OpenCV cv2.imwrite（）在循环中无法将图像保存到文件夹中

Question

我通过网络摄像头识别人脸，我有一些图像的数据集。 当我尝试用静态名称保存图像时，它会保存该图像，但当我尝试在循环中保存图像时，它不会保存

文件夹目录

1. imagesAttendance[文件夹]

2. imageResult[文件夹]

3. start.py

结束文件夹目录

start.py

import cv2
import numpy as np
import face_recognition
import os
from datetime import datetime
from PIL import Image
# from PIL import ImageGrab
 
path = 'ImagesAttendance'
saveResults = 'ImageResult'
images = []
classNames = []
myList = os.listdir(path)
print(myList)
for cl in myList:
    curImg = cv2.imread(f'{path}/{cl}')
    images.append(curImg)
    classNames.append(os.path.splitext(cl)[0])
print(classNames)
 
def findEncodings(images):
    encodeList = []
    for img in images:
        img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
        encode = face_recognition.face_encodings(img)[0]
        encodeList.append(encode)
    return encodeList
 
def markAttendance(name, img):
    with open('Attendance.csv','r+') as f:
        myDataList = f.readlines()
        nameList = []
        for line in myDataList:
            entry = line.split(',')
            nameList.append(entry[0])
        
        now = datetime.now()
        dtString = now.strftime('%H:%M:%S')
        f.writelines(f'\n{name},{dtString}')
        ## saving image into database
        im = Image.fromarray(img)
        datee = str(now)
        cv2.imwrite('ImageResult/Image'+'anyname'+'.jpg', img)### this is working
        # cv2.imwrite('ImageResult/Image'+datee+'.jpg', img)### this is not working
    
 
#### FOR CAPTURING SCREEN RATHER THAN WEBCAM
# def captureScreen(bbox=(300,300,690+300,530+300)):
#     capScr = np.array(ImageGrab.grab(bbox))
#     capScr = cv2.cvtColor(capScr, cv2.COLOR_RGB2BGR)
#     return capScr
 
encodeListKnown = findEncodings(images)
print('Encoding Complete')
 
cap = cv2.VideoCapture(0)
 
while True:
    success, img = cap.read()
    #img = captureScreen()
    imgS = cv2.resize(img,(0,0),None,0.25,0.25)
    imgS = cv2.cvtColor(imgS, cv2.COLOR_BGR2RGB)
 
    facesCurFrame = face_recognition.face_locations(imgS)
    encodesCurFrame = face_recognition.face_encodings(imgS,facesCurFrame)
    
    for encodeFace,faceLoc in zip(encodesCurFrame,facesCurFrame):
        matches = face_recognition.compare_faces(encodeListKnown,encodeFace)
        faceDis = face_recognition.face_distance(encodeListKnown,encodeFace)
        #print(faceDis)
        matchIndex = np.argmin(faceDis)
 
        if matches[matchIndex]:
            name = classNames[matchIndex].upper()
            #print(name)
            y1,x2,y2,x1 = faceLoc
            y1, x2, y2, x1 = y1*4,x2*4,y2*4,x1*4
            cv2.rectangle(img,(x1,y1),(x2,y2),(0,255,0),2)
            cv2.rectangle(img,(x1,y2-35),(x2,y2),(0,255,0),cv2.FILLED)
            cv2.putText(img,name,(x1+6,y2-6),cv2.FONT_HERSHEY_COMPLEX,1,(255,255,255),2)
            markAttendance(name, img)

            
            
    cv2.imshow('Webcam',img)
    cv2.waitKey(1)

使用saveMatch（）函数

def markAttendance(name, img):
    with open('Attendance.csv','r+') as f:
        ...
        cv2.imwrite('ImageResult/Image'+'anyname'+'.jpg', img)### this is working

saveMatch（）函数不起作用

def markAttendance(name, img):
    with open('Attendance.csv','r+') as f:
        ...
                cv2.imwrite('ImageResult/Image'+datee+'.jpg', img)### this is not working

我想在ImageResult目录中保存所有检测到的图像

Answer 1

重要提示：

在Macbook和Linux中，saveMatch（）函数将与Date一起使用，因为操作系统允许您将文件保存为:等字符

问题：

在Windows中，:是文件名的无效字符

如果您试图在Windows中保存具有invaild字符的文件，您可以在下面的代码中看到使用函数str（datetime.now（）获得的结果

date = datetime.now()
print(str(date))
>>>>> 2021-09-24 00:23:29.720260

您可以在链接中阅读有关Comparison of filename limitations的更多信息

解决方案：

您可以使用下一种方法修复它：

def markAttendance(name, img):
    with open('Attendance.csv','r+') as f:
        ...
        cv2.imwrite('ImageResult/Image'+str(datee.strftime('%Y-%m-%d-%H-%M-%S'))'+'.jpg, img)

您可以找到有关datetime包here的strftime（）函数的更多信息