Dividing the frame into tiles

mp_tiled_frame.py

#!/usr/bin/python3
# Dividing the frame into tiles

import multiprocessing
import numpy as np
import cv2


class OpenCV_Multiprocessing:
    def __init__(self, features):
        self.font = cv2.FONT_HERSHEY_SIMPLEX
        self.detect = cv2.ORB_create(features)
        self.number_cpu = cv2.getNumberOfCPUs()
        self.input_q = multiprocessing.Queue(maxsize=self.number_cpu)
        self.output_q = multiprocessing.Queue(maxsize=self.number_cpu)
        self.pool = multiprocessing.Pool(self.number_cpu, self.worker, (self.input_q, self.output_q))

    def worker(self, input_q, output_q):
        while True:
            output_q.put(self.processing_ORB(input_q.get()))

    def processing_ORB(self, data_frame):        
        kp1, des1 = self.detect.detectAndCompute(data_frame[0], None)
        points = cv2.KeyPoint_convert(kp1)
        for xy in points:            
            cv2.drawMarker(data_frame[0], np.int32(xy), data_frame[2], 1, 10, 1, 8)
        cv2.putText(data_frame[0], 'Multiprocessing', (30, 30), self.font , 0.5, (255, 255, 255), 1)
        cv2.putText(data_frame[0], str(data_frame[1]), (30, 50), self.font , 0.5, (255, 255, 255), 1)
        return data_frame

    def __del__(self):
        print('Multiprocessing stop')
        self.pool.terminate()


if __name__ == '__main__':
    # logger = multiprocessing.log_to_stderr()
    # logger.setLevel(multiprocessing.SUBDEBUG)

    number_cpu = cv2.getNumberOfCPUs()

    mov = '/home/mo/GitHub/Video/traffic_01.mp4'
    cap = cv2.VideoCapture(mov)

    width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
    height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
    W = width//int(number_cpu*0.5)
    H = height//int(number_cpu*0.5)

    print('width:', width, 'height:', height)
    print('Number CPU:', number_cpu)

    cv2.namedWindow('frame', cv2.WINDOW_GUI_NORMAL | cv2.WINDOW_AUTOSIZE)
    # cv2.namedWindow('tile', cv2.WINDOW_GUI_NORMAL | cv2.WINDOW_AUTOSIZE)

    tiles = {}
    ocvmp = OpenCV_Multiprocessing(1000)
    rand_color = np.random.uniform(0, 255, size=(10, 3))

    while cap.isOpened():
        ret, frame = cap.read()
        count = 0
        if not ret:
            break        

        for i, y in enumerate(range(0, height, H)):
            for j, x in enumerate(range(0, width, W)):
                y1 = y + H
                x1 = x + W
                tiles[(i, j)] = (frame[y:y+H, x:x+W].copy(), (y, y1, x, x1), rand_color[count])
                cv2.rectangle(frame, (x, y), (x1, y1), (0, 255, 0))
                count += 1        

        for key, item in tiles.items():
            ocvmp.input_q.put((item[0], item[1], item[2]))

        key = cv2.waitKey(1)
        if key == ord('q') or key == 27:
            break
        elif key == ord('p'):
            cv2.waitKey(-1)

        for key in tiles:
            data_frame = ocvmp.output_q.get()
            coord = data_frame[1]
            frame[coord[0]:coord[1], coord[2]:coord[3]] = data_frame[0]
        
        cv2.imshow('frame', frame)
        # cv2.imshow('tile', tiles[(0, 1)][0])

    cap.release()
    cv2.destroyAllWindows()