Why does simultaneously running two video writers produces a distorted output...
I'm trying to produce 2 video files from a single RTP stream using OpenCV. The 2 files should each have 30 seconds length with the first 10 seconds of the 2nd file containing the last 10 seconds of...
View ArticleData set with known camera parameters
I am looking for a data set containing images of pedestrians/cyclists with static background and given camera calibration information (intrinsic and extrinsic) for a scene. I have already found EPFL...
View ArticleMost efficient way to avoid clustering with FAST ? (for ORB feature extraction)
I am implementing the ORB feature extraction algorithm, and I have my own FAST implementation. As the paper clearly states, there is no measure of "cornerness" in FAST, which is why Harris is used to...
View ArticleHomography estimation when feature matching fails
Hi all, I'm pretty new to openCV and CV in general. I want to align images of football pitches to a basic template of the pitch. I've managed to find a reasonable way of processing the full pitch...
View ArticleOptimize feature detection and tracking
Hi all, I'm newly getting into OpenCV and don't quite know how to ask that question. I'm analyzing a video stream to find a picture inside the video frame and then I track the movement of the picture...
View ArticleHow to install opencv 4.1 using CMake and Visual Studio 2013?
Hi, I am trying to install OpenCV 4.1 using CMake with Visual Studio 2013 in 64 bits. I use this tutorial https://docs.opencv.org/3.4/d3/d52/tutorial_windows_install.html to install OpenCV 4.1. I...
View ArticleImRead hit error when your file name first character is numeric value
Hi Guys, I am having issue when reading the file name if i manually add B_ in front of 203.png, it is working cap = cv2.imread(str('Images\Beadchips\Grade F\B_203.png'),1); if i didnt add any...
View ArticleOpenCV4.1.2 build with visual studio 2013 is it possible?
am trying to compile opencv 4.1.2 c++ for visual studio 2013 x64. I was able to do so very quickly for VS2017, however not for 2013. does any body know if openCV 4.1.2 is not compatible for visual...
View ArticleDoes opencv_dnn use gpu?
I tried to run the code in Jetson GPU but I can't? I just obtained 5 fps, this means that use CPU not GPU this is my full code from imutils.video import VideoStream from imutils.video import FPS import...
View ArticleIssue building OpenCV 3.4.3 for Android
Hi, I'm following a guide to build OpenCV 3.3.x for Android on Windows (http://amin-ahmadi.com/2017/08/13/how-to-build-opencv-3-3-x-for-android/) and I've followed all the steps in it, but the...
View ArticleIssue building OpenCV 3.4.3 for Android
Hi, I'm following a guide to build OpenCV 3.3.x for Android on Windows (http://amin-ahmadi.com/2017/08/13/how-to-build-opencv-3-3-x-for-android/) and I've followed all the steps in it, but the...
View ArticleObject Segmentation method
Hello, I need your help, I have an image, and I want to extract the red part of this image (contours), my idea is giving the user the possibility to select a point inside the red part and use this...
View Articleicon location question
Hey All, I would like to know if it is possible to detect whether an object/icon is closer to point A or point B on a 2D surface? The object or icon is not moving. so just static. And if so, is it...
View ArticleForeground extraction
Hi All, I am having an image as enclosed taken through a DSLR camera but its background is also seen on which the object is placed. I want to crop the object from the background. I tried a variety of...
View ArticleGenerate a mask for FAST keypoints in c++
im trying to use a mask to compute SIFT descriptors. The idea is the following: - Detect keypoints with FAST - Create a mask with those keypoints - Pass that mask in the detectAndCompute method of the...
View ArticleFastest way to convert BGR RGB! Aka: Do NOT use Numpy magic "tricks".
---------- **IMPORTANT:** This article is **very** long. Remember to click the `(more)` at the bottom of this post to read the whole article! ---------- *I was reading this question:...
View ArticleFeature extraction 3D
Please my case is as follows, I have and adjacency matrix(Graph data structure, 0-1) it's originally mesh having 3d coordinates (XYZ). Now the idea is that I want to extract features, but I read that...
View Articlewhere is cvCreateTrainingSamples() function?
looking thru createsamples.cpp and noticed that cvCreateTrainingSamples() is called, but isnt in the code and also couldnt find it in any of the #include files. i am new to c++ but have experience in...
View ArticleTypes of Mats and decision making
Hi, I know that Mat has many different types, as detailed below. Its puzzles my how one should decide which one of those to choose ?. Just image quality ? what is the correct way to convert from one to...
View ArticleRolling ball / Sliding paraboloid algorithm
The Rolling ball / Sliding paraboloid algorithm is a well know singular background subtraction approach. It seems this would be a worthwhile addition to OpenCV. This is a fundamental and potentially...
View Article