001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.image.feature.local.interest;
031
032import org.openimaj.image.FImage;
033import org.openimaj.image.processing.convolution.BasicDerivativeKernels;
034
035
036public class RidgeIPD extends AbstractStructureTensorIPD {
037        public RidgeIPD(float detectionScale, float integrationScale) {
038                super(detectionScale, integrationScale);
039        }
040        
041        @Override
042        public FImage createInterestPointMap() {
043                FImage lxx = l.process(BasicDerivativeKernels.DXX_KERNEL).multiplyInplace(detectionScale*detectionScale);
044                FImage lxy = l.process(BasicDerivativeKernels.DXY_KERNEL).multiplyInplace(detectionScale*detectionScale);
045                FImage lyy = l.process(BasicDerivativeKernels.DYY_KERNEL).multiplyInplace(detectionScale*detectionScale);
046                
047                FImage diff = lxx.subtractInplace(lyy);
048                
049                return  (diff.multiplyInplace(diff)).add(lxy.multiplyInplace(lxy).multiplyInplace(4f)).abs();
050        }
051
052        @Override
053        public RidgeIPD clone() {
054                return (RidgeIPD) super.clone();
055        }
056}