org.openimaj.image.processing.convolution.FSobel Maven / Gradle / Ivy
/**
* Copyright (c) 2011, The University of Southampton and the individual contributors.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of the University of Southampton nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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*/
package org.openimaj.image.processing.convolution;
import org.openimaj.image.FImage;
import org.openimaj.image.analyser.ImageAnalyser;
/**
* Helper {@link ImageAnalyser} that computes the X and Y image gradients using
* Sobel filters. Optionally, the input image can be blurred first using a
* Gaussian.
*
* @author Jonathon Hare ([email protected])
*/
public class FSobel implements ImageAnalyser {
private float sigma;
/**
* The X gradients
*/
public FImage dx;
/**
* The Y gradients
*/
public FImage dy;
/**
* Construct with no Gaussian blurring
*/
public FSobel() {
this(0);
}
/**
* Construct with an initial Gaussian blurring of the given standard
* deviation.
*
* @param sigma
* the standard deviation of the Gaussian blur
*/
public FSobel(float sigma) {
this.sigma = sigma;
}
@Override
public void analyseImage(FImage image) {
final FImage tmp = sigma == 0 ? image : image.process(new FGaussianConvolve(sigma));
dx = tmp.process(new FSobelX());
dy = tmp.process(new FSobelY());
}
}