset caused by factors such as the working temperature and the aging of electronic devices in CCD signal processing circuit of CCD camera is restrained. ? 2016 SPIE.Accession Number: 20164903096158 -
Record 292 of
Title:High-Order Energies for Stereo Segmentation
Author(s):Peng, Jianteng(1); Shen, Jianbing(1); Li, Xuelong(2)Source: IEEE Transactions on Cybernetics Volume: 46 Issue: 7 DOI: 10.1109/TCYB.2015.2453091 Published: July 2016Abstract:In this paper, we propose a novel segmentation approach for stereo images using the high-order energy optimization, which utilizes the disparity maps and statistical information of stereo images to enrich the high-order potential functions. To the best of our knowledge, our approach is the first one to formulate the problem of stereo segmentation as a high-order energy optimization problem, which simultaneously segments the foreground objects in left and right images using the proposed high-order potential function. A new method for designing the penalty function in our high-order term is proposed by the corresponding pixels and their neighboring pixels between left and right images. The relationships of stereo correspondence by disparity maps are further employed to enhance the connections between the left and right stereo images. Experimental results demonstrate that the proposed approach can effectively improve the performance of two kinds of stereo segmentation, including the automatic saliency-aware stereocut and the interactive stereo segmentation with user scribbles. ? 2015 IEEE.Accession Number: 20153001069683 -
Record 293 of
Title:Bandwidth-tunable dissipative soliton and noise-like pulse in a normal dispersion fiber laser with a dual-scale saturable absorber
Author(s):Cui, Yudong(1,2,3)Source: Journal of Optics (United Kingdom) Volume: 18 Issue: 10 DOI: 10.1088/2040-8978/18/10/105503 Published: October 2016Abstract:A bandwidth-tunable dissipative soliton (DS) and noise-like pulse are demonstrated in an all-fiber normal dispersion fiber laser by employing a novel spectral filtering scheme. The mode locker is fabricated with a mixture composite that combines the merits of graphene and carbon nanotubes. At a pump power of 39 mW, a DS with knife edges is generated at 1565 nm. One of the steep edges is induced by gain spectral filtering and another is cut by a chirped fiber Bragg grating (CFBG). With higher pump power, the noise-like pulse operation displays an asymmetric spectral profile, confirming the novel combined spectral filtering. When the CFBG is stretched mechanically, the bandwidth of the DS and noise-like pulse can be tuned. The bandwidth-tunable mode-locked fiber laser has numerous potential applications, such as pulse shaping, as an amplifier and in optical nonlinear investigations. ? 2016 IOP Publishing Ltd.Accession Number: 20164102882735 -
Record 294 of
Title:Development and alignment for SiC mirror subsystem of a space-borne telescope
Author(s):Feng, Liangjie(1); Wang, Wei(1); Ren, Guorui(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10154 Issue: DOI: 10.1117/12.2247416 Published: 2016Abstract:A Φ600mm SiC primary mirror subsystem of a space-borne Ritchey-Chretien telescope was designed. The open-back primary mirror was made of pressure-less sintering silicon carbide (SiC), light-weighted at a ratio of approximately 70%. Minimizing the optical surface astigmatism was critical for the mirror, the astigmatism is caused mainly by gravity effects, temperature variation and the bonding process. Three invar flexure bipods were fixed on the baseplate of the telescope at first, and the posture of the primary mirror was adjusted precisely for 0.2mm gap to the bipods. 3M 2216 B/A grey adhesive was then injected into the gap between the mirror and bipod flexure, the curing process was last 72 hours in the room temperature. So the mirror was affected only by curing stress of the adhesive during the assembly process. Structural strength and dynamic stiffness of the mirror subsystem in the thermal-structural coupling state were analyzed with finite element method. Analyzed results show that the optical surface distortion is less than 1/50 at 632.8nm RMS with three points support and less than 1/200λ RMS with 2°C temperature variation because of the flexure support and compatible support and mirror material, The optical performance test with interferometer show that the optical surface distortion caused by the curing stress of the adhesive is less than 1/50λRMS, the overall optical surface of the primary mirror is less than 1/30λ rms, which met the critical requirements for the primary mirror of the telescope. ? 2016 SPIE.Accession Number: 20170503309988 -
Record 295 of
Title:Highly efficient spectrally encoded imaging using a 45° tilted fiber grating
