開發環境：Python3.6.0 + OpenCV3.2.0

任務目標：攝像頭採集影象（例如：480*640），並對視訊流每一幀（灰度圖）特定矩形區域（480*30）畫素值進行行求和，得到一個480*1的陣列，用這480個數據繪製條形圖，即在逐幀採集視訊流並處理後“實時”顯示採集到的視訊，並“實時”更新條形圖。工作流程如下圖：

原始碼：

# -*- coding:utf-8 -*-
import cv2
import numpy as np

camera = cv2.VideoCapture(0) # 引數0表示第一個攝像頭
# camera = cv2.VideoCapture("test.avi") # 從檔案讀取視訊
 


# 判斷視訊是否開啟
if (camera.isOpened()):
    print 'Open'
else:
    print 'Fail to open!'

# # 測試用,檢視視訊size
# size = (int(camera.get(cv2.CAP_PROP_FRAME_WIDTH)),
#        int(camera.get(cv2.CAP_PROP_FRAME_HEIGHT)))
# print 'size:'+repr(size)

rectangleCols = 30
while True:
    grabbed, frame_lwpCV = camera.read
 
() # 逐幀採集視訊流
    if not grabbed:
        break
    gray_lwpCV = cv2.cvtColor(frame_lwpCV, cv2.COLOR_BGR2GRAY) # 轉灰度圖
    frame_data = np.array(gray_lwpCV)  # 每一幀迴圈存入陣列
    box_data = frame_data[:, 400:400+rectangleCols] # 取矩形目標區域
    pixel_sum = np.sum(box_data, axis=1) # 行求和q
    length = len(gray_lwpCV)
    x
 
 = range(length)
    emptyImage = np.zeros((rectangleCols*10, length*2, 3), np.uint8)
    for i in x:
        cv2.rectangle(emptyImage, (i*2, (rectangleCols-pixel_sum[i]/255)*10), ((i+1)*2, rectangleCols*10), (255, 0, 0), 1)
    emptyImage = cv2.resize(emptyImage, (320, 240))

    # 畫目標區域
    lwpCV_box = cv2.rectangle(frame_lwpCV, (400, 0), (430, length), (0, 255, 0), 2)
    cv2.imshow('lwpCVWindow', frame_lwpCV) # 顯示採集到的視訊流
    cv2.imshow('sum', emptyImage)  # 顯示畫出的條形圖
    key = cv2.waitKey(1) & 0xFF
    if key == ord('q'):
        break
camera.release()
cv2.destroyAllWindows()