Hi there!
I have a CV_32FC2 image, and need to iterate over a line on that image (C++).
The LineIterator constructor does not report any issue, but from the pointer I can get only Vec2b -not Vec2f, as I need.
Yes it is possible. I've used it on a CV_32F to iterate through pixel values along a line.
You don't access pixels with lineIterator. LineIterator will let you know the current position within the line. Then you use that position to access the Mat in order to retrieve the data. If it is not a intensive process, you can use the Mat::at<cv::Vec2f>(lineIterator.pos()) to make it simple. If you are accessing tens of thousands of pixels in a cycle I suggest you find other way to access the Mat pixels, since the Mat::at method is not the fastest way, but those are separate issues.
Cheers.
Okay -that means this class does not provide any pixel access optimization. I just wanted to make sure, as there is the third argument of the constructor (connectivity), and the ptr member, and this suggest me that the class has its own pixel access methods. Thanks!
I think you can try like this
Mat im(50,50,CV_32FC2);
Point pt1(10,10),pt2(20,30);
for (int i = 0; i<im.rows; i++)
for (int j = 0; j<im.cols; j++)
im.at<Vec2f>(i,j) = Vec2f(i,j);
cv::LineIterator it(im, pt1, pt2, 8);
for (int i = 0; i < it.count; i++, ++it)
{
cv::Point p = it.pos();
Vec2f pixelValue = im.at<Vec2f>(p);
cout<<"pixel "<<p<<" = "<<pixelValue<<endl;
}
Asked: 2017-01-16 11:09:32 -0600
Seen: 450 times
Last updated: Jan 16 '17