surf

问题 I am a newbie at opencv and python and am trying to collect keypoints and descriptors of faces within an image. I am using HAAR cascade classifier with frontal face template to look for faces in an image. The HAAR cascade gives me a list of coordinates marking the faces in the image. I want to generate a "mask" at those coordinates so that I can use cv2.surf() to extract keypoints and descriptors within the masked region. I don't know how to create that mask. Try this photo as an example to

问题 I am a newbie at opencv and python and am trying to collect keypoints and descriptors of faces within an image. I am using HAAR cascade classifier with frontal face template to look for faces in an image. The HAAR cascade gives me a list of coordinates marking the faces in the image. I want to generate a "mask" at those coordinates so that I can use cv2.surf() to extract keypoints and descriptors within the masked region. I don't know how to create that mask. Try this photo as an example to

问题 I am a newbie at opencv and python and am trying to collect keypoints and descriptors of faces within an image. I am using HAAR cascade classifier with frontal face template to look for faces in an image. The HAAR cascade gives me a list of coordinates marking the faces in the image. I want to generate a "mask" at those coordinates so that I can use cv2.surf() to extract keypoints and descriptors within the masked region. I don't know how to create that mask. Try this photo as an example to

问题 Closed . This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed last month . Improve this question I try to use the SIFT and SURF function with some of the versions of OpenCV 3 and openCV 4 (after having installed opencv-contrib-python) with: pip install opencv-contrib-python i try version 3.4.3 and 3.4.9 and 4.1.0, but have same probleme: sift = cv2.xfeatures2d.SIFT_create(

问题 Recently I want to work with SURF in opencv, but when I instelled I don't activate the option to have access to the extra modules. So, I donwloaded from https://github.com/opencv/opencv_contrib and then, I followed the steps for installation in: add extra modules to opencv python? But when I ran the commands for the first time I got: CMake Error at CMakeLists.txt:11 (message): In-source builds are not allowed” in cmake I was read some about it and the problem cames from CMakeCache.txt and has

问题 for my master thesis, i am running some test on the SIFT SURF en FAST algoritms for logo detection on smartphones. when i simply time the detection, description en matching for some methods i get the following results. For a SURF detector and SURF descriptor: 180 keypoints found 1,994 seconds keypoint calculation time (SURF) 4,516 seconds description time (SURF) 0.282 seconds matching time (SURF) when I use a FAST detector in stead of the SURF detector 319 keypoints found 0.023 seconds

问题 How to draw a Geosphere in matlab? By Geosphere I mean the way of discretization points on a sphere (Geosphere is, for example in 3Ds Max). On the image below, it is shown Sphere (on the left) and Geosphere (on the right) In Matlab there is a function sphere , which gives such a result: I need to get such an image of a Geosphere. I have a matrix Nx3, with xyz coordinates of every point of Geosphere. UPDATE: I had problem only with displaying (drawing) geosphere, because I already have data -

问题 I am using this code in Python: from selenium import webdriver from selenium.webdriver.firefox.firefox_binary import FirefoxBinary binary = FirefoxBinary(r'C:\Program Files (x86)\Mozilla Firefox\firefox.exe') driver = webdriver.Firefox(firefox_binary=binary) driver.get("www.google.com") Unlucky, this open Firefox but not the URL (not return any error). Do you know why? 回答1: If you are using Selenium 3.x along with the recent Frirefox Quantum browsers, you have to download geckodriver.exe from

问题 How do I speed up the correspondence matching processes of SURF? I used the samples provided and changed it to capture color images from the webcam for processing, however, the speed certainly needs improvement. Where should this be tackled on? 回答1: First, SURF (at least, OpenCV's one) supports only gray images. There are lots of descriptors parameters avalable to tune, setting them to lower values can increase performance: typedef struct CvSURFParams { int extended; // 0 means basic

问题 Which method is the best to compare two images and discard outliers points? In find_obj.cpp opencv example, they use FLANN, but don't discard outliers. I have seen some methods like using Kmeans or graphs. 回答1: There is a fairly reliable and efficient way to both reject noisy points and determine the transformation between your points of interest. The algorithm that is usually used to reject outliers is known as RANSAC (http://en.wikipedia.org/wiki/RANSAC), and the algorithm used to determine