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Topological charge independent frequency conversion of twisted light [article]

Yan Li, Zhi-Yuan Zhou, Shi-Long Liu, Shi-Kai Liu, Chen Yang, Zhao-Huai Xu, Yin-Hai Li, Guang-Can Guo, Bao-Sen Shi
2018 arXiv   pre-print
Here we conceive and develop a method to eliminate the dependence of conversion efficiency on topological charges in second harmonic generation (SHG) process by utilizing a special designed image technique  ...  For light-matter interacting with twisted light like quantum memory and nonlinear frequency conversion, efficiencies in these processes are usually decreasing exponentially with topological charges, which  ...  Fig. 3 . 3 Images of the SHG beam and the fringes transformed with a pair of cylindrical lenses for pump beam with topological charges of 1, 2, 3.  ... 
arXiv:1810.07846v1 fatcat:yfzrcidcwrhu3m2thupdxm3rjy

A Coarse-to-Fine Registration Method Based on Geometric Constraints and Parallel Architecture

Zetao Jiang, Chuan Guo, Yang Yang
2015 Journal of Software  
First, in order to provide geometric constraints for block and fine registration, we use SIFT algorithm parallelly extract feature points to calculate initial transform matrix.  ...  Aiming at solving lengthy time-consuming registration and mismatch problems caused by images which have feature simliarity of local region in the traditional SIFT (Scale Invariant Feature Transform) registration  ...  But this is difficult for registering distorted images and the efficiency of this method is not high.  ... 
doi:10.17706/jsw.10.5.551-565 fatcat:i5jfoxk5yzbblktwpdxwp7bu7q

A statistical reduced-reference method for color image quality assessment [article]

Mounir Omari, Mohammed El Hassouni, Abdelkaher Ait Abdelouahad, Hocine Cherifi
2014 arXiv   pre-print
In this paper, we propose a natural scene statistic (NSS) method, which efficiently uses this information.  ...  We propose and analyze the multivariate generalized Gaussian distribution (MGGD) to model the underlying statistics.  ...  process that transforms the image into different spatial frequency as well as orientation selective sub-bands.  ... 
arXiv:1411.7655v1 fatcat:rt6pevo7wzhwxcbocv56na744i

An Optimal Reduced Representation of a MoG with Applicatios to Medical Image Database Classification

Jacob Goldberger, Hayit Greenspan, Jeremie Dreyfuss
2007 2007 IEEE Conference on Computer Vision and Pattern Recognition  
We propose a novel algorithm for learning a reduced representation of a MoG, that is based on the Unscented-Transform.  ...  This work focuses on a general framework for image categorization, classification and retrieval that may be appropriate for medical image archives.  ...  The distance between each image MoG and each category model is computed and the images are classified to the category for which this distance is minimal.  ... 
doi:10.1109/cvpr.2007.383334 dblp:conf/cvpr/GoldbergerGD07 fatcat:jep43vpl6jdkbop6z5mnyewp5m

Multi Wavelet for Image Retrival Based On Using Texture and Color Querys

K. Joseph Bhushanam
2012 IOSR Journal of Computer Engineering  
Efficient, texture representation is important, in search and retrieval of similar texture patterns from a large image database.  ...  Firstly, we calculate the multi wavelet of all images in database.secondly, to calculate the energy and then distance between query and database images.  ...  The Gabor transform of a signal x(t) is defined by this formula: (1) The Gaussian function has infinite range and it is impractical for implementation.  ... 
doi:10.9790/0661-0661013 fatcat:kl6zhfoukfetjjb77sglybect4

Face Recognition Based on Improved SIFT Algorithm

EHSAN SADEGHIPOUR, NASROLLAH SAHRAGARD
2016 International Journal of Advanced Computer Science and Applications  
The new improved algorithm is more efficient and more accurate than other algorithms.  ...  Developments in the past few decades have enabled human to automatically do the identification process.Now, face recognition process employs the advanced statistical science and matching methods.  ...  Accordingly, the images are used for matching process. Again, the two nearest neighbors can be employed for the discussed process. III.  ... 
doi:10.14569/ijacsa.2016.070175 fatcat:cnumzdpskbg2fhc2sphcuqpqaa

Application of Selected Geometrical 3D Object Description Algorithms to the Problem of Model Retrieval

Dariusz FREJLICHOWSKI
2015 Przeglad Elektrotechniczny  
Extended Gaussian Image and Shape Histograms. They are compared with a method based on the transformation of points from Cartesian to spherical co-ordinates.  ...  The current rapid development of computer hardware makes the processing of 3D scenes faster. Hence, the description of objects in image processing, recognition and indexing is possible.  ...  The transformation is performed using the formulas: (8) . lim In the proposed approach for the description of a 3D object the radial distances were chosen, since they turned out to be the most efficient  ... 
doi:10.15199/48.2015.02.25 fatcat:oie2arbsxngazolcxwcwo7vldy

An efficient image similarity measure based on approximations of KL-divergence between two gaussian mixtures

