python-3.x - OpenCV 定位质心在 PiCam 上出现错误

Question

我有一个代码可以定位放置在相机前面的物体的质心。我在我的树莓派上运行了代码，我在项目中使用了 PiCam，cv2.moments()函数的输出对象的所有值都是 0。代码的相关部分是这样的：

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

camera = PiCamera()
camera.resolution = (640,480)
camera.framerate = 16
camera.rotation=180
rawCapture = PiRGBArray(camera, size=(640,480))

for f in camera.capture_continuous(rawCapture,format='bgr',use_video_port=True):  
    # ret, orig_frame = video.read()
    orig_frame = f.array
    hsv = cv2.cvtColor(orig_frame, cv2.COLOR_BGR2HSV)

    low_red = np.array([100, 100, 100])
    up_red = np.array([255, 255, 255])
    mask = cv2.inRange(hsv, low_red, up_red)
    edges = cv2.Canny(mask, 100, 200)
    bit = cv2.bitwise_or(orig_frame, orig_frame, mask= mask)

    contours, _ ,heirarchy= cv2.findContours(frame1, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)
    setpoint = 315
    stop1 = 250
    stop2 = 370



    for c in contours:

       M = cv2.moments(c)
       print(M) #OUTPUT HAS ALL VALUES 0
       # cX = int(M["m10"] / M["m00"]) 
       # cY = int(M["m01"] / M["m00"])

print(M)语句的输出是：

{'m20': 0.0, 'mu20': 0.0, 'nu30': 0.0, 'm03': 0.0, 'm10': 0.0, 'mu03': 0.0, 'nu02': 0.0, 'm11': 0.0, 'm21': 0.0, 'mu21': 0.0, 'mu02': 0.0, 'mu30': 0.0, 'm12': 0.0, 'm01': 0.0, 'm00': 0.0, 'nu20': 0.0, 'nu03': 0.0, 'nu21': 0.0, 'nu11': 0.0, 'm02': 0.0, 'nu12': 0.0, 'mu11': 0.0, 'mu12': 0.0, 'm30': 0.0}

如您所见，所有值均为 0

但是，如果我在使用其网络摄像头的笔记本电脑上运行相同的代码，则代码运行时不会出错，并且print(M)语句的输出是具有非零值的对象。

这是我本地机器上的代码：

import cv2
import numpy as np
video = cv2.VideoCapture(0)

def make_custom(x, y):
    video.set(3, x)
    video.set(4, y)

make_custom(800, 800) 
while True:
    ret, orig_frame = video.read()



    #frame = cv2.GaussianBlur(orig_frame, (5, 5), 0)
    hsv = cv2.cvtColor(orig_frame, cv2.COLOR_BGR2HSV)   
    low_red = np.array([100, 100, 100])
    up_red = np.array([255, 255, 255])
    mask = cv2.inRange(hsv, low_red, up_red)

    frame1 = cv2.GaussianBlur(mask, (5, 5), 1)
    edges = cv2.Canny(mask, 100, 200)
    bit = cv2.bitwise_or(orig_frame, orig_frame, mask= mask)

    contours, _ = cv2.findContours(frame1, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)       
    for c in contours:
   # calculate moments for each contour
       M = cv2.moments(c)
       print(M)

我在两台机器上都使用 Python 3.6

我做错了什么，我该如何纠正？

标签： python-3.xopencvraspberry-piraspberry-pi3webcam