search_red_part1.py

import numpy as np
import cv2

# open capturing device and check
cap = cv2.VideoCapture("DJI160.MOV")
# define color range - bottom and top of color space in GBR (reverse RGB)
boundaries = ([00, 00, 123], [88, 88 , 190])  

frames=0 #frame counter
# main loop - frame by frame proceesing
while(True):    
    # Capture next frame
    ret, frame = cap.read() 
    frame = frame + 1
    
    # create NumPy arrays from the color boundaries
    lower = np.array(boundaries[0], dtype = "uint8")
    upper = np.array(boundaries[1], dtype = "uint8")
    
    # create range color mas and apply
    mask = cv2.inRange(frame, lower, upper)
    filteredImg = cv2.bitwise_and(frame, frame, mask = mask)
    
    #count number of not zero pixels - must be grayscale, countNonZero don't work 
    grayImg = cv2.cvtColor(filteredImg, cv2.COLOR_BGR2GRAY)
    count = cv2.countNonZero(grayImg)
    
    print("Frame: %d\tRed pixels:%s" % (frame,count))
    
# end of main loop
# When everything done, release the capture and output
cap.release()