Clone an image in cv2 python


Question

I'm new to opencv, here is a question, what is the python function which act the same as cv::clone() in cpp? I just try to get a rect by

    rectImg = img[10:20, 10:20]

but when I draw a line on it ,I find the line appear both on img and the rectImage,so , how can I get this done?

1
36
5/14/2013 12:05:07 AM

Accepted Answer

If you use cv2, correct method is to use .copy() method in Numpy. It will create a copy of the array you need. Otherwise it will produce only a view of that object.

eg:

In [1]: import numpy as np

In [2]: x = np.arange(10*10).reshape((10,10))

In [4]: y = x[3:7,3:7].copy()

In [6]: y[2,2] = 1000

In [8]: 1000 in x
Out[8]: False     # see, 1000 in y doesn't change values in x, parent array.
45
5/14/2013 5:01:20 AM

The first answer is correct but you say that you are using cv2 which inherently uses numpy arrays. So, to make a complete different copy of say "myImage":

newImage = myImage.copy()

The above is enough. No need to import numpy.


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