How to imRotate with OpenCV, C++, and get the exact same result? - c++

Question

I tried everything available here related to this problem, but none gave me the exact same results, so I'd like to know if there exist one? and if so, how can I achieve it?
Let's talk about a simple example and hopefully find a way to get the same result in Matlab as well as in OpenCV:
Matlab:
test = [ 10 20 10 ; 20 10 10 ; 30 30 30]
im_rot = imrotate(double(test), -45, 'bilinear', 'crop');
Result:
im_rot =
11.7157 14.1421 11.7157
26.2132 10.0000 12.0711
17.5736 24.1421 5.8579
OpenCV:
double data[9]{ 10, 20, 10, 20, 10, 10, 30, 30, 30 };
Mat test = Mat(Size(3, 3), CV_64F, data);
What lines of code can get the exact same result as the one above?
Edit:
Tried the following:
void matlabImrotate(Mat& src, double angle, int interpolationMethod, Mat& dst)
{
// src: https://stackoverflow.com/questions/38715363/how-to-implement-imrotate-of-matlab-in-opencv
try
{
// Special Cases
if (fmod(angle, 360.0) == 0.0)
dst = src;
else {
Point2f center(src.cols / 2.0F, src.rows / 2.0F);
Mat rot = cv::getRotationMatrix2D(center, angle, 1.0);
cout << "center: " << center << endl;
// determine bounding rectangle
Rect bbox = RotatedRect(center, src.size(), angle).boundingRect();
// adjust transformation matrix
// cout << "bbox.size: " << bbox.size() << endl;
rot.at<double>(0, 2) += ((bbox.width ) / 2.0 - center.x );
rot.at<double>(1, 2) += ((bbox.height ) / 2.0 - center.y );
warpAffine(src, dst, rot, bbox.size(), interpolationMethod);
}
}
}
matlabImrotate(test, -45, INTER_LINEAR, res);
Result:
[0, 0, 0, 1.40625, 0, 0;
0, 0, 6.6796875, 11.69921875, 6.6796875, 0;
0, 8.7890625, 24.53125, 13.41796875, 14.53125, 2.9296875;
0, 2.8125, 23.4375, 20, 7.8125, 0.9375;
0, 0, 2.8125, 18.310546875, 1.875, 0;
0, 0, 0, 0.263671875, 0, 0]
Also tried:
void matlabImrotate2(Mat& src, double angle, int interpolationMethod, Mat& dst, int border=0)
{
// src: https://stackoverflow.com/questions/14870089/how-to-imrotate-with-opencv-2-4-3
Mat bordered_source;
int top, bottom, left, right;
top = bottom = left = right = border;
copyMakeBorder(src, bordered_source, top, bottom, left, right, BORDER_CONSTANT, cv::Scalar());
Point2f src_center(bordered_source.cols / 2.0F, bordered_source.rows / 2.0F);
Mat rot_mat = getRotationMatrix2D(src_center , angle, 1.0);
warpAffine(bordered_source, dst, rot_mat, bordered_source.size());
return true;
}
matlabImrotate2(test, -45, INTER_LINEAR, res);
Result:
[9.375, 17.28515625, 17.28515625;
23.4375, 21.09375, 11.09375;
2.8125, 23.4375, 15.625]