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Creating a Gaussian Pyramid

I'm trying to recreate a gassuain pyramid using the following scales: There seems to be two concepts used here: 1) When an image is halved, applying a gaussian kernel of σ will apply as 2σ. 2) When ...
JustinBlaber's user avatar
2 votes
0 answers
185 views

Affine detector + SIFT descriptor

I am approaching to the Oxford Buildings dataset which contains already computed SIFT descriptors from affine detected keypoint locations. Usually SIFT detector provides to its detected keypoints ...
Andres Felipe's user avatar
1 vote
0 answers
78 views

Are there algorithms that can match SIFT's key points of 2 images using their mutual arrangement?

I'm solving image matching task using SIFT as a feature extractor To match obtained descriptors I used FLANN based Matcher (provided by OpenCV) and result looks good: But applying same algorithm to ...
Dmitriy Simonowich's user avatar
1 vote
0 answers
33 views

feature extraction techniques for iris recognition

I want to ask how I can divide feature extraction techniques to feature detectors and feature descriptors. I have big problem how to understand it. For example I can use Gabor filters (feature ...
Olo's user avatar
  • 73
1 vote
1 answer
334 views

How to obtain the relative position (coordinates) of SIFT feature from image center coordinates?

I have extracted SIFT features (keypoints and descriptors) of training set and saved in an inverted index form. My question is how can I calculate the coordinates of each visual features in an image ...
S.EB's user avatar
  • 163
1 vote
0 answers
271 views

VLFEat: How to extract the SIFT descriptor without SIFT feature detection?

I am using the MATLAB interface to the VLFeat toolbox in order to calculate a SIFT descriptor for image patches extracted around key points. Due to the greater framework of what I'm doing, I cannot ...
Michael's user avatar
  • 243
1 vote
0 answers
54 views

Analytical expression for salient Blob detection in scale space

I am working on exact mathematical expression which can be obtained in image processing tasks.(I do not know much about image processing but my work is more mathmatical) In Gaussian scale space, we ...
MUH's user avatar
  • 111
1 vote
0 answers
74 views

Geometric models to discard image features

I am working on the implementation of a location recognition pipeline as detailed in the section 5.4 of the paper Leveraging 3D City Models for Rotation Invariant Place-of-Interest Recognition: ...
Andres Felipe's user avatar
0 votes
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How orientation is used in FAST features in ORB?

I was going throught ORB paper. It states that it adds an efficiently computed orientation to FAST features. The description explains how it calculates Moment of patch $$m_{pq}=\sum_{x,y}x^py^pI(x,y)$...
Mahesha999's user avatar
0 votes
0 answers
94 views

SIFT between 1 image and dataset (2 images)

I use SIFT, and I want to find the angle of inclination of an image compared to two reference images, in short: I have 3 images : Image x: input image Two images 1 and 2, reference images that are ...
all.west's user avatar
0 votes
0 answers
46 views

Counting percentage of fouling on a surface

I am completely new to image processing and python. I hope I can find some help here. I am trying out a project on detecting fouling% on a ship hull using raspberry pi. I am trying to learn how this ...
Jeremy.J's user avatar
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659 views

Distance-metric for SIFT descriptors matching

Will using Cosine-Similarity or Histogram Intersection as distance-metric, for matching SIFT descriptors, help to get better results? Anybody tried on that ever?
Ankit Nayan's user avatar