Goldberger, Gordon, Greenspan
2003 Proceedings Ninth IEEE International Conference on Computer Vision  
Continuous probabilistic image modeling based on mixtures of Gaussians together with KL measure for image similarity, can be used for image retrieval tasks with remarkable performance.  ...  The first method is based on matching between the Gaussian elements of the two Gaussian mixture densities. The second method is based on the unscented transform.  ...  Image modeling via a mixture of Gaussians is reviewed in section 2. In section 3 we propose an easily computed approximation of the KL-distance between two mixtures of Gaussians.  ... 
doi:10.1109/iccv.2003.1238387 dblp:conf/iccv/GoldbergerGG03 fatcat:44rtbpdyy5cgznpgaqzr24pdvu

Fast L1 Gaussian convolution via domain splitting

Shin Yoshizawa, Hideo Yokota
2014 2014 IEEE International Conference on Image Processing (ICIP)  
This paper proposes a fast and accurate approximation algorithm to convolve a L 1 Gaussian function with images.  ...  Our new algorithm is based on splitting a pixel domain into representative regions where we can efficiently perform discrete convolutions.  ...  Our main idea is to use the L 1 norm instead of the popular L 2 norm for distances between image pixels.  ... 
doi:10.1109/icip.2014.7025588 dblp:conf/icip/YoshizawaY14 fatcat:hrg45gut5jc3jgwog3e463n5qe

Corner detection using the point-to-centroid distance technique

Shizheng Zhang, Luwen Huangfu, Zhifeng Zhang, Sheng Huang, Pu Li, Heng Wang
2020 IET Image Processing  
Corners, highly important local features of images and corner finding, play a crucial role in computer vision and image processing, such as object tracking and vehicle detection.  ...  Extensive experimental results demonstrate that the PCD technique is effective and simultaneously efficient for corner detection compared with six other contour-based corner detectors in terms of two commonly  ...  image and its transformed version.  ... 
doi:10.1049/iet-ipr.2020.0164 fatcat:x2mgln2lj5dv5k6yjwlxeuppny

Recent Block-based Methods of Copy-Move Forgery Detection in Digital Images

Resmi Sekhar, Chithra A. S
2014 International Journal of Computer Applications  
Because of the developments in the field of Image Processing, altering images according to ones need is not a difficult task. Techniques of Image Forensics play its crucial role at this juncture.  ...  A copymove forgery is performed by copying a region in an image and pasting it on another region in the same image, mostly after some form of post-processing like rotation, scaling, blurring, noise addition  ...  These features are invariant for post-processing operations like additive white Gaussian noise.  ... 
doi:10.5120/15524-4331 fatcat:34f3llpfgrctri247krm5hmenm

Hausdorff-distance enhanced matching of Scale Invariant Feature Transform descriptors in context of image querying

J.I. Olszewska, D. Wilson
2012 2012 IEEE 16th International Conference on Intelligent Engineering Systems (INES)  
In this paper, we propose to integrate the Hausdorff distance matching together with our pairing algorithm, in order to obtain a robust while computationally efficient process of matching feature descriptors  ...  for image-to-image querying in standards datasets.  ...  In this paper, we propose to integrate the Hausdorff distance matching together with our pairing algorithm, in order to obtain a robust while computationally efficient process of matching feature descriptors  ... 
doi:10.1109/ines.2012.6249809 fatcat:cm2m7v3mdbcgbpbcoqbjoz5he4

Non-local fringe image filtration: a new interferometric data filtration paradigm?

Maciej Wielgus, Krzysztof Patorski
2012 Photonics Letters of Poland  
In this letter we discuss the notion of non-local filtration in the context of fringe pattern images processing, to contrast it with commonly used denoising techniques restricted to the close neighborhood  ...  We evaluate the performance of the nonlocal means algorithm on exemplary fringe patterns to compare it with several other methods and show filtration efficiency influence on phase calculation quality.  ...  Such a component is subsequently processed with the Hilbert transform or some kind of its 2D generalization. In these investigations, particularly, a vortex transform [9] was used for that purpose.  ... 
doi:10.4302/plp.2012.2.09 fatcat:a6za2dhzwfdyppdopctoqtcpwe

Fast L1 Gauss Transforms for Edge-Aware Image Filtering
Быстрое L1-преобразование Гаусса для сглаживания изображений с сохранением границ

D.R. Bashkirova, S. Yoshizawa, R.H. Latypov, H. Yokota
2017 Proceedings of the Institute for System Programming of RAS  
to computer vision and image processing tasks.  ...  In this paper, we propose a novel approximation method for fast Gaussian convolution of two-dimensional uniform point sets, such as 2D images.  ...  Acknowledgements We would like to thank the anonymous reviewers of this paper for their valuable comments.  ... 
doi:10.15514/ispras-2017-29(4)-4 fatcat:pohpyw57qfhwflniwnp6w3oyoe

Noise Removal of MRI Images with Different Similarities using Advance NLM Filtering

2019 International journal of recent technology and engineering  
Magnetic Resonance Imaging (MRI) is most effective and safe method for internal structure diagnosis. MRI images are generally magnitude images and they are follows by Rician distribution.  ...  Different distance matrix calculations have been introduced like Euclidean distance, Minkowski distance, Manhattan distance etc.  ...  RICIAN NOISE MODEL The MRI is complex image. It is represented by Gaussian distribution [2] [6] . The magnitude image is generally considered for its representation.  ... 
doi:10.35940/ijrte.c6647.098319 fatcat:364l3lmeyrft5chcklqzo3ouf4
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