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Questions tagged [vlfeat]

VLFeat is an open source library that implements popular computer vision algorithms

VLFeat includes implementations of HOG, SIFT, MSER, k-means, hierarchical k-means, agglomerative information bottleneck, SLIC superpixels, and quick shift. It is written in C for efficiency and compatibility, with interfaces in MATLAB for ease of use, and detailed documentation throughout.

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Import Error in __init__.py : No Module named _vlfeat in PyVlfeat

I am trying to run this python rewrite of Vlfeat library. https://github.com/shackenberg/phow_caltech101.py. I am trying to run the application phow_caltech101. This is throwing File "/A/B/C/pyvlfeat-0.1.1a3/vlfeat/__init__.py", line 1, in…
Erdnase
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relationship between SIFT keypoint orientation and SIFT description orientation

I am using VLfeat open source for extracting SIFT keypoints and their descriptions. The image below shows one of them. The yellow disc indicates the keypoint's scale (radius) and orientation (line). The green frame indicates its description (i.e.,…
YW P Kwon
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Why's Python's Hog output (scikit-image) different from MATLAB's Hog (vlfeat)?

I have a piece of MATLAB code which takes a 91x91 patch of pixels from an image and apples HOG to extract its feature vectors. I would like to rewrite the function in Python. I've been struggled for a while trying to find out how to get the same HOG…
Peine
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VL_SLIC MATLAB Output for VL_FEAT

I am using the VL_SLIC function in MATLAB and I am following the tutorial for the function here: http://www.vlfeat.org/overview/slic.html This is the code I have written so far: im = imread('slic_image.jpg'); regionSize = 10 ; regularizer =…
Dark Knight
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vlfeat nmake: fatal error U1073: don't know how to make "msvcr100.dll"

I have downloaded vlfeat source code. I am trying make file using nmake (Microsoft Visual Studio command) to use vlfeat. The command I have given is: nmake /f Makefile.mak ARCH=win32 It gives the following error. NMAKE : fatal error U1073: don't…
Sridhar Boganathan
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How can I build "C" VlFeat library for Android

I would like to use the "C" VlFeat (http://www.vlfeat.org/index.html) library for Android. Is there an official build? Is there a simple way for building it? Thanks, Israel Sadeh
user2399151
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SLIC c++ segmentation

Im trying to segment an image using SLIC in OpenCV. Im trying to use the following function: void vl_slic_segment ( vl_uint32 * segmentation, float const * image, vl_size width, vl_size height, vl_size numChannels, vl_size …
triple13
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Extract HOG from a single pixel using VLFEAT

I'm trying to extract points of interest to perform an image registration of clinical images. I've detected MSER from an image "I" using vl_mser: [R, F] = VL_MSER(...) which returns a region of seeds R and ellipsoids F. Now I would like to…
bongini.simone
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SIFT orientation normalization

I want to normalize the sift descriptors by rotating them so that the horizontal direction is aligned with the dominant gradient orientation of the patch. I am using vl_feat library. Is there any way in vl_feat to normalize the sift descriptos? or…
user570593
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Sift descriptor at particular pixel

I want to find the sift descriptor at a co-ordinate ( x ,y ) in the image with a patch size of 5X5 neighbour with the co-ordinate in the middle. The intention behind it is to analyse the orientation values that I get on that co-ordinate for further…
anon
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slow kd-tree queries using vlfeat, faster alternatives?

I'm using vlfeat's kdtree which implements the kd-tree from FLANN, which supposedly handles high dimension data. However, right now I have a kdtree built from a 128x15000 set of data and kd tree queries for anything has slowed down to 8 seconds a…
mugetsu
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Compiling vlfeat mex in octave: undefined symbol

I hope this question is not to specific. I am trying to compile the vlfeat library for octave 3.6.2. It compiles the mex-files without errors. But if I execute vl_setup vl_demo i get error: vl_demo_sift_basic: vl_sift.mex: failed to load:…
sietschie
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Matlab VLFeat - error: expected '=', ',', ';', 'asm' or '__attribute__' before 'void'

I'm trying to run a file called vl_compile.m for VLFeat and I am getting this error in regards to the mexutils.h header file: >> vl_compile vl_compile: assuming that Visual C++ is the active compiler vl_compile: compiling for PCWIN64 (64 bit) MEX…
Cizox
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setting the level of pyramid for VGG's VL_PHOW

Long time ago I applied a old version of a PHOW library (https://www.robots.ox.ac.uk/~vgg/research/caltech/) with very good results for training a neural net. Nowadays I would like to test the new version embedded in VL_phow, but I couldn't find…
Gilmario Santos
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How to setup VLFEAT on Octave?

The instructions on the official website aren't clear. Does anyone know how to setup VLFEAT on Octave(Windows)?
Aditya Jain
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