在python3下使用OpenCV 抓取攝像頭圖像並實時顯示3色直方圖
以下代碼為在Python3環境下利用OpenCV 抓取攝像頭的實時圖像, 通過OpenCV的 calHist函數計算直方圖, 並顯示在3個不同窗口中.
import cv2
import numpy as np
from matplotlib import pyplot as plt
import time
cap = cv2.VideoCapture(0)
for i in range(0, 19):
print(cap.get(i))
while(1):
ret, frame = cap.read()
# color = (‘b‘, ‘g‘, ‘r‘)
color = ((255,0,0), (0,255,0), (0,0,255))
for i, col in enumerate(color):
hist = cv2.calcHist([frame], [i], None, [256], [0, 256])
minVal, maxVal,minPos,maxPos = cv2.minMaxLoc(hist)
# print(minVal, maxVal,minPos,maxPos)
histImage = np.zeros([256,256,3], np.uint8)
for x in range(256):
cv2.line(histImage, (x,256), (x, 256-(hist[x]/maxVal)*250), col)
cv2.imshow("Hist{}".format(i), histImage)
cv2.imshow("Capture", frame)
# time.sleep(0.01)
key = cv2.waitKey(1)
if key & 0xff == ord(‘q‘) or key == 27:
print(frame.shape,ret)
break
cap.release()
cv2.destroyAllWindows()
在python3下使用OpenCV 抓取攝像頭圖像並實時顯示3色直方圖