在 Django views.py 中使用 cv2.imread() 读取图像时出错

Question

I am trying to apply image processing on an image which i'm loading through cv2.imread() in Django's views.py file, but i'm getting an AttributeError everytime.

Following is the hierarchy

views.py through which i'm trying to read temp321.jpg :

def process_image(request):
    url = "static/images/temp321.jpg"
    a = cv2.imread(url)
    r, c = a.shape

Error which i'm getting:

What am i doing wrong?

Answer 1

This error indicates that a is None. With a being the result of the call to cv2.imread

If the image cannot be read (because of missing file, improper permissions, unsupported or invalid format), the function returns an empty matrix

This is from the cv2 c documentation. This translates to None in python. So the problem essentially is that your file is not being read.

The solution: If you have setup the PROJECT_ROOT variable properly in your settings.py file

os.path.join(PROJECT_ROOT, "static/images/temp321.jpg")

If you don't have PROJECT_ROOT setup, add to settings.py

PROJECT_ROOT = os.path.abspath(os.path.dirname(__file__))

Note that you may still have trouble if you are doing this in production because the webserver may not be allowed to read from that directory. In that case you will need to change file system permissions

Answer 2

以下代码对我有用

img_path = os.path.join(settings.STATIC_ROOT,"directory/image.jpg")