edge directions, even without precise knowledge of the corresponding gradient or edge positions. In practice this is implemented by dividing the image window into small spatial regions (“cells”), for each cell accumulating a local 1-D histogram of gradient directions or edge orientations over the pixels of the cell. The combined histogram entries form the representation. For better invariance to illumination, shadowing, etc., it is also useful to contrast-normalize the local responses before using them. This can be done by accumulating a measure of local histogram “energy” over somewhat larger spatial regions (“blocks”) and using the results to normalize all of the cells in the block. We will refer to the normalized descriptor blocks as Histogram of Oriented Gradient (HOG) descriptors. Tiling the detection window with a dense (in fact, overlapping) grid of HOG descriptors and using the combined feature vector in a conventional SVM based window classifier gives our human detection chain (see fig. 1).
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Surface uniformization means that all metric surfaces can be conformally mapped to one of the three canonical domains, the sphere, the plane and the hyperbolic space. The figures show the uniformization for surfaces with various topologies. Unformization converts general 3D geometric problems to 2D problems in these canonical domains. Ricci flow is a powerful geometric analytic tool, which has been applied to prove Poincare conjecture. Ricci flow is a parabolic system of partial differential equations which acts like the heat equation to spread the curvature of a Riemannian metric evenly over the surface to produce a metric of constant curvature. Computational discrete Ricci flow is the practical method to compute surface uniformization, it has many important applications in many engineering fields.
Histogram of Gradients of Time-Frequency Representations ...
ieeexplore.ieee.org/.../0697...
Institute of Electrical and Electronics Engineers
by A Rakotomamonjy - 2015 - Cited by 7 - Related articles
Nov 22, 2014 - Histogram of gradients; Time-Frequency Representation; audio scene; MFCC; ... Transactions on Audio, Speech, and Language Processing. 2.Presents our entry to the Detection and Classification of Acoustic Scenes challenge. The approach we propose for classifying acoustic scenes is based on transforming the audio signal into a time-frequency representation and then in extracting relevant features about shapes and evolutions of time-frequency structures. These features are based on histogram of gradients that are subsequently fed to a multi-class linear support vector machines.
Histogram of oriented gradients - Wikipedia, the free ...
https://en.wikipedia.org/wiki/Histogram_of_oriented_gradients
The histogram of oriented gradients (HOG) is a feature descriptor used in computer vision and image processing for the purpose of object detection.
Wikipedia
Progress report
www.cis.rit.edu/.../progres....
To find edge information, gradient operators (first derivative and second ... Laplacian operator gives useful information about whether a pixel is on the dark or light side of an edge. ... I created a program by IDL language to get these results. ... Simply select a threshold value between peak values from a histogram plot and set ...
Chester F. Carlson Center for Imaging Science
[PDF]Image Enhancement by Gradient Distribution Specification
mosaic.mpi-cbg.de/docs/Gong2014.pdf
by Y Gong - Cited by 5 - Related articles
for image enhancement is histogram equalization or one of its variants. ... Among all second order operators, the Laplace operator is the most attractive one.
Missing: language
[PDF]A Nonlinear Laplace Operator as Edge Detector in Noisy ...
https://pdfs.semanticscholar.org/.../c274677dadd21f1e97cd0d37738a1da...
by LJ VAN VLIET - 1989 - Cited by 132 - Related articles
(1) detectors that approximate the mathematical first derivative (gradient) or the ... In 1986 Beckers [18] proposed a nonlinear Laplace-like operator in a local 3 X 3 ..... with the help of a window search or a histogram search algorithm (Huang [28], Duin. ~291). ..... All of the programming was performed in the C language.Edge Detection with Gradients: Part 01 - Gradient ... - YouTube
https://www.youtube.com/watch?v=j7r3C-otk-U
Sep 5, 2012 - Uploaded by vkedco
1) Definition of gradient 2) Pixel neighborhoods in gradient ...Histogram of Oriented Gradients (HOG) for ...Scale Invariant Feature Transform - Scholarpedia
www.scholarpedia.org/.../Scale_Invariant_Feature_Transfor...
Apr 21, 2015 - 5.1 Receptive field histograms; 5.2 Histograms of oriented gradients(HOG) ... constitutes an approximation of the Laplacian operator\[DOG(x, y; ...
Scholarpedia
Missing: language
[PDF]Chapter 3 Local Features: Detection and Description
www.cs.utexas.edu/.../local_features_synthe...
The Harris-Laplacian operator [MS01, MS04a] was proposed for increased discrim- .... the image information in a localized set of gradient orientation histograms.
University of Texas at Austin
Missing: language
Calculate the gradient for an histogram in c++ - Stack Overflow
stackoverflow.com/questions/.../calculate-the-gradient-for-an-histogram-i...
Dec 29, 2009 - Now I would like to calculate the gradient for the this histogram at .... of image algorithm here like Laplace [-1 2 -1] - Laplace operator can be ...[PDF]Filtering and Enhancing Images
https://courses.cs.washington.edu/.../ch5.pdf
from larger uniform regions; secondly, it was shown how a contrast operator .... by advancing i in the input image histogram until approximately q1 pixels are accounted ..... (b) Implement your algorithm in some programming language ..... The gradient of the picture function can be estimated by applying the masks to the 8-.
University of Washington
Advanced Biomedical Image Analysis - Google Books Result
https://books.google.com/books?isbn=1118099486
Mark Haidekker - 2011 - Science
... 141 Laplacian distribution, 399 Laplacian operator, 33 Laplacian-of-Gaussian, ... 458 local forces, 179 local gradient, 147, 199 local histogram equalization, ... 381 LZ compression, 396 LZW encoding, 396 macro scripting language, 444, ..
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