view servlet/src/digilib/image/JIMIDocuImage.java @ 71:d493563ef672

New servlet version 1.5b. Mostly cleanup. Global parameters for digilib now in DigilibConfiguration, per request parameters are now all in DigilibRequest. The DocuImage implementation can be selected by the configuration docuimage-class. Pixel-by-pixel view implemented with "mo=clip".
author robcast
date Fri, 24 Jan 2003 21:40:59 +0100
parents 0ff3ede32060
children 3b8797fc3e90
line wrap: on
line source

/* JAIDocuImage -- Image class implementation using JIMI toolkit

  Digital Image Library servlet components

  Copyright (C) 2001, 2002 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 javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;

import com.sun.jimi.core.*;
import com.sun.jimi.core.raster.*;
import com.sun.jimi.core.filters.*;

import java.awt.*;
import java.awt.image.*;

import digilib.*;
import digilib.io.*;


public class JIMIDocuImage extends DocuImageImpl {

  private JimiRasterImage img;
  private ImageProducer imgp;

  public JIMIDocuImage() {
  }

  public JIMIDocuImage(Utils u) {
    util = u;
  }

  /**
   *  load image file
   */
  public void loadImage(File f) throws FileOpException {
    System.gc();
    try {
    img = Jimi.getRasterImage(f.toURL());
    } catch (java.net.MalformedURLException e) {
      util.dprintln(3, "ERROR(loadImage): MalformedURLException");
    } catch (JimiException e) {
      util.dprintln(3, "ERROR(loadImage): JIMIException");
      throw new FileOpException("Unable to load File!"+e);
    }
    if (img == null) {
      util.dprintln(3, "ERROR(loadImage): unable to load file");
      throw new FileOpException("Unable to load File!");
    }
  }

  /**
   *  write image of type mt to Stream
   */
  public void writeImage(String mt, ServletResponse res)
         throws FileOpException {
    try {
    // setup output
    res.setContentType(mt);
    // render output
    Jimi.putImage(mt, imgp, res.getOutputStream());

    } catch (JimiException e) {
      throw new FileOpException("Error writing image!"+e);
    } catch (IOException e) {
      throw new FileOpException("Error writing image."+e);
    }
  }

  public int getWidth() {
    if (img != null) {
      return img.getWidth();
    }
    return 0;
  }

  public int getHeight() {
    if (img != null) {
      return img.getHeight();
    }
    return 0;
  }


  /**
   *  crop and scale image
   *    take rectangle width,height at position x_off,y_off
   *    and scale by scale
   */
   public void cropAndScale(int x_off, int y_off, int width, int height,
         float scale, int qual) throws ImageOpException {

    ImageFilter scaleFilter;
    int destWidth = (int)(scale * (float)width);
    int destHeight = (int)(scale * (float)height);

    // setup Crop
    ImageProducer croppedImg = img.getCroppedImageProducer(x_off, y_off, width, height);
    //util.dprintln(3, "CROP:"+croppedImg.getWidth()+"x"+croppedImg.getHeight()); //DEBUG

    if (croppedImg == null) {
      util.dprintln(2, "ERROR(cropAndScale): error in crop");
      throw new ImageOpException("Unable to crop");
    }

    // setup scale and interpolation quality
    if (qual > 0) {
      util.dprintln(4, "quality q1");
      scaleFilter = new AreaAverageScaleFilter(destWidth, destHeight);
    } else {
      util.dprintln(4, "quality q0");
      scaleFilter = new ReplicatingScaleFilter(destWidth, destHeight);
    }

    ImageProducer scaledImg = new FilteredImageSource(croppedImg, scaleFilter);

    if (scaledImg == null) {
      util.dprintln(2, "ERROR(cropAndScale): error in scale");
      throw new ImageOpException("Unable to scale");
    }

    imgp = scaledImg;
  }

}