在終端中運行 Python 程序時出錯

Question

我正在嘗試在終端中運行 Python 程序，但遇到以下錯誤

> pi@raspberrypi:~ $ python3 /home/pi/Cascades2/03_face_recognition.py
Traceback (most recent call last):
  File "/home/pi/Cascades2/03_face_recognition.py", line 15, in <module>
    recognizer.read('trainer/trainer.yml')
cv2.error: OpenCV(4.1.0) /home/pi/opencv-python/opencv_contrib/modules/face/src/facerec.cpp:61: error: (-2:Unspecified error) File can't be opened for reading! in function 'read'

當我與 Thonny 一起運行 Python 程序時，它運行良好。

有什么問題？

這是程序（03_face_recognition.py）代碼：

import cv2
import numpy as np
import os
import time
import datetime
import RPi.GPIO as GPIO

relay = 23
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(relay, GPIO.OUT)
GPIO.output(relay, 0)

recognizer = cv2.face.LBPHFaceRecognizer_create()
recognizer.read('trainer/trainer.yml')
cascadePath = "haarcascade_frontalface_default.xml"
faceCascade = cv2.CascadeClassifier(cascadePath);

font = cv2.FONT_HERSHEY_SIMPLEX

#initiate id counter
id = 0

# names related to ids: example ==> Jenifer: id=1,  etc
names = ['None', 'Jenifer', 'Luciola'] 

# Initialize and start realtime video capture
cam = cv2.VideoCapture('ipcamera')
frame_rate = 1
prev = 0

# Define min window size to be recognized as a face
minW = 0.1*cam.get(3)
minH = 0.1*cam.get(4)

while True:
    
    time_elapsed = time.time() - prev
    res, image = cam.read()

    if time_elapsed > 1./frame_rate:
        prev = time.time()

    ret, img =cam.read()

    gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)

    faces = faceCascade.detectMultiScale( 
        gray,
        scaleFactor = 1.2,
        minNeighbors = 5,
        minSize = (int(minW), int(minH)),
       )

    for(x,y,w,h) in faces:

        cv2.rectangle(img, (x,y), (x+w,y+h), (0,255,0), 2)

        id, confidence = recognizer.predict(gray[y:y+h,x:x+w])

        # Check if confidence is less than 100 ==> "0" is perfect match 
        if (confidence < 80):
            id = names[id]
            confidence = "  {0}%".format(round(100 - confidence))
            GPIO.output(relay, 1)
            print("Ouverture du portail", datetime.datetime.now(), id, confidence)
            time.sleep(1)
            GPIO.output(relay, 0)
            cam.release()
            time.sleep(30)
            cam = cv2.VideoCapture('ipcamera')
            
        else:
            GPIO.output(relay, 0)
        
        cv2.putText(img, str(id), (x+5,y-5), font, 1, (255,255,255), 2)
        cv2.putText(img, str(confidence), (x+5,y+h-5), font, 1, (255,255,0), 1)  
    
    cv2.imshow('camera',img)

    k = cv2.waitKey(10) & 0xff # Press 'ESC' for exiting video
    if k == 27:
        break
    
# Do a bit of cleanup
print("\n [INFO] Exiting Program and cleanup stuff")
cam.release()
cv2.destroyAllWindows()

預先感謝您的幫助！

Answer 1

這可能與當前工作目錄有關。

在您的錯誤中，您位於主目錄中。 如果您使用“thonny”運行程序，我想“thonny”將設置腳本的文件夾。

當您指定要打開的文件時，您使用的是相對路徑。 也許您可以改用絕對路徑。

Answer 2

這是一個簡單的解決方法，我不得不將trainer/trainer.yml替換為/home/pi/Cascades2/trainer/trainer.yml ，這是絕對路徑。