All Downloads are FREE. Search and download functionalities are using the official Maven repository.

boofcv.alg.transform.pyramid.PyramidDiscreteSampleBlur Maven / Gradle / Ivy

Go to download

BoofCV is an open source Java library for real-time computer vision and robotics applications.

There is a newer version: 0.26
Show newest version
/*
 * Copyright (c) 2011-2013, Peter Abeles. All Rights Reserved.
 *
 * This file is part of BoofCV (http://boofcv.org).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package boofcv.alg.transform.pyramid;

import boofcv.abst.filter.convolve.GenericConvolveDown;
import boofcv.core.image.border.BorderType;
import boofcv.factory.filter.convolve.FactoryConvolveDown;
import boofcv.struct.convolve.Kernel1D;
import boofcv.struct.image.ImageSingleBand;
import boofcv.struct.pyramid.PyramidDiscrete;

/**
 * 

* Convolves a re-normalizable blur kernel across the image before down sampling. This is useful for creating * a Gaussian pyramid as well as other standard pyramids. *

* *

* NOTE: This pyramid cannot be configured such that blur will be applied to the input image. It can be done by * the user before the image is passed in. *

* *

* NOTE: This blur magnitude is constant for each level in the pyramid. In general it is desirable to * have it dependent on each level's scale factor. *

* * @author Peter Abeles */ @SuppressWarnings({"unchecked"}) public class PyramidDiscreteSampleBlur extends PyramidDiscrete { // stores the results from the first convolution private T temp; GenericConvolveDown horizontal; GenericConvolveDown vertical; // amount of blur applied to each layer double sigmas[]; /** * * @param kernel A blur kernel * @param sigma The effective amount of Gaussian blur the kernel applies * @param imageType Type of image processed * @param saveOriginalReference If a reference to the full resolution image should be saved instead of copied. * Set to false if you don't know what you are doing. * @param scaleFactors Scale factor for each layer in the pyramid relative to the input layer */ public PyramidDiscreteSampleBlur(Kernel1D kernel, double sigma, Class imageType, boolean saveOriginalReference, int... scaleFactors) { super(imageType,saveOriginalReference,scaleFactors); horizontal = FactoryConvolveDown.convolve(kernel,imageType,imageType, BorderType.NORMALIZED,true,1); vertical = FactoryConvolveDown.convolve(kernel,imageType,imageType, BorderType.NORMALIZED,false,1); sigmas = new double[ scaleFactors.length ]; sigmas[0] = 0; for( int i = 1; i < sigmas.length; i++ ) { // blur in previous layer double prev = sigmas[i-1]; // the effective amount of blur applied to previous layer while being down sampled double applied = sigma*scaleFactors[i-1]; // The amount of blur which has been applied to this layer sigmas[i] = Math.sqrt(prev*prev + applied*applied); } } @Override public void process(T input) { super.initialize(input.width,input.height); if( temp == null ) { // declare it to be the latest image that it might need to be, resize below temp = (T)input._createNew(1,1); } if (scale[0] == 1) { if (isSaveOriginalReference()) { setFirstLayer(input); } else { getLayer(0).setTo(input); } } else { int skip = scale[0]; horizontal.setSkip(skip); vertical.setSkip(skip); temp.reshape(input.width/skip,input.height); horizontal.process(input,temp); vertical.process(temp,getLayer(0)); } for (int index = 1; index < getNumLayers(); index++) { int skip = scale[index]/scale[index-1]; T prev = getLayer(index-1); temp.reshape(prev.width/skip,prev.height); horizontal.setSkip(skip); vertical.setSkip(skip); horizontal.process(prev,temp); vertical.process(temp,getLayer(index)); } } /** * There is no offset since a symmetric kernel is applied starting at pixel (0,0) * * @param layer Layer in the pyramid * @return offset */ @Override public double getSampleOffset(int layer) { return 0; } @Override public double getSigma(int layer) { return sigmas[layer]; } }




© 2015 - 2024 Weber Informatics LLC | Privacy Policy