/*
* eXist Image Module Extension CropFunction
* Copyright (C) 2011 Christian Wittern
*
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id: $
*/
package org.exist.xquery.modules.image;
import org.apache.log4j.Logger;
import org.exist.external.org.apache.commons.io.output.ByteArrayOutputStream;
import java.awt.Toolkit;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.awt.image.CropImageFilter;
import java.awt.image.FilteredImageSource;
import javax.imageio.ImageIO;
import org.exist.dom.QName;
import org.exist.xquery.BasicFunction;
import org.exist.xquery.Cardinality;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.Base64Binary;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.IntegerValue;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
/**
* eXist Image Module Extension CropFunction
*
* Crops an Image
*
* Written by Christian Wittern, based on the scale function by Adam and Loren, with help from Rafael Troilo
* @author Adam Retter <adam@exist-db.org>
* @author Loren Cahlander
* @author Christian Wittern
* @serial 2011-03-05
* @version 1.0
*
* @see org.exist.xquery.BasicFunction#BasicFunction(org.exist.xquery.XQueryContext, org.exist.xquery.FunctionSignature)
*/
public class CropFunction extends BasicFunction {
private static final Logger logger = Logger.getLogger(CropFunction.class);
private final static int MAXHEIGHT = 100;
private final static int MAXWIDTH = 100;
public final static FunctionSignature signature = new FunctionSignature(
new QName("crop", ImageModule.NAMESPACE_URI, ImageModule.PREFIX),
"Crop the image $image to a specified dimension. If no dimensions are specified, then the default values are 'y1 = 0', 'x1 = 0', 'x2 = 100' and 'y2 = 100'.",
new SequenceType[] {
new FunctionParameterSequenceType("image", Type.BASE64_BINARY, Cardinality.EXACTLY_ONE, "The image data"),
new FunctionParameterSequenceType("dimension", Type.INTEGER, Cardinality.ZERO_OR_MORE, "The maximum dimension of the cropd image. expressed in pixels (x1, y1, x2, y2). If empty, then the default values are are 'y1 = 0', 'x1 = 0', 'x2 = 100' and 'y2 = 100'."),
new FunctionParameterSequenceType("mimeType", Type.STRING, Cardinality.EXACTLY_ONE, "The mime-type of the image")
},
new FunctionReturnSequenceType(Type.BASE64_BINARY, Cardinality.ZERO_OR_ONE, "the cropd image or an empty sequence if $image is invalid")
);
/**
* CropFunction Constructor
*
* @param context The Context of the calling XQuery
*/
public CropFunction(XQueryContext context) {
super(context, signature);
}
/**
* evaluate the call to the xquery crop() function,
* it is really the main entry point of this class
*
* @param args arguments from the crop() function call
* @param contextSequence the Context Sequence to operate on (not used here internally!)
* @return A sequence representing the result of the crop() function call
*
* @see org.exist.xquery.BasicFunction#eval(org.exist.xquery.value.Sequence[], org.exist.xquery.value.Sequence)
*/
@Override
public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {
//was an image and a mime-type speficifed
if(args[0].isEmpty() || args[2].isEmpty()) {
return Sequence.EMPTY_SEQUENCE;
}
//get the maximum dimensions to crop to
int x1 = 0;
int y1 = 0;
int x2 = MAXHEIGHT;
int y2 = MAXWIDTH;
if(!args[1].isEmpty()) {
x1 = ((IntegerValue) args[1].itemAt(0)).getInt();
if(args[1].hasMany()) {
y1 = ((IntegerValue) args[1].itemAt(1)).getInt();
x2 = ((IntegerValue) args[1].itemAt(2)).getInt();
y2 = ((IntegerValue) args[1].itemAt(3)).getInt();
}
}
//get the mime-type
String mimeType = args[2].itemAt(0).getStringValue();
String formatName = mimeType.substring(mimeType.indexOf("/")+1);
//TODO currently ONLY tested for JPEG!!!
Image image = null;
BufferedImage bImage = null;
try {
//get the image data
//get the image data
image = ImageModule.getImage((Base64Binary)args[0].itemAt(0));
// image = ImageModule.getImage((Base64BinaryValueType)args[0].itemAt(0));
// image = ImageIO.read(new ByteArrayInputStream(getImageData((Base64BinaryValueType)args[0].itemAt(0))));
if(image == null) {
logger.error("Unable to read image data!");
return Sequence.EMPTY_SEQUENCE;
}
//crop the image
Image cropImage = Toolkit.getDefaultToolkit().createImage(new FilteredImageSource(image.getSource(), new CropImageFilter(x1, y1, x2, y2)));
if(cropImage instanceof BufferedImage) {
// just in case cropImage is allready an BufferedImage
bImage = (BufferedImage)cropImage;
} else {
bImage = new BufferedImage(cropImage.getHeight(null),
cropImage.getWidth(null),BufferedImage.TYPE_INT_RGB);
Graphics2D g = bImage.createGraphics(); // Paint the image onto the buffered image
g.drawImage(cropImage, 0, 0, null);
g.dispose();
}
ByteArrayOutputStream os = new ByteArrayOutputStream();
ImageIO.write(bImage, formatName, os);
//return the new croped image data
return new Base64Binary(os.toByteArray());
} catch(Exception e) {
throw new XPathException(this, e.getMessage());
}
}
}