I’ve solved my own problem. Line iterator seems to be unavailable in the cv2 library. Therefore, I made my own line iterator. No loops are used, so it should be pretty fast. Here is the code if anybody needs it: def createLineIterator(P1, P2, img): “”” Produces and array that consists of the coordinates and intensities … Read more
There are three different things going on here. Reduce the number of colors of an image Get the different colors of an image Get the color name Reduce the number of colors There are many techniques to reduce the number of colors. Here you can see how to use color quantization and kmeans. Another approach … Read more
A lot of things changed from OpenCV 2.4 to OpenCV 3.0. Among others, the machine learning module, which isn’t backward compatible. This is the OpenCV tutorial code for the SVM, update for OpenCV 3.0: #include <opencv2/core.hpp> #include <opencv2/imgproc.hpp> #include “opencv2/imgcodecs.hpp” #include <opencv2/highgui.hpp> #include <opencv2/ml.hpp> using namespace cv; using namespace cv::ml; int main(int, char**) { // … Read more
Your second approach is correct, but you have source and destination of different types in cvtColor, and that causes the error. Be sure to have both hsv and bgr of the same type, CV_32F here: #include <opencv2/opencv.hpp> #include <iostream> int main() { cv::Mat3f hsv(cv::Vec3f(0.7, 0.7, 0.8)); std::cout << “HSV: ” << hsv << std::endl; cv::Mat3f … Read more
So you have a problem unrelated to your question. However, you can achieve your goal using only OpenCV highgui facilites: #include <opencv2\opencv.hpp> #include <iostream> using namespace std; using namespace cv; vector<Rect> rects; bool bDraw; Rect r; Point base; Mat3b img; Mat3b layer; Mat3b working; void CallBackFunc(int event, int x, int y, int flags, void* userdata) … Read more
I have achieved this by using the following snippet. import cv2 file_name = “grab.png” src = cv2.imread(file_name, 1) tmp = cv2.cvtColor(src, cv2.COLOR_BGR2GRAY) _,alpha = cv2.threshold(tmp,0,255,cv2.THRESH_BINARY) b, g, r = cv2.split(src) rgba = [b,g,r, alpha] dst = cv2.merge(rgba,4) cv2.imwrite(“test.png”, dst)
Here the steps to use OpenCV 3.0.0 with precompiled libs, for a C++ project that links OpenCV statically, in Windows (tested with Windows 8.1) and Visual Studio (tested with Visual Studio 2013) to run this program: #include <opencv2\opencv.hpp> using namespace cv; int main() { Mat3b img = imread(“path_to_image”); imshow(“img”, img); waitKey(); return 0; } Download … Read more
This error message error: (-215)size.width>0 && size.height>0 in function imshow simply means that imshow() is not getting video frame from input-device. You can try using cap = cv2.VideoCapture(1) instead of cap = cv2.VideoCapture(0) & see if the problem still persists.
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
As @neil said there is no simple answer. But I would like to tell you how I would approach this non-trivial task. Get as much data as possible. This is critical to get this task done. If you have small amount of data, higher the chance you would choose parameters that work on the data … Read more