2014
2014
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Record 109 of
Title:Actively learning human gaze shifting paths for semantics-aware photo cropping
Author(s):Zhang, Luming(1); Gao, Yue(2); Ji, Rongrong(3); Xia, Yingjie(4); Dai, Qionghai(2); Li, Xuelong(5)Source: IEEE Transactions on Image Processing Volume: 23 Issue: 5 DOI: 10.1109/TIP.2014.2311658 Published: May 2014Abstract:Photo cropping is a widely used tool in printing industry, photography, and cinematography. Conventional cropping models suffer from the following three challenges. First, the deemphasized role of semantic contents that are many times more important than low-level features in photo aesthetics. Second, the absence of a sequential ordering in the existing models. In contrast, humans look at semantically important regions sequentially when viewing a photo. Third, the difficulty of leveraging inputs from multiple users. Experience from multiple users is particularly critical in cropping as photo assessment is quite a subjective task. To address these challenges, this paper proposes semantics-aware photo cropping, which crops a photo by simulating the process of humans sequentially perceiving semantically important regions of a photo. We first project the local features (graphlets in this paper) onto the semantic space, which is constructed based on the category information of the training photos. An efficient learning algorithm is then derived to sequentially select semantically representative graphlets of a photo, and the selecting process can be interpreted by a path, which simulates humans actively perceiving semantics in a photo. Furthermore, we learn a prior distribution of such active graphlet paths from training photos that are marked as aesthetically pleasing by multiple users. The learned priors enforce the corresponding active graphlet path of a test photo to be maximally similar to those from the training photos. Experimental results show that: 1) the active graphlet path accurately predicts human gaze shifting, and thus is more indicative for photo aesthetics than conventional saliency maps and 2) the cropped photos produced by our approach outperform its competitors in both qualitative and quantitative comparisons. ? 1992-2012 IEEE.Accession Number: 20141717618253 -
Record 110 of
Title:Spatio-temporal Laplacian pyramid coding for action recognition
Author(s):Shao, Ling(1,2); Zhen, Xiantong(2); Tao, Dacheng(3); Li, Xuelong(4)Source: IEEE Transactions on Cybernetics Volume: 44 Issue: 6 DOI: 10.1109/TCYB.2013.2273174 Published: June 2014Abstract:We present a novel descriptor, called spatio-temporal Laplacian pyramid coding (STLPC), for holistic representation of human actions. In contrast to sparse representations based on detected local interest points, STLPC regards a video sequence as a whole with spatio-temporal features directly extracted from it, which prevents the loss of information in sparse representations. Through decomposing each sequence into a set of band-pass-filtered components, the proposed pyramid model localizes features residing at different scales, and therefore is able to effectively encode the motion information of actions. To make features further invariant and resistant to distortions as well as noise, a bank of 3-D Gabor filters is applied to each level of the Laplacian pyramid, followed by max pooling within filter bands and over spatio-temporal neighborhoods. Since the convolving and pooling are performed spatio-temporally, the coding model can capture structural and motion information simultaneously and provide an informative representation of actions. The proposed method achieves superb recognition rates on the KTH, the multiview IXMAS, the challenging UCF Sports, and the newly released HMDB51 datasets. It outperforms state of the art methods showing its great potential on action recognition. ? 2013 IEEE.Accession Number: 20142217766270 -
Record 111 of
Title:Double optical path automatic positioning system of Shenguang III facility diagnostic instrument platform
Author(s):Wang, Wei(1); He, Junhua(1); Zhang, Min(1); Wei, Mingzhi(1); Yan, Yadong(1); Wang, Wei(1); Wang, Zhengzhou(1); Yang, Zhenghua(2); Yang, Pin(2)Source: Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams Volume: 26 Issue: 7 DOI: 10.11884/HPLPB201426.072003 Published: July 2014Abstract:The platform which is used to carry diagnostic instruments on Shenguang facility requires high positioning accuracy and working stability, and can aim at the target with reliability. A double optical path automatic adjusting and aiming system is designed, its position accuracy is 20 μm. It employs a double optical image system and a 3-DOF motion component. In this system, visual servo technology is used to realize the automatic aiming. Automatic positioning test indicates that pointing accuracy is 11 μm in x direction, 12 μm in y direction and radical positioning accuracy is 14 μm. Laser shot test with X-ray framing camera shows that the automatic aiming system can satisfy the projects requirement.Accession Number: 20142717903036 -
Record 112 of
Title:Phase control of light amplification in steady and transient processes in an inverted-Y atomic system with spontaneously generated coherence
