/*
* @(#)ImageDominanceScanner.java 30/10/2004
*
* Copyright (c) 2004, 2005 jASEN.org
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. 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.
*
* 3. The names of the authors may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 4. Any modification or additions to the software must be contributed back
* to the project.
*
* 5. Any investigation or reverse engineering of source code or binary to
* enable emails to bypass the filters, and hence inflict spam and or viruses
* onto users who use or do not use jASEN could subject the perpetrator to
* criminal and or civil liability.
*
* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED 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 JASEN.ORG,
* OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
package org.jasen.plugins;
import java.util.Properties;
import javax.mail.internet.MimeMessage;
import org.jasen.core.ProbabilityTestResult;
import org.jasen.core.StandardParserData;
import org.jasen.core.engine.Jasen;
import org.jasen.error.JasenException;
import org.jasen.interfaces.JasenMessage;
import org.jasen.interfaces.JasenPlugin;
import org.jasen.interfaces.JasenTestResult;
import org.jasen.interfaces.ParserData;
import org.jasen.interfaces.ReceivedHeaderParser;
/**
* <P>
* Tests for high ratios of images vs text.
* </P>
*
* @author Jason Polites
*/
public class ImageDominanceScanner implements JasenPlugin
{
private float lowProb = 0.4f;
private float highProb = 0.9f;
private float ratio = 1.0f;
private int wordSize = 12;
/**
*
*/
public ImageDominanceScanner() {
super ();
}
/*
* (non-Javadoc)
*
* @see org.jasen.interfaces.JasenPlugin#init(java.util.Properties)
*/
public void init(Properties properties) throws JasenException {
if (properties != null)
{
String strHi = properties.getProperty ("max");
String strLo = properties.getProperty ("min");
String strRatio = properties.getProperty ("ratio");
if (strHi != null)
highProb = Float.parseFloat (strHi);
if (strLo != null)
lowProb = Float.parseFloat (strLo);
if (strRatio != null)
ratio = Float.parseFloat (strRatio);
}
}
/*
* (non-Javadoc)
* @see org.jasen.interfaces.JasenPlugin#destroy()
*/
public void destroy() throws JasenException {}
/*
* (non-Javadoc)
* @see org.jasen.interfaces.JasenPlugin#test(org.jasen.core.Jasen, javax.mail.internet.MimeMessage, org.jasen.interfaces.JasenMessage, org.jasen.interfaces.ParserData, org.jasen.interfaces.ReceivedHeaderParser)
*/
public JasenTestResult test(Jasen engine, MimeMessage rawMessage, JasenMessage parsedMessage, ParserData data, ReceivedHeaderParser parser) throws JasenException {
ProbabilityTestResult result = new ProbabilityTestResult ();
// Num words...(only look in html)
int numHtmlWords = 0;
int numImages = 0;
// For performance reasons, we aren't going to bother splitting, removing stop words etc
// Instead, we simply assume that the total chars represents a number of average sized
// words
if(data.getHtmlAsText() != null) {
numHtmlWords = data.getHtmlAsText().length() / wordSize; // average word size
}
if(data instanceof StandardParserData) {
numImages = ((StandardParserData)data).getImageCount();
}
if(numImages == 0) {
result.setProbability(lowProb);
}
else if (numHtmlWords == 0) {
result.setProbability(highProb);
}
else {
float prob = (((float)numImages / (float)numHtmlWords));
if(prob >= ratio) {
result.setProbability(highProb);
}
else if(prob <= lowProb) {
result.setProbability(lowProb);
}
else {
result.setProbability(prob);
}
}
return result;
}
}