Hi, I'm sorry to ask but I'm new to OpenCV for Android, and I've tried to change this [code on the last answer ](http://answers.opencv.org/question/93317/orb-keypoints-distribution-over-an-image/#93395)to Java. The questions are:
1. I don't understand `sort` function. Is that from library? If it's not how should I make it?
2. Is the `numeric_limits` I set myself? If yes, what number should I set it to?
3. `Core.norm( keypoints.get(i).pt - keypoints.get(j).pt )` Java can't substract Point with Point. I've tried `Point temp = new Point(keypoints.get(i).pt.x - keypoints.get(j).pt.x, keypoints.get(i).pt.y - keypoints.get(j).pt.y)` but the `Core.norm` need Mat parameter.
4. `swap` function on the bottom?
The code that I change
public void adaptiveNonMaximalSuppresion( List keypoints,
const int numToKeep )
{
if( keypoints.size() < numToKeep ) { return; }
//
// Sort by response
//
//sort( keypoints.begin(), keypoints.end(),
//[&]( const cv::KeyPoint& lhs, const cv::KeyPoint& rhs )
//{
// return lhs.response > rhs.response;
//} );
List anmsPts = new ArrayList();
List radii = new ArrayList();
//radii.resize( keypoints.size() );
List radiiSorted = new ArrayList();
//radiiSorted.resize( keypoints.size() );
Float robustCoeff = 1.11f; // see paper
for( int i = 0; i < keypoints.size(); ++i )
{
Float response = keypoints.get(i).response * robustCoeff;
Double radius = numeric_limits::max();
for( int j = 0; j < i && keypoints[j].response > response; ++j )
{
radius = Math.min( radius, Core.norm( keypoints.get(i).pt - keypoints.get(j).pt ) );
}
radii.set(i,radius);
radiiSorted.set(i,radius);
}
//std::sort( radiiSorted.begin(), radiiSorted.end(),
//[&]( const double& lhs, const double& rhs )
//{
// return lhs > rhs;
//} );
Double decisionRadius = radiiSorted.get(numToKeep);
for( int i = 0; i < radii.size(); ++i )
{
if( radii.get(i) >= decisionRadius )
{
anmsPts.add( keypoints.get(i) );
}
}
anmsPts.swap( keypoints );
}
↧