search anaconda prompt open and run the command. > pip install opencv-python this single command help’s you to install opencv easily. you can take help from the video link below. video link
import cv2 import urllib import numpy as np stream = urllib.urlopen(‘http://localhost:8080/frame.mjpg’) bytes=”” while True: bytes += stream.read(1024) a = bytes.find(‘\xff\xd8’) b = bytes.find(‘\xff\xd9’) if a != -1 and b != -1: jpg = bytes[a:b+2] bytes = bytes[b+2:] i = cv2.imdecode(np.fromstring(jpg, dtype=np.uint8), cv2.CV_LOAD_IMAGE_COLOR) cv2.imshow(‘i’, i) if cv2.waitKey(1) == 27: exit(0) edit (explanation) I just saw that … Read more
You can use cv2.convertScaleAbs for this problem. See the Documentation. Check out the command terminal demo below : >>> img = np.empty((100,100,1),dtype = np.uint16) >>> image = cv2.cvtColor(img,cv2.COLOR_GRAY2BGR) >>> cvuint8 = cv2.convertScaleAbs(image) >>> cvuint8.dtype dtype(‘uint8’) Hope it helps!!!
I think ffmpeg should be used to play audio and SDL for video in this case. After opening the file with OpenCV and processing the frame, you can use OpenCV -> SDL to display it while retrieving the audio frames through ffmpeg and playing them with SDL. Here is a nice collection of ffmpeg/SDL tutorials! … Read more
In HSV space, the red color wraps around 180. So you need the H values to be both in [0,10] and [170, 180]. Try this: #include <opencv2\opencv.hpp> using namespace cv; int main() { Mat3b bgr = imread(“path_to_image”); Mat3b hsv; cvtColor(bgr, hsv, COLOR_BGR2HSV); Mat1b mask1, mask2; inRange(hsv, Scalar(0, 70, 50), Scalar(10, 255, 255), mask1); inRange(hsv, Scalar(170, … Read more
Perhaps cleaner: sudo update-alternatives –display cuda sudo update-alternatives –config cuda
Define the codec and create VideoWriter object like this fourcc = cv2.VideoWriter_fourcc(*’MPEG’) out = cv2.VideoWriter(‘output.avi’,fourcc, 20.0, (640,480))
BGR and RGB are not color spaces, they are just conventions for the order of the different color channels. cv2.cvtColor(img, cv2.COLOR_BGR2RGB) doesn’t do any computations (like a conversion to say HSV would), it just switches around the order. Any ordering would be valid – in reality, the three values (red, green and blue) are stacked … Read more
First of all, thank you for the clarity of the question. Q: Is it okay to use (multi)threading on application level with OpenCV? A: Yes it is totally ok to use multithreading on application level with OpenCV unless and until you are using functions which can take advantage of multithreading such as blurring, colour space … Read more