Hi, I'm rotating the 10x1 image by specifying center at 5,0:
[255, 255, 255, 255, 255, 255, 255, 255, 255, 255]
int size = 10;
Mat test = Mat::zeros(Size(size, 1), CV_8U);
line(test, Point(0, 0), Point(size, 0), Scalar(255));
Mat rot = getRotationMatrix2D(Point(test.cols/2, test.rows/2), 90, 1);
Mat dest;
warpAffine(test, dest, rot, Size(size, size));
imshow("Source", test);
imshow("Result", dest);
I assume that result will be the vertical line at center of 10x10 Mat, but it is shifted and cropped to the top:
[ 0, 0, 0, 0, 0, 255, 0, 0, 0, 0;
0, 0, 0, 0, 0, 255, 0, 0, 0, 0;
0, 0, 0, 0, 0, 255, 0, 0, 0, 0;
0, 0, 0, 0, 0, 255, 0, 0, 0, 0;
0, 0, 0, 0, 0, 255, 0, 0, 0, 0;
0, 0, 0, 0, 0, 255, 0, 0, 0, 0;
0, 0, 0, 0, 0, 0, 0, 0, 0, 0;
0, 0, 0, 0, 0, 0, 0, 0, 0, 0;
0, 0, 0, 0, 0, 0, 0, 0, 0, 0;
0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
I'm trying to understand why it happens?