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Questions tagged [surf]

Speeded-Up Robust Features (SURF) is a feature detection algorithm used in many [tag:computer-vision] tasks, such as object recognition, 3D reconstruction, camera calibration, and [tag:cbir].

Speeded-Up Robust Features (SURF) is an algorithm in computer vision to detect and describe local features in images.

SURF is billed as specifically “Speeded-Up” and “Robust” over its predecessor, the SIFT algorithm – it is based on Hessian blob detection, and eschews the more byzantine arrangements of SIFT (e.g. octaves). This visualization illustrates SURF features with circles, scaled accordingly for each feature, overlaid on the image from which they were extracted:

SURF feature overlaid

The standard standard SURF implementation, from the introductory journal article, is about an order of magnitude faster than David Lowe’s implementation of SIFT (when run in a comparable environment).

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Error -215 trainDescCollection[iIdx] Python OpenCV

I'm matching two images and in the 80% of the cases works but in some cases it crashes and show up this message: ... matches = matcher.match(d1, d2) error: ......\opencv-2.4.6\modules\features2d\src\matchers.cpp:365: error: (-215)…
user3075816
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SIFT or SURF - Provide key points and retrieve descriptors

I am trying to use OpenCV(2.4.6.0) to retrieve descriptors from key points that I have provided. So far, I have not been successful... l, des = surf.detectAndCompute(self.gray,None,useProvidedKeypoints = True) where l is an array of feature points.…
user2268507
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Which feature detector algorithm is simplest for learning?

I am wrapping my head around feature detector algorithms. I've studied the options that I have: SIFT, SURF, BRISK, FREAK etc. All of them seem fairly complex in terms of underlying mathematics. On the contrary, I want to take one step at a time…
c0dehunter
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Different SURF Features Extracted Between MATLAB and OpenCV?

I'm implementing an algorithm in OpenCV that I've designed in MATLAB. I'm writing a unit test for the SURF feature extractor in OpenCV, and I want to compare the output of MATLAB's extracted SURF features to OpenCV. This issue is, using the same…
trianta2
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OpenCV 2.4.3 - warpPerspective with reversed homography on a cropped image

When finding a reference image in a scene using SURF, I would like to crop the found object in the scene, and "straighten" it back using warpPerspective and the reversed homography matrix. Meaning, let's say I have this SURF result: Now, I would…
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OpenCV for Android - training SVM with SURF descriptors

I need some help in training a SVM for an Android app. I have a set of images in different classes (12 classes) and got all descriptors from them. I managed to get the same amount of descriptors for each image. What I need is to train a SVM for my…
mtndg
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Python bindings for OpenCV with AttributeError: 'module' object has no attribute 'FeatureDetector_create'

I am using the python bindings for OpenCV 2.4.X and OpenCV 3.1 but with the following simple two-liner import cv2 detector = cv2.FeatureDetector_create("SURF") I get the following output: Traceback (most recent call last): File…
pevogam
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OpenCV features detection and matching - segfault on drawing matches

Following this example, I'm trying to build an application to recognize objects in a video. My program is composed of the following steps (see code sample of each step below): Read the image of the object to be recognized into a cv::Mat…
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OpenCV SURF keypoints Comparison

I have 2 image with a little bit orientation to left in camera, i want to find the orientation from opencv, i get surf keypoints from 2 image and my problem is how to compare this 2 keypoints to find orientation.
Mahyar
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Extract less keypoint with opencv

I need to do an object recognition in real time (with image coming from videocamera usb) Is there anyway to tell SurfFeatureDetector.detect(); to extract less keypoint ?
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Using SURF how to give result by saying this is the matching image?

I'm doing a project to recognize the value of currency note and i should return the value.I used SURF algorithm to detect the value.There are several templates of currency values and i match those templates with currency images which captured from…
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Problems with opencv feature descriptors converted from gpu feature descriptors

I've been having some problems with the conversion of a GPU feature descriptor matrix to a CPU feature descriptor matrix with openvc, using: void downloadDescriptors(const GpuMat& descriptorsGPU, vector& descriptors); As you can see, this…
Alberto A
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Detecting SURF features - disappointed by the performance

I was looking to extract SURF features (or something similar) in an application that gets new images at 25 FPS. I thought feature extracting would be possible at least close to real time. I tried OpenSURF with the same parameters that are supplied…
user1128760
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Why does the flann based descriptor matcher match to different keypoints everytime?

Is it normal? When I tried the brute force matcher, the result is consistent everytime, but flann is not. A small amount of keypoints will match to different places. I am writing the code using the Android wrapper, the keypoint detector and…
kaitik
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opencv image search

I'm aiming to search through a library of images using an image as the query. I want to use SURF and a customized NN technique to match relevant images and display the top ten results from that image. Once I get the SURF NN matching code working for…
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