--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/servlet/src/digilib/image/JAIImageLoaderDocuImage.java	Wed Nov 17 18:17:34 2004 +0100
@@ -0,0 +1,184 @@
+/* JAIImageLoaderDocuImage -- Image class implementation using JAI's ImageLoader Plugin
+
+  Digital Image Library servlet components
+
+  Copyright (C) 2002, 2003 Robert Casties (robcast@mail.berlios.de)
+
+  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.
+   
+  Please read license.txt for the full details. A copy of the GPL
+  may be found at http://www.gnu.org/copyleft/lgpl.html
+
+  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+*/
+
+package digilib.image;
+
+import java.awt.Rectangle;
+import java.awt.image.renderable.ParameterBlock;
+import java.io.File;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.RandomAccessFile;
+import java.util.Iterator;
+
+import javax.imageio.ImageIO;
+import javax.imageio.ImageReadParam;
+import javax.imageio.ImageReader;
+import javax.imageio.stream.FileImageInputStream;
+import javax.imageio.stream.ImageInputStream;
+import javax.media.jai.JAI;
+
+import digilib.io.FileOpException;
+import digilib.io.ImageFile;
+
+/** DocuImage implementation using the Java Advanced Imaging API and the ImageLoader
+ * API of Java 1.4.
+ */
+public class JAIImageLoaderDocuImage extends JAIDocuImage {
+
+	/** ImageIO image reader */
+	protected ImageReader reader;
+	/** current image file */
+	protected File imgFile;
+
+	/* loadSubimage is supported. */
+	public boolean isSubimageSupported() {
+		return true;
+	}
+
+	public int getHeight() {
+		int h = 0;
+		try {
+			if (img == null) {
+				h = reader.getHeight(0);
+			} else {
+				h = img.getHeight();
+			}
+		} catch (IOException e) {
+			logger.debug("error in getHeight", e);
+		}
+		return h;
+	}
+
+	public int getWidth() {
+		int w = 0;
+		try {
+			if (img == null) {
+				w = reader.getWidth(0);
+			} else {
+				w = img.getWidth();
+			}
+		} catch (IOException e) {
+			logger.debug("error in getHeight", e);
+		}
+		return w;
+	}
+
+	/* Load an image file into the Object. */
+	public void loadImage(ImageFile f) throws FileOpException {
+		logger.debug("loadImage: "+f);
+		//System.gc();
+		img = JAI.create("ImageRead", f.getAbsolutePath());
+		if (img == null) {
+			throw new FileOpException("Unable to load File!");
+		}
+	}
+
+	/* Get an ImageReader for the image file. */
+	public ImageReader getReader(ImageFile f) throws IOException {
+		logger.debug("preloadImage: "+f);
+		//System.gc();
+		RandomAccessFile rf = new RandomAccessFile(f, "r");
+		ImageInputStream istream = new FileImageInputStream(rf);
+		//Iterator readers = ImageIO.getImageReaders(istream);
+		Iterator readers = ImageIO.getImageReadersByMIMEType(f.getMimetype());
+		if (! readers.hasNext()) {
+			throw new FileOpException("Unable to load File!");
+		}
+		reader = (ImageReader) readers.next();
+		logger.debug("JAIImageIO: this reader: " + reader.getClass());
+		while (readers.hasNext()) {
+			logger.debug("  next reader: " + readers.next().getClass());
+		}
+		reader.setInput(istream);
+		return reader;
+	}
+
+	/* Load an image file into the Object. */
+	public void loadSubimage(ImageFile f, Rectangle region, int prescale)
+		throws FileOpException {
+		logger.debug("loadSubimage: "+f);
+		//System.gc();
+		try {
+			if ((reader == null) || (imgFile != f)) {
+				getReader(f);
+			}
+			ImageReadParam readParam = reader.getDefaultReadParam();
+			readParam.setSourceRegion(region);
+			readParam.setSourceSubsampling(prescale, prescale, 0, 0);
+			img = reader.read(0, readParam);
+			/* JAI imageread seems to ignore the readParam :-(
+			ImageInputStream istream = (ImageInputStream) reader.getInput();
+			ParameterBlockJAI pb = new ParameterBlockJAI("imageread");
+			pb.setParameter("Input", istream);
+			pb.setParameter("ReadParam", readParam);
+			pb.setParameter("Reader", reader);
+			img = JAI.create("imageread", pb);
+			*/
+		} catch (IOException e) {
+			throw new FileOpException("Unable to load File!");
+		}
+		if (img == null) {
+			throw new FileOpException("Unable to load File!");
+		}
+		imgFile = f;
+	}
+
+
+	/* Write the current image to an OutputStream. */
+	public void writeImage(String mt, OutputStream ostream)
+		throws FileOpException {
+		logger.debug("writeImage");
+		try {
+			// setup output
+			ParameterBlock pb3 = new ParameterBlock();
+			pb3.addSource(img);
+			pb3.add(ostream);
+			if (mt == "image/jpeg") {
+				pb3.add("JPEG");
+			} else if (mt == "image/png") {
+				pb3.add("PNG");
+			} else {
+				// unknown mime type
+				throw new FileOpException("Unknown mime type: " + mt);
+			}
+			// render output
+			JAI.create("ImageWrite", pb3);
+		} catch (IOException e) {
+			throw new FileOpException("Error writing image.");
+		}
+	}
+
+	/* (non-Javadoc)
+	 * @see java.lang.Object#finalize()
+	 */
+	protected void finalize() throws Throwable {
+		dispose();
+		super.finalize();
+	}
+
+	public void dispose() {
+		// we must dispose the ImageReader because it keeps the filehandle open!
+		reader.dispose();
+		reader = null;
+		img = null;
+	}
+
+}