Author(s):Tian, Si-Cong(1); Tong, Cun-Zhu(1); Wan, Ren-Gang(3); Ning, Yong-Qiang(1); Qin, Li(1); Liu, Yun(1); Wang, Li-Jun(1); Zhang, Hang(1); Wang, Zeng-Bin(4); Gao, Jin-Yue(2)Source: Chinese Physics B Volume: 23 Issue: 4 DOI: 10.1088/1674-1056/23/4/044205 Published: April 2014Abstract:We investigate the effects of spontaneously generated coherence (SGC) on both the steady and transient gain properties in a four-level inverted-Y-type atomic system in the presence of a weak probe, two strong coherent fields, and an incoherent pump. For the steady process, we find that the inversionless gain mainly origins from SGC. In particular, we can modulate the inversionless gain by changing the relative phase between the two fields. Moreover, the amplitude of the gain peak can be enhanced and the additional gain peak can appear by changing the detuning of the coupling field. As for the transient process, the transient gain properties can also be dramatically affected by the SGC. Compared to the case without SGC, the transient gain can be greatly enhanced with completely eliminated transient absorption by choosing the proper relative phase between the two fields. And the inverted-Y-type system with SGC can be simulated in both atomic and semiconductor quantum well systems avoiding the conditions of SGC. ? 2014 Chinese Physical Society and IOP Publishing Ltd.Accession Number: 20141917692118 -
Record 113 of
Title:Searching algorithm of auto-focusing based on MTF auxiliary focal judgment
Author(s):He, Zhen-Xin(1); Liu, Chun-Tong(1); Huang, Xian-Xiang(1); Wu, Guo-Jun(2); Zhang, Zhi-Li(1)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 43 Issue: 4 DOI: 10.3788/gzxb20144304.0411002 Published: April 2014Abstract:Traditional climbing search algorithm cannot usually focusing accurately due to the interference of evaluation function local extremum effected by measure environment. A searching algorithm of auto-focusing based on MTF auxiliary focal judgment was introduced to improve the climbing method. Definition evaluation function and MTF values of images were considered at the same time. And based on those results, search direction was judged. Slanted-edge method was improved to calculate the image MTF values accurately based on the auto-selection of slanted-edge area. At last, the principle and implementation of the improved algorithm was given. In the theodolite auto-fousing system, the system imaging effect was validated, and different initial position and circumstance were considered using the proposed searching algorithm. The experiment results of theodolite auto-focus system show that the improved climbing search algorithm can effectively eliminate the local extremum disturbance, and make the system searching focusing accurately and reliably.Accession Number: 20142117743306 -
Record 114 of
Title:An optimization model and genetic algorithm solution for automated celestial navigation of ships
Author(s):Li, Hui(1); Lu, Gang(2); Wang, Wei(3); Wang, An Guo(1)Source: Applied Mechanics and Materials Volume: 548-549 Issue: DOI: 10.4028/www.scientific.net/AMM.548-549.1277 Published: 2014Abstract:Inclination measurement errors have a significant effect on the positioning accuracy of an automated ship celestial navigation system using the existing theoretical models. To reduce such undesirable effect, we propose a nonlinear least-squares model based on global optimization and provide a genetic algorithm solution using proportional selection, arithmetical crossover, Gaussian mutation, and elitist strategy. The performance of the model and solution is demonstrated by an instance of simulation experiment. The results indicate that the global near-optimal solution of a ship's attitude and position can be obtained with accuracy of arc-second level, and the accuracy is better than that of the existing models by one to two orders of magnitude under the same measurement conditions. ? (2014) Trans Tech Publications, Switzerland.Accession Number: 20142417809231 -
Record 115 of
Title:Reconstruction of compressive spectral imaging system of a FISTA algorithm-based coded aperture
Author(s):Sun, Nian(1,2); Hu, Bingliang(1); Wang, Shuang(1); Sun, Lang(1); Wang, Zhengjie(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 43 Issue: 1 DOI: Published: January 2014Abstract:A compression and reconstruction solution based on coded aperture was proposed. In this system, the 3D spatial-spectral information about a scene of interest was coded by a random binary element pattern which was achieved by Digital Micro-Mirror Device (DMD), and the processing was snapshot. As a result the 3D information was encoded into a 2D representation. In decoding, a Fast Iterative Shrinkage-Thresholding Algorithm (FISTA) was proposed on the basis of the Two-Step Iterative Shrinkage-Thresholding (TwIST) algorithm. The method developed in this paper did not require more than one gradient evaluation at each iteration, but just an additional point was smartly chosen and easy to compute. The experiments show that the reconstruction performance is much better than TwIST and GPSR both in spatial dimension and spectral dimension.Accession Number: 20141017420274 -
Record 116 of
Title:Stray light analysis during non-collinear sum-frequency generation
Author(s):Yuan, Suochao(1); Gao, Limin(1); Li, Dongjian(1); Zhao, Juanning(1,2)Source: Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams Volume: 26 Issue: 1 DOI: 10.3788/HPLPB201426.011001 Published: January 2014Abstract:We analyze the stray light caused by surface scattering of the sum-frequency crystal in third-order correlation measurement and its influence on the contrast of the sum-frequency light. Besides, the expression of the stray light caused by surface scattering is given. When the surface roughness is 1% of the laser wavelength, the intensity of stray light reaches about 10-8. And the rougher the surface is, the more stray light it causes.Accession Number: 20140817350028 -
