/*
* org.openmicroscopy.shoola.util.image.io.Encoder
*
*------------------------------------------------------------------------------
* Copyright (C) 2006 University of Dundee. All rights reserved.
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*------------------------------------------------------------------------------
*/
package org.openmicroscopy.shoola.util.image.io;
//Java imports
import java.awt.color.ColorSpace;
import java.awt.image.BufferedImage;
import java.io.DataOutputStream;
//Third-party libraries
//Application-internal dependencies
/**
* Top class for encoder. Sub-classes override the {@link #write()} and
* {@link #init()} methods.
*
* @author Jean-Marie Burel
* <a href="mailto:j.burel@dundee.ac.uk">j.burel@dundee.ac.uk</a>
* @author <br>Andrea Falconi
* <a href="mailto:a.falconi@dundee.ac.uk">
* a.falconi@dundee.ac.uk</a>
* @version 2.2
* <small>
* (<b>Internal version:</b> $Revision$ $Date$)
* </small>
* @since OME2.2
*/
public abstract class Encoder
{
/** Identifies the <code>RED</code> color band. */
static final int RED_BAND = 0;
/** Identifies the <code>GREEN</code> color band. */
static final int GREEN_BAND = 1;
/** Identifies the <code>BLUE</code> color band. */
static final int BLUE_BAND = 2;
/** The output stream. */
protected DataOutputStream output;
/** The image to encode. */
protected BufferedImage image;
/** The width of the image. */
protected int imageWidth;
/** The height of the image. */
protected int imageHeight;
/** The color type of the image. */
protected int colorType;
/**
* Controls if the color model associated to the specified image is
* supported. Note that the only supported models are Gray and RGB.
*
* @param img The image to encode.
* @return The color type.
* */
private int checkColorModel(BufferedImage img)
{
int c = img.getColorModel().getColorSpace().getType();
if (c != ColorSpace.TYPE_RGB &&
c != ColorSpace.TYPE_GRAY)
throw new IllegalArgumentException("Color Type not supported");
return c;
}
/**
* Initializes the encoder. Sub-classes will set the constants required.
*
* @param image The image to transfer.
* @param output The stream to write the transformed image
*/
public Encoder(BufferedImage image, DataOutputStream output)
{
if (output == null)
throw new IllegalArgumentException("Output not valid");
if (image == null)
throw new IllegalArgumentException("Image to encode not valid");
colorType = checkColorModel(image);
this.image = image;
this.imageHeight = image.getWidth();
this.imageWidth = image.getHeight();
this.output = output;
init();
}
/**
* Returns the output stream.
*
* @return See above.
*/
public DataOutputStream getOutput() { return output; }
/**
* Writes the encoded image. Sub-classes override this method.
* @throws EncoderException Exception thrown if an error occurred during the
* encoding process.
*/
public abstract void write()
throws EncoderException;
/** Initializes the values. Sub-classes override this method. */
protected abstract void init();
}