Author(s):Wang, Guoqing(1); Wang, Chao(1); Yan, Zhijun(2,3); Zhang, Lin(2)Source: Optics Letters Volume: 41 Issue: 11 DOI: 10.1364/OL.41.002398 Published: June 1, 2016Abstract:A novel highly efficient, fiber-compatible spectrally encoded imaging (SEI) system using a 45° tilted fiber grating (TFG) is proposed and experimentally demonstrated for the first time, to the best of our knowledge. The TFG serves as an in-fiber lateral diffraction element, eliminating the need for bulky and lossy free-space diffraction gratings in conventional SEI systems. Under proper polarization control, due to the strong tilted reflection, the 45° TFG offers a diffraction efficiency as high as 93.5%. Our new design significantly reduces the volume of the SEI system and improves energy efficiency and system stability. As a proof-ofprinciple experiment, spectrally encoded imaging of a customer-designed sample (9.6 mm x 3.0 mm) using the TFG-based system is demonstrated. The lateral resolution of the SEI system is measured to be 42 μm in our experiment. ? 2016 Optical Society of America.Accession Number: 20162502528548 -
Record 296 of
Title:Atom decomposition with adaptive basis selection strategy for matrix completion
Author(s):Hu, Yao(1); Zhao, Chen(1); Cai, Deng(1); He, Xiaofei(1); Li, Xuelong(2)Source: ACM Transactions on Multimedia Computing, Communications and Applications Volume: 12 Issue: 3 DOI: 10.1145/2903716 Published: June 2016Abstract:Estimating missing entries in matrices has attracted much attention due to its wide range of applications like image inpainting and video denoising, which are usually considered as low-rank matrix completion problems theoretically. It is common to consider nuclear norm as a surrogate of the rank operator since it is the tightest convex lower bound of the rank operator under certain conditions. However, most approaches based on nuclear norm minimization involve a number of singular value decomposition (SVD) operations. Given a matrix X ∈ Rmxn, the time complexity of the SVD operation is O(mn2), which brings prohibitive computational burden on large-scale matrices, limiting the further usage of these methods in real applications. Motivated by this observation, a series of atom-decomposition-based matrix completion methods have been studied. The key to these methods is to reconstruct the target matrix by pursuit methods in a greedy way, which only involves the computation of the top SVD and has great advantages in efficiency compared with the SVD-based matrix completion methods. However, due to gradually serious accumulation errors, atom-decomposition-based methods usually result in unsatisfactory reconstruction accuracy. In this article, we propose a new efficient and scalable atom decomposition algorithm for matrix completion called Adaptive Basis Selection Strategy (ABSS). Different from traditional greedy atom decomposition methods, a two-phase strategy is conducted to generate the basis separately via different strategies according to their different nature. At first, we globally prune the basis space to eliminate the unimportant basis as much as possible and locate the probable subspace containing the most informative basis. Then, another group of basis spaces are learned to improve the recovery accuracy based on local information. In this way, our proposed algorithm breaks through the accuracy bottleneck of traditional atom-decomposition-based matrix completion methods; meanwhile, it reserves the innate efficiency advantages over SVD-based matrix completion methods. We empirically evaluate the proposed algorithm ABSS on real visual image data and large-scale recommendation datasets. Results have shown that ABSS has much better reconstruction accuracy with comparable cost to atom-decomposition-based methods. At the same time, it outperforms the state-of-the-art SVD-based matrix completion algorithms by similar or better reconstruction accuracy with enormous advantages on efficiency. ? 2016 ACM.Accession Number: 20162702559516 -
Record 297 of
Title:Efficient and Robust Learning for Sustainable and Reacquisition-Enabled Hand Tracking
Author(s):Abdul Aziz, Muhammad Ali(1); Niu, Jianwei(1); Zhao, Xiaoke(1); Li, Xuelong(2)Source: IEEE Transactions on Cybernetics Volume: 46 Issue: 4 DOI: 10.1109/TCYB.2015.2418275 Published: April 2016Abstract:The use of machine learning approaches for long-term hand tracking poses some major challenges such as attaining robustness to inconsistencies in lighting, scale and object appearances, background clutter, and total object occlusion/disappearance. To address these issues in this paper, we present a robust machine learning approach based on enhanced particle filter trackers. The inherent drawbacks associated with the particle filter approach, i.e., sample degeneration and sample impoverishment, are minimized by infusing the particle filter with the mean shift approach. Moreover, to instill our tracker with reacquisition ability, we propose a rotation invariant and efficient detection framework named beta histograms of oriented gradients. Our robust appearance model operates on the red, green, blue color histogram and our newly proposed rotation invariant noise compensated local binary patterns descriptor, which is a noise compensated, rotation invariant version of the local binary patterns descriptor. Through our experiments, we demonstrate that our proposed hand tracker performs favorably against state-of-the-art algorithms on numerous challenging video sequences of hand postures, and overcomes the largely unsolved problem of redetecting hands after they vanish and reappear into the frame. ? 2015 IEEE.Accession Number: 20151700776962 -
