Keypoints in very small images
I want to find a very small image (20x20px) within a small image (~400x250) using OpenCV. Here is an example: [small image](https://ibb.co/d68TCa) [very small image](https://ibb.co/f9qasa) The problem...
View ArticleMat.get equivalent for C++?
I'm trying to duplicate an example for line detection from java to native code. My Java code is as follows int[] linesArray = new int[lines.cols() * lines.rows() * lines.channels()];...
View ArticleTheroy required for Video Analysis
Hi I would like to work on a project on video analysis with opencv. What are the prerequisite theory should I get familiar to start. Or could you share your experience please? Thanks
View ArticleTrain cascade accelerated by gpu
Hi, I want to know that can I use opencv traincascade accelerated by my nvidia gpu, I have installed cuda toolkit 8.0 and have build opencv with cuda everything is good. But when I'm training it is...
View ArticleChain code and xml
Hello, i am having a problem when saving the xml file.. Only a single row is being showed in the xml..but, i want to retrieve several rows with valid values to represent the images found in the...
View Articleopencv python merge different channel images into one
I have few satellite images each of them represents one channel of main satellite image, these are 11 images in total, each are labled with different channel, all images are in .tiff format with...
View ArticleUpdate opencv viz3d window after calling spin() (event loop)
I made a program based on the user inputs some widgets appear inside viz3d window. the problem is I want the widget's pose to get updated real time so the program should do the following: 1- take...
View Articleface detection / recognition not working
hey guys, im trying to write a program, which detecs and recognizes faces. i tried a lot, but somehow i cant get it to work. maybe you can help me out a bit: im using: python 2.7 and opencv 2.4 import...
View ArticleOpenCV help on positions
Hey guys Im new to opencv, I have this image:  I have already detected green and blue colors using HSV, but Im stuck in determining the position of...
View Articledetect nail from image
i want detect nail size from image how remove noise and detect nail  Use the code below: Mat binary; Mat image = imread("img/nail3.jpg"); if...
View ArticleLoading a pre-trained KNN classifier - python
I know there is a save command for the KNN classifier, that outputs the model in XML. Is there any corresponding load command to load that model back into python I am using cv2 3.0.0 and Python 2.7
View ArticleANN in opencv 3
Hi, I was trying to run this example found in this forum: #include using namespace std; using namespace cv; using namespace cv::ml; int main(int argc, char* argv[]) { //create random training data...
View ArticleRead h264 RTP stream with libvlc and process it with OpenCV
Hi everybody ! I want to read stream from ipCamera in h264 1920*1072 and process it using Opencv. I tried the easy way with videoCapture("rtp://myadress") but the image is very bad and i have error...
View ArticleNeed Code: Android OpenCV camera2 capture application
Hello all. I need a simple reference to a code that opens the camera device using API android.hardware.camera2 , and pass the frame to a Mat object for OPENCV processing. All the code I manage to find...
View Articleknn train erro
Mat m = Mt.converterParaMat(Mt.imagemFinal); m.convertTo(m, CvType.CV_32F); Imgproc.resize(m, m, tamanho);//tamanho 120x120 m = m.reshape(1,200); //tamanho 200x216 trainDados.push_back(m);...
View ArticleProblem in installation of Opencv in ubuntu 16.04
Hi, I was trying to install OpenCV, by using opencv.sh copied from the web page https://help.ubuntu.com/community/OpenCV. It is showing the following error while executing the command "make"....
View ArticleDuplicate camera.
Hi everyone! I want to make an app in Android using opencv to apply filters in Camerapreview. My problem is that is a VR aplication (using a google cardboard) and I need to duplicate the camera...
View ArticleHow is the EMDL1() function different from EMD() function in OpenCV?
What is the difference between EMDL1() and EMD() function in OpenCV? What does 'L1' signify? Please provide suggestions.
View ArticleMeaning of Output of Artificial Neural Network
I have successfully trained ANN. I have tested it with one of the training sample as shown below and it gives me two outputs:- Mat_ output; float out = ann->predict(hists.row(8), output); cout...
View ArticleSet multiple rows and single column at the same time in Matrix
Hi, i'd like to know how to set multiple rows and single column at the same time in Matrix. Ex: Mat my_matrix = Mat::zeros(100, 4, CV_32S); suppose that I want to set: - rows 0-24 column 1 as 1; - rows...
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