我有一个简单的项目与Raspi 4与摄像头，该项目是类似的汽车的反向摄像头，但没有传感器.这里我的代码：

import time
import cv2
import numpy as np
from picamera.array import PiRGBArray
from picamera import PiCamera

camera = PiCamera()
camera.resolution = (1080, 720) # camera resolution 
camera.framerate = 25
rawCapture = PiRGBArray(camera, size=(1080,720))
kernel = np.ones((2,2),np.uint8)
time.sleep(0.1)
for still in camera.capture_continuous(rawCapture, format="bgr", use_video_port=True):
    
    image = still.array
    #create a detection area
    widthAlert = np.size(image, 1) #get width of image
    heightAlert = np.size(image, 0) #get height of image
    yAlert = (heightAlert/2) + 100 #determine y coordinates for area
    cv2.line(image, (0,yAlert), (widthAlert,yAlert),(0,0,255),2) #draw a line to show area
    
    lower = [1, 0, 20]
    upper = [60, 40, 200]
    lower = np.array(lower, dtype="uint8")
    upper = np.array(upper, dtype="uint8")
    #use the color range to create a mask for the image and apply it to the image
    mask = cv2.inRange(image, lower, upper)
    output = cv2.bitwise_and(image, image, mask=mask)
    
    dilation = cv2.dilate(mask, kernel, iterations = 3)
    closing = cv2.morphologyEx(dilation, cv2.MORPH_GRADIENT, kernel)
    closing = cv2.morphologyEx(dilation, cv2.MORPH_CLOSE, kernel)
    edge = cv2.Canny(closing, 175, 175)
    
    contours, hierarchy = cv2.findContours(closing, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
    
    threshold_area = 400
    centres = []
    
    if len(contours) !=0:
        
        for x in contours:
            #find the area of each contour
            area = cv2.contourArea(x)
            #find the center of each contour
            moments = cv2.moments(x)
            #weed out the contours that are less than our threshold
            if area > threshold_area:
                
                (x,y,w,h) = cv2.boundingRect(x)
                
                centerX = (x+x+w)/2
                centerY = (y+y+h)/2
                
                cv2.circle(image,(centerX, centerY), 7, (255, 255, 255), -1)
                
                if ((y+h) > yAlert):
                    cv2.putText(image, "ALERT!", (centerX -20, centerY -20), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (255,255,255),2)
    
    cv2.imshow("Display", image)
    
    rawCapture.truncate(0)
    
    key = cv2.waitKey(1) & 0xFF
    if key == ord("q"):
        break

我得到的错误是：

image = still.array
    #create a detection area
    widthAlert = np.size(image, 1) #get width of image
    heightAlert = np.size(image, 0) #get height of image
    yAlert = (heightAlert/2) + 100 #determine y coordinates for area
    cv2.line(image, (0,yAlert), (widthAlert,yAlert),(0,0,255),2) #draw a line to show area

问题是：回溯（最近的呼叫排在最后）：文件“/home/pi/Desktop/object_detector.py”，第20行，位于
cv2.line（image，（0，yAlert），（widthAlert，yAlert），（0，0，255），2）#绘制一条线以显示区域
错误代码：OpenCV（4.5.3）错误代码：函数'line'中的（-5：错误的参数）
重载解析失败：

• 无法分析“pt 1”。索引为1的序列项的类型错误
• 无法分析“pt 1”。索引为1的序列项的类型错误