Record 298 of
Title:Numerical simulation and analysis of wavefront reconstruction in radial shearing interference
Author(s):Wang, Yufei(1); Da, Zhengshang(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 45 Issue: 3 DOI: 10.3788/IRLA201645.0317001 Published: March 25, 2016Abstract:In order to acquire the original wavefront information in radial shearing interferometry, wavefront reconstruction is necessary, the iterative algorism for wavefront reconstruction was deduced in this paper, based on which an numerical simulation using Matlab with different iteration number and shearing ratio was conducted. The simulation comes to the following conclusion: Properly selection of the shearing ratio can simplify the computational complexity. Compared with the small distortion wavefront reconstruction, more but appropriate iteration number in large distortion wavefront reconstruction is needed. Preferred shearing ratios for different measured wavefront PV values are summarized as follows: a. if WPV>10λ, beta>0.7; b. if 6λ ? 2016, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved.Accession Number: 20161802339242 -
Record 299 of
Title:Large-Scale Aerial Image Categorization Using a Multitask Topological Codebook
Author(s):Zhang, Luming(1); Wang, Meng(1); Hong, Richang(1); Yin, Bao-Cai(2); Li, Xuelong(3)Source: IEEE Transactions on Cybernetics Volume: 46 Issue: 2 DOI: 10.1109/TCYB.2015.2408592 Published: February 2016Abstract:Fast and accurately categorizing the millions of aerial images on Google Maps is a useful technique in pattern recognition. Existing methods cannot handle this task successfully due to two reasons: 1) the aerial images' topologies are the key feature to distinguish their categories, but they cannot be effectively encoded by a conventional visual codebook and 2) it is challenging to build a realtime image categorization system, as some geo-Aware Apps update over 20 aerial images per second. To solve these problems, we propose an efficient aerial image categorization algorithm. It focuses on learning a discriminative topological codebook of aerial images under a multitask learning framework. The pipeline can be summarized as follows. We first construct a region adjacency graph (RAG) that describes the topology of each aerial image. Naturally, aerial image categorization can be formulated as RAG-To-RAG matching. According to graph theory, RAG-To-RAG matching is conducted by enumeratively comparing all their respective graphlets (i.e., small subgraphs). To alleviate the high time consumption, we propose to learn a codebook containing topologies jointly discriminative to multiple categories. The learned topological codebook guides the extraction of the discriminative graphlets. Finally, these graphlets are integrated into an AdaBoost model for predicting aerial image categories. Experimental results show that our approach is competitive to several existing recognition models. Furthermore, over 24 aerial images are processed per second, demonstrating that our approach is ready for real-world applications. ? 2013 IEEE.Accession Number: 20151200667619 -
Record 300 of
Title:Compressed sensing sparse reconstruction for coherent field imaging
Author(s):Cao, Bei(1); Luo, Xiu-Juan(1); Zhang, Yu(1); Liu, Hui(1); Chen, Ming-Lai(1)Source: Chinese Physics B Volume: 25 Issue: 4 DOI: 10.1088/1674-1056/25/4/040701 Published: April 1, 2016Abstract:Return signal processing and reconstruction plays a pivotal role in coherent field imaging, having a significant influence on the quality of the reconstructed image. To reduce the required samples and accelerate the sampling process, we propose a genuine sparse reconstruction scheme based on compressed sensing theory. By analyzing the sparsity of the received signal in the Fourier spectrum domain, we accomplish an effective random projection and then reconstruct the return signal from as little as 10% of traditional samples, finally acquiring the target image precisely. The results of the numerical simulations and practical experiments verify the correctness of the proposed method, providing an efficient processing approach for imaging fast-moving targets in the future. ? 2016 Chinese Physical Society and IOP Publishing Ltd.Accession Number: 20161702279006