Record 117 of
Title:Monte carlo simulation of multifocal stochastic scanning system
Author(s):Liu, Lixin(1); Qian, Jia(2); Li, Yahui(1); Peng, Xiao(3); Yin, Jun(3)Source: Journal of Innovative Optical Health Sciences Volume: 7 Issue: 1 DOI: 10.1142/S1793545813500545 Published: 2014Abstract:Multifocal multiphoton microscopy (MMM) has greatly improved the utilization of excitation light and imaging speed due to parallel multiphoton excitation of the samples and simultaneous detection of the signals, which allows it to perform three-dimensional fast fluorescence imaging. Stochastic scanning can provide continuous, uniform and high-speed excitation of the sample, which makes it a suitable scanning scheme for MMM. In this paper, the graphical programming language-LabVIEW is used to achieve stochastic scanning of the two-dimensional galvo scanners by using white noise signals to control the x and y mirrors independently. Moreover, the stochastic scanning process is simulated by using Monte Carlo method. Our results show that MMM can avoid oversampling or subsampling in the scanning area and meet the requirements of uniform sampling by stochastically scanning the individual units of the N × N foci array. Therefore, continuous and uniform scanning in the whole field of view is implemented. ? 2014 The Authors.Accession Number: 20141417535901 -
Record 118 of
Title:Fast circle detection based on improved randomized Hough transform
Author(s):Shi, Dongchen(1); Zhang, Bo(2); Wang, Ning(3)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9285 Issue: DOI: 10.1117/12.2068644 Published: 2014Abstract:To solve the problem of a large amount of invalid sample and accumulations yielded by random sampling when randomized hough transform (RHT) is used to detect circles in complex images processing, an new improved arithmetic for circle detection is developed in this paper. It not only uses gradient direction information to determine whether the three sampling points should be accumulated or not, but also uses the regular hexagon window to narrow the searching range of pixels to improve the operating speed. The problem of invalid sampling and accumulations and multi-circle detection is well solved. The experiment results show that this algorithm has higher speed, smaller storage and better detection performance.Accession Number: 20150800545507 -
Record 119 of
Title:Talbot effect and noise reduction in image processing based on Gyrator transform
Author(s):Ma, Yuanhua(1,2); Hu, Bingliang(1); Li, Ran(1); Sun, Lang(1,2); Sun, Nian(1,2); Wang, Zhengjie(1,2)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 43 Issue: 2 DOI: Published: February 2014Abstract:Based on the principle of Gyrator transform, the self -imaging effect, i.e., the Talbot effect, was investigated firstly. The condition under which the Gyrator transform Talbot effect can occur was given, and the difference between the Talbot effect mentioned in this paper and the traditional Talbot effect was found the Talbot angle was not fixed, the distribution of the angles was not linear, and the fractional Gyrator transform Talbot effect could not obtain through fractionalizing the Talbot angle. Secondly, noise reduction in image processing based on Gyrator transform was also discussed in the paper. It was found that the Gyrator transform could not only reduce the hyperbolic noise efficiently, but also can reduce the-kind noise that brings hyperbolic information efficiently. At last, the shortcoming of the study and follow-up investigations were pointed out. The research in this paper can help people understand Gyrator transform deeply, also develop the self-imaging and noise reduction techniques.Accession Number: 20141317523556 -
Record 120 of
Title:Tracking of infrared small-target based on improved Mean-Shift algorithm
Author(s):Yang, Yifan(1,2); Tian, Yan(1); Yang, Fan(2,3); Huang, Biao(1,2)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 43 Issue: 7 DOI: Published: July 25, 2014Abstract:Small-target tracking in infrared imagery with a complex background is always an important task in object tracking fields. Small and manoeuvrable objects in complex clutter and highly noised background usually results in serious false alarm in target tarking for low contrast of infrared imagery. An improved Mean-Shift algorithm to handle the influnce of complex background during tracking the smalltarget in infrared imagery was proposed. This work proposed an adaptive nonlinear machine to help Mean-Shift algorithm to get stable histogram of the interesting areas. This machine expanded the imformation of object histogram refer to the mean value of tracking window, as well as reduced the noise part of tracking window refer to the standard deviation of it. At the same time, algorithm fused the histograms of gradient with histogram of gray-value to discribe the target. To validate the effection of the proposed algorithm, the last part conduct a series tracking experiments which choose highly noised and clutered videos as their candidates. The comparison of the tracking results between tradtional Mean-Shift algotithm and improved Mean-Shift algorithm shows that the proposed algorithm has a more accurate tracking effection. Further more the proposed algorithm highly reduced the wobbleing between small-target and tracking window. This indicates that the improved algorithm achieved more robustness.Accession Number: 20143600062406