Questions tagged [feature-detection]

Feature detection is a process in computer vision that aims to find visual features within the image with particular desirable properties. Detected features can be points, image regions or continuous curves in the image. Interesting properties can include invariance to noise, perspective transformations, or properties interesting for specific usages (e.g. tracking).

Feature detection is a process in computer vision that aims to find visual features within the image with particular desirable properties.

Detected features are some subsection of the image, and can be:

  • points (e.g. Harris corners)
  • connected image regions (e.g. DoG or MSER regions)
  • continuous curves in the image

Interesting properties can include invariance to noise, perspective transformations and viewpoint changes (camera translation and rotation), scaling (for use in visual feature matching), or properties interesting for specific usages (e.g. visual tracking).

Important information about visual features can include:

  • coordinates in the image
  • radius of the visual feature
  • scale (octave) of the image on which the feature has been extracted

After detecting the feature with some feature detection algorithm, it is usually described by a descriptor vector (several known descriptors are used today) for the purposes of visual feature matching, while the feature's position in the image can be used directly for application in tracking.

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DataSets and Background Subtraction

I am working on a Project that has to detect vehicles and classify them according to their shape (Pickup,Muv,Sedan,etc). Its my minor project and I need to submit it in a month(obviously not much time left) I am confused that should I use Image or…
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Open CV feature detection in GPU

I'm using OpenCV 2.4.6 in a prototype of object detection and I was wondering in how to improve the feature detection/extraction performance. Someone knows if is it possible to run feature detection/extraction/matching, like SIFT/SIFT/BF, or even…
Oberdan Nunes
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background detection having font with same color as background

I have image as following (so, this is white figure on red background. This figure have two thin red lines inside it) and I want to receive following image (remove red background but not two red lines inside figure) I was trying convexHull from…
Arsen
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Determine whether `window.close` is a valid function

I'm producing a page which will most often be opened via an anchor with target="_blank". Progressive enhancement AJAXes in the page and places it within a modal, in which case the close button removes the modal node from the tree — in these…
Barney
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STASM how face feature detection works

i'm trying to work on STASM but the manual doesn't really explain how it works, i want to understand how does ASM detect the face feature in STASM. can you please help me. thank you
user2425049
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OpenCV - How to implement FeatureDetector interface

I am using the C++ implementation of OpenCV 2.4.6.1 for Ubuntu 12.10 on a x86_64 architecture. I am working on wrapping this code of the Agast Corner Detector inside a class inheriting from cv::FeatureDetector. Inspecting the feature2d module header…
Andres Felipe
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Android OpenCV FeatureDetection -> runFeatureHomography giving messed up result image after matching

I'm pretty new to openCV, and at the moment im tryin to get an object detection running on an android device. What i basically do, is displaying a a camera preview in my app, and when i click on it it captures a picture. Then this picture is given…
user2677466
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Active frame extraction from motion capture

I am new to this area - I have a background in a Gait and Posture. I have a series of motion files of timestamped coordinates (containing X, Y, and Z in mm) with a number of joints (30). What would be the simplest way to extract the following from…
Daniel
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Feature Extraction for training

I am having trouble in using feature extraction for object classification. I need to classify different types of cars but I do not know which feature extraction technique to use for training purpose. In short How can I conclude that (Lets say)…
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Finding the distance between two photos of the ceiling using SIFT

I am currently writing a project that will allow robot to find its location depending on the photos of the ceiling. The camera is mounted on the robot and is facing the ceiling directly (meaning that the center of the photo is always consider to be…
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OpenCV: How to compare the performances of feature detectors and extractors using images of a real scene by different point of view?

I'm trying to build a loop closure algorithm, but before to start the development I would like to test which feature descriptor work better on a real dataset. I have a pair of images of a corridor taken in both direction, one entering in a room and…
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How to compute features using DAISY feature extractor?

I am wondering if somebody has used DAISY features for object recognition problems? Link to DAISY (MATLAB one) is: http://cvlab.epfl.ch/software/daisy My question is how to use this software (MATLAB) to get keypoints and their descriptors? I can…
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Can Viola-Jones face detection in opencv works for 25 feet?

Can Viola-Jones face detection in opencv works for 25 feet? If the camera is good and capable of good quality picture is it possible for Viola-Jones to detect the face?
2vision2
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Detecting object class using shape descriptors in computer vision

I want to differentiate between two classes of objects through the differences in the shape of blob(blob is in the form of binary image) using shape descriptors and machine learning .I want to ask if there is any good shape feature which I can use…
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Training set selection of ORB (Oriented fast and Rotated Brief) feature descriptor

I am working on my implementation of the ORB descriptor. I went trough the paper but I am finding hard to understand how to select the training set that is used on their learning method to select a good subset of binary tests. If I have a single…
Andres Felipe
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