Example Detect Describe Interface

BoofCV provides multiple ways to detect and describe interest points inside of images. The easiest high level interface to work with is DetectDescribePoint. It will detect and describe all interest points in the image at the same time. The alternative involves using separate interfaces for detection, orientation, and describing.

Example Code:

• ExampleDetectDescribe.java

Concepts:

• Interest point detection
• Local region descriptors

Relevant Applets:

• Interest Point Detector
• Describe Points

Related Examples

• Detecting Interest Points

Example Code

/**
 * {@link DetectDescribePoint} provides a single unified interface for detecting interest points inside of images
 * and describing the features. For some features (e.g. SIFT) it can be much faster than the alternative approach
 * where individual algorithms are used for feature detection, orientation estimation, and describe.  It also
 * simplifies the code.
 *
 * This example demonstrates how to create instances, but the {@link ExampleAssociatePoints} demonstrates how
 * to use the interface.
 *
 * @author Peter Abeles
 */
public class ExampleDetectDescribe {

	/**
	 * For some features, there are pre-made implementations of DetectDescribePoint.  This has only been done
	 * in situations where there was a performance advantage or that it was a very common combination.
	 */
	public static <T extends ImageSingleBand, TD extends TupleDesc>
	DetectDescribePoint<T, TD> createFromPremade( Class<T> imageType ) {
		return (DetectDescribePoint)FactoryDetectDescribe.surfStable(
				new ConfigFastHessian(1, 2, 200, 1, 9, 4, 4), null,null, ImageFloat32.class);
		// note that SIFT only supports ImageFloat32
//		if( imageType == ImageFloat32.class )
//			return (DetectDescribePoint)FactoryDetectDescribe.sift(null,new ConfigSiftDetector(2,0,200,5),null,null);
//		else
//			throw new RuntimeException("Unsupported image type");
	}

	/**
	 * Any arbitrary implementation of InterestPointDetector, OrientationImage, DescribeRegionPoint
	 * can be combined into DetectDescribePoint.  The syntax is more complex, but the end result is more flexible.
	 * This should only be done if there isn't a pre-made DetectDescribePoint.
	 */
	public static <T extends ImageSingleBand, TD extends TupleDesc>
	DetectDescribePoint<T, TD> createFromComponents( Class<T> imageType ) {
		// create a corner detector
		Class derivType = GImageDerivativeOps.getDerivativeType(imageType);
		GeneralFeatureDetector corner = FactoryDetectPoint.createShiTomasi(new ConfigGeneralDetector(1000,5,1), false, derivType);
		InterestPointDetector detector = FactoryInterestPoint.wrapPoint(corner, 1, imageType, derivType);

		// describe points using BRIEF
		DescribeRegionPoint describe = FactoryDescribeRegionPoint.brief(new ConfigBrief(true), imageType);

		// Combine together.
		// NOTE: orientation will not be estimated
		return FactoryDetectDescribe.fuseTogether(detector, null, describe);
	}

	public static void main( String args[] ) {

		Class imageType = ImageFloat32.class;

		DetectDescribePoint detDesc = createFromPremade(imageType);
//		DetectDescribePoint detDesc = createFromComponents(imageType);

		// Might as well have this example do something useful, like associate two images
		ScoreAssociation scorer = FactoryAssociation.defaultScore(detDesc.getDescriptionType());
		AssociateDescription associate = FactoryAssociation.greedy(scorer, Double.MAX_VALUE, true);

		// load and match images
		ExampleAssociatePoints app = new ExampleAssociatePoints(detDesc,associate,imageType);

		BufferedImage imageA = UtilImageIO.loadImage("../data/evaluation/stitch/kayak_01.jpg");
		BufferedImage imageB = UtilImageIO.loadImage("../data/evaluation/stitch/kayak_03.jpg");

		app.associate(imageA,imageB);
	}
}