Questions tagged [feature-detection]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0 votes
0 answers
15 views

Understanding Scale-space extrema detection in SIFT

Why do we say that minima in the scale-space domain make for good key points? It makes sense for maxima to be considered, but why do we consider it if it's a minima? This does not cohere with my ...
user avatar
  • 257
0 votes
0 answers
21 views

Where is the Hessian matrix computed in SURF?

I understood that, in SIFT, the Hessian matrix is used to remove edges from previously detected keypoints. Hence, if I understood well, in SIFT the Hessian matrix is computed only in the locations ...
user avatar
1 vote
0 answers
24 views

Feature extraction for IRIS recognition

What are types for feature extraction in iris recognition? How can I divide it on types which detect phase, edge, etc.?
user avatar
  • 83
1 vote
0 answers
20 views

ORB Implementation, Scale Pyramid, rFAST

Reading this ("ORB: An efficient alternative to SIFT or SURF") paper, I am not certain how they use the scale pyramid. It says it is created and FAST feature detectors are employed at every ...
user avatar
1 vote
1 answer
80 views

Corner detector vs feature detector

In the literature, I see "corner detector" and "feature detector" are interchangeably used for these methods e.g. Harris, Shi-Tomasi, FAST, etc. What is the difference between a ...
user avatar
0 votes
1 answer
57 views

Feature detector vs dense detector

What is the difference between a feature detector and a dense detector in computer vision? Are they the same or a subset of one another? For the following algorithms (implemented in OpenCV), which of ...
user avatar
2 votes
1 answer
80 views

Palmprint Identification - Why do we align the images before we use the Fourier Transform?

I was reading the paper PALMPRINT IDENTIFICATION BY FOURIER TRANSFORM by WENXIN LI, DAVID ZHANG and ZHUOQUN XU about identifying persons based on an image of their palm. The first step in their ...
user avatar
  • 183
0 votes
0 answers
23 views

Finding the differences(using features, not subtraction) in order to find differences in signals

I have a question. Let’s say I have two signals (discretely represented as arrays), $S_1$ and $S_2$ as shown below. $S_1$ has a similar form to $S_2$. If the signals are subtracted, $S_2-S_1$, they ...
user avatar
1 vote
0 answers
37 views

KLT tracker, reject tracked occluded points

I want to use KLT tracker for a visual odometry application. Thus, I only want to track object features. Currently I'm using OpenCV's implementation ...
user avatar
0 votes
1 answer
34 views

What are the ranges of values for each audio feature/descriptor?

I need to normalize some audio feature measurements I've done with the software Wolfram Mathematica. Coming from a non signal processing background, I have some difficulties understanding what ...
user avatar
1 vote
1 answer
55 views

Is there any way to do 3D (Voxel Data) feature detection?

In the 2D image processing, there are ways to find and match features of the image (like corner of the edges). However, I could not find the equivalent of that in the 3D-voxel data (Here voxel means a ...
user avatar
1 vote
2 answers
685 views

Scratch Detection On Noisy Textured Surface

I wish to extract long thin scratches from the noisy background image.I have tried several ways such as stacking smoothed image with input image to remove some of the noisy background patch before ...
user avatar
0 votes
1 answer
64 views

How to make series circle shift invariant

I have a series of numbers. They may be integer, floating, or ...
user avatar
2 votes
2 answers
549 views

How to extract features of individual spikes in non-negative signal?

I have data of non-negative (in the sense there's no signal below baseline) spiking waveforms, which are in the form of a 1D array of numbers: Spikes that cross some threshold are considered real ...
user avatar
4 votes
2 answers
5k views

ORB Algorithm: What Is Intensity Centroid?

So, I am reading a paper about ORB: An Efficient Alternative to SIFT or SURF and it happens to calculate the direction of corner from it center . According to Rosin the author of the paper;moments of ...
user avatar
  • 394