Using pure OpenCV API calls: // Declare what you need cv::FileStorage file(“some_name.ext”, cv::FileStorage::WRITE); cv::Mat someMatrixOfAnyType; // Write to file! file << “matName” << someMatrixOfAnyType; The file extension can be xml or yml. In both cases you get a small header that you can easily remove/parse, then you have access to the data in a floating … Read more
I’ve talked about this so many times before, I guess it’s pointless to do it again, but code defensively: if a method/function call can fail, make sure you know when it happens: Mat I = imread(“C:\\images\\apple.jpg”, 0); if (I.empty()) { std::cout << “!!! Failed imread(): image not found” << std::endl; // don’t let the execution … Read more
You can get elements from Mat by copying unmanaged memory blocks using DataPointer and converting managed to unmanaged types. Setting values is marshaling in the opposite direction. For an example you can use such an extension class public static class MatExtension { public static dynamic GetValue(this Mat mat, int row, int col) { var value … Read more
Matlab 7.3 file format is not extremely easy to work with h5py. It relies on HDF5 reference, cf. h5py documentation on references. >>> import h5py >>> f = h5py.File(‘test.mat’) >>> list(f.keys()) [‘#refs#’, ‘struArray’] >>> struArray = f[‘struArray’] >>> struArray[‘name’][0, 0] # this is the HDF5 reference <HDF5 object reference> >>> f[struArray[‘name’][0, 0]].value # this is … Read more
Get Mat.data and directly send to the socket, the data order is BGR BGR BGR…. On the receiving side assumes you know the size of image. After receiving just assign the received buffer(BGR BGR… array) to a Mat. Client:- Mat frame; frame = (frame.reshape(0,1)); // to make it continuous int imgSize = frame.total()*frame.elemSize(); // Send … Read more
I also was trying to do the same thing, because of need to combining image processed with two libraries. And what I’ve tried to do is to put byte[] in to Mat instead of RGB value. And it worked! So what I did was: 1.Converted BufferedImage to byte array with: byte[] pixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData(); … Read more
Code looks fine with one exception. Memory management. cv::Mat doesn’t work like QImage in this mater. Remember that QImage is using copy on write mechanism and shares memory for each copy. cv::Mat also shares memory but it doesn’t do copy on write (I’m also new with open cv (2 weeks) so I can’t explain yet … Read more
After MUCH trial and error, I managed to write a function to do it. here it is for anyone else who might want it: #include “stdafx.h” #include “opencv2/core/core.hpp” #include “opencv2/imgproc/imgproc.hpp” #include <opencv2/highgui/highgui.hpp> #include <Windows.h> #include <iostream> #include <string> using namespace std; using namespace cv; Mat hwnd2mat(HWND hwnd){ HDC hwindowDC,hwindowCompatibleDC; int height,width,srcheight,srcwidth; HBITMAP hbwindow; Mat src; … Read more
Are you ok with a 100x speedup? You should save and load your images in binary format. You can do that with the matwrite and matread function in the code below. I tested both loading from a FileStorage and the binary file, and for a smaller image with 250K rows, 192 columns, type CV_8UC1 I … Read more