OpenCV 将文本放在原始文件上

Question

我需要帮助在网络摄像机拍摄的图像上加上时间戳，我制作了一个将图像保存为本地文件的代码版本，然后用 opencv 在上面写入，现在我想在上面写入它之前没有保存过，但我被卡住了。这是代码：

import requests
import time
import shutil
import os
from requests.auth import HTTPBasicAuth
import cv2
from datetime import datetime
from datetime import date
import numpy as np


url = 'http://192.168.0.138/image.jpg?cidx=366981845'


user = '****'
psw = '****'

path = 'ipCameraScreen.png'



font = cv2.FONT_HERSHEY_SIMPLEX
position = (20, 30)
color = (255, 255, 255)
font_size = 0.5
font_stroke = 1


while True:

    response = requests.get(url, auth=HTTPBasicAuth(user, psw), stream = True)
    resp_raw = response.raw

    if response.status_code == 200:

        # DEFINE TIMESTAMP
        current_date = str(date.today())
        current_time = datetime.now().strftime("%H:%M:%S")
        timestamp = (current_date + " | " + current_time)

        with open(path, 'wb') as out_file:
            shutil.copyfileobj(response.raw, out_file)
            img = np.asarray(bytearray(resp_raw.read()), dtype="uint8")
            img = cv2.imdecode(img, cv2.IMREAD_COLOR)
            cv2.putText(img, timestamp, position, font, font_size, color, font_stroke)
            cv2.imwrite(path, img)
        print("Screen saved, path:", path)
        time.sleep(3)
    else:
        print("Connection failed")


    time.sleep(3)

    if os.path.exists(path):
            os.remove(path)
            print("image removed")
            time.sleep(2)

输出为：

cv2.error: OpenCV(4.5.2) C:\Users\runneradmin\AppData\Local\Temp\pip-req-build-m8us58q4\opencv\modules\imgcodecs\src\loadsave.cpp:736: error: (-215:Assertion failed) !buf.empty() in function 'cv::imdecode_'

请帮助我，很抱歉简单的英语

Answer 1

您的错误指出，当您尝试使用 imdecode() 将数组解码为 img 时，缓冲区为空。

这意味着在上一行中：

img = np.asarray(bytearray(resp_raw.read()), dtype="uint8")

resp_raw.read() 给你一个空数组。

我会分析您使用 Postman 等工具执行的 GET 请求，或者只是尝试打印 resp_raw 的内容，因为它似乎 return 不是您的图像。

Answer 2

我解决了，我只是重新定义了 resp_raw 的请求，我这样做了：

response = requests.get(url, auth=HTTPBasicAuth(user, psw), stream = True)
resp_raw = requests.get(url, auth=HTTPBasicAuth(user, psw), stream = True).raw

而不是这个：

response = requests.get(url, auth=HTTPBasicAuth(user, psw), stream = True)
resp_raw = response.raw

OpenCV 将文本放在原始文件上

OpenCV put text on raw files

python

image

opencv

raw