I am confused by the following pseudocode:
cv::Mat a(row,col,datatype);
/*
codes fill data in a
*/
cv::Mat b(row,col,datatype);//allocate memory for b, b has same size with a
for(int i=0; i< a.rows; i++)
{
b.row(i) = a.row(i);//for each line
}
does b shares the same date with a?
this is a quite common pitfall.
Mat r = b.row(i);
makes a new Mat header, with data pointing to row i of the original Mat. so far, so good. but it's a copy !.
assigning another Mat to it will NOT change the original Mat ! so:
b.row(i) = a.row(i);
does not do anything (again, since you assign it to a copy)
a.row(i).copyTo(b.row(i));
would have done, what you probably expected. but since you try to do that for every row anyway, rather use a plain:
a.copyTo(b);
or even (same):
b = a.clone();
Asked: 2018-05-10 03:39:32 -0600
Seen: 2,082 times
Last updated: May 10 '18