Write sequence of int with FileStorage in Python

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Hello,

I want to write a defaultConfig.xml file using the cv2.FileStorage Python bindings. For now I am using another lib to do the defaultConfig.xml generation because of a limit of the python bindings to write a right <camera_resolution> sequence of integers (defaultConfig.xml example).

I have a simple fix (bellow) and I would like to know if this is the best way to go.

The problem is with the <camera_resolution> integers sequence. I can't manage to write it using the actual python binding, as it is written as an opencv-matrix (Mat). Maybe the problem is that a Python binding must be create specifically for the sequence of integers, like it has be done for the sequence of Strings.

import cv2
fs = cv2.FileStorage('test.xml', cv2.FILE_STORAGE_WRITE)
fs.write("seq_int", [640, 480])
fs.release()

Produce the following problematic test.xml file:

<?xml version="1.0"?>
<opencv_storage>
<seq_int type_id="opencv-matrix">
  <rows>2</rows>
  <cols>1</cols>
  <dt>d</dt>
  <data>
    640. 480.</data></seq_int>
</opencv_storage>

In the last pre-4.0 released there are bindings for sequence of strings but not for sequence of integers. Line 202 in /modules/core/src/persistence_cpp.cpp

void FileStorage::write( const String& name, const std::vector<String>& val )
{
    *this << name << val;
}

I think I will propose as a PR (here is my actual fork) to add sequence of integers support:

void FileStorage::write( const String& name, const std::vector<int>& val )
{
    *this << name << val;
}

With this add, running test like in test_persistence.py

import cv2
fs = cv2.FileStorage('test.xml', cv2.FILE_STORAGE_WRITE)
fs.write("seq_int", [640, 480])
fs.release()

And I get the following good test.xml file:

<?xml version="1.0"?>
<opencv_storage>
<seq_int>
  640 480</seq_int>
</opencv_storage>

Do you thing it is the right way to go ?

I have read the PR discussion about vect strings support but could not find a definitive answer.

Thanks a lot if you take the time to read, and even more if you answer!