content: // ===============================================================================
  // Authors: AFRL/RQQD
  // Organization: Air Force Research Laboratory, Aerospace Systems Directorate, Power and Control Division
  // 
  // Copyright (c) 2017 Government of the United State of America, as represented by
  // the Secretary of the Air Force.  No copyright is claimed in the United States under
  // Title 17, U.S. Code.  All Other Rights Reserved.
  // ===============================================================================
  
  /*
   * GRAL: GRAphing Library for Java(R)
   *
   * (C) Copyright 2009-2013 Erich Seifert <dev[at]erichseifert.de>,
   * Michael Seifert <mseifert[at]error-reports.org>
   *
   * This file is part of GRAL.
   *
   * GRAL 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 3 of the License, or
   * (at your option) any later version.
   *
   * GRAL 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 GRAL.  If not, see <http://www.gnu.org/licenses/>.
   */
  package de.erichseifert.gral.io.data;
  
  import java.awt.image.BufferedImage;
  import java.io.IOException;
  import java.io.OutputStream;
  import java.text.MessageFormat;
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  
  import javax.imageio.ImageIO;
  
  import de.erichseifert.gral.data.DataSource;
  import de.erichseifert.gral.io.IOCapabilities;
  import de.erichseifert.gral.util.MathUtils;
  import de.erichseifert.gral.util.Messages;
  
  
  /**
   * Class that writes a data source to a binary image file. This class
   * shouldn't be used directly but using the {@link DataWriterFactory}.
   */
  public class ImageWriter extends AbstractDataWriter {
  	static {
  		addCapabilities(new IOCapabilities(
  			"BMP", //$NON-NLS-1$
  			Messages.getString("ImageIO.bmpDescription"), //$NON-NLS-1$
  			"image/bmp", //$NON-NLS-1$
  			new String[] {"bmp", "dib"} //$NON-NLS-1$ //$NON-NLS-2$
  		));
  
  		addCapabilities(new IOCapabilities(
  			"GIF", //$NON-NLS-1$
  			Messages.getString("ImageIO.gifDescription"), //$NON-NLS-1$
  			"image/gif", //$NON-NLS-1$
  			new String[] {"gif"} //$NON-NLS-1$
  		));
  
  		addCapabilities(new IOCapabilities(
  			"JPEG/JFIF", //$NON-NLS-1$
  			Messages.getString("ImageIO.jpegDescription"), //$NON-NLS-1$
  			"image/jpeg", //$NON-NLS-1$
  			new String[] {
  				"jpg", "jpeg", "jpe", //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
  				"jif", "jfif", "jfi"} //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
  		));
  
  		addCapabilities(new IOCapabilities(
  			"PNG", //$NON-NLS-1$
  			Messages.getString("ImageIO.pngDescription"), //$NON-NLS-1$
  			"image/png", //$NON-NLS-1$
  			new String[] {"png"} //$NON-NLS-1$
  		));
  
  		addCapabilities(new IOCapabilities(
  			"WBMP", //$NON-NLS-1$
  			Messages.getString("ImageIO.wbmpDescription"), //$NON-NLS-1$
  			"image/vnd.wap.wbmp", //$NON-NLS-1$
  			new String[] {"wbmp"} //$NON-NLS-1$
  		));
  	}
  
  	/**
  	 * Creates a new instance with the specified MIME type.
  	 * @param mimeType MIME type of the file format to be read.
  	 */
  	public ImageWriter(String mimeType) {
  		super(mimeType);
  		setDefault("factor", 1.0); //$NON-NLS-1$
  		setDefault("offset", 0.0); //$NON-NLS-1$
  	}
  
  	/**
  	 * Stores the specified data source.
  	 * @param data DataSource to be stored.
  	 * @param output OutputStream to be written to.
  	 * @throws IOException if writing the data failed
  	 */
  	public void write(DataSource data, OutputStream output) throws IOException {
  		int w = data.getColumnCount();
  		int h = data.getRowCount();
  
  		double factor = this.<Number>getSetting("factor").doubleValue(); //$NON-NLS-1$
  		double offset = this.<Number>getSetting("offset").doubleValue(); //$NON-NLS-1$
  
  		byte[] pixelData = new byte[w*h];
  		int pos = 0;
  		for (int y = 0; y < h; y++) {
  			for (int x = 0; x < w; x++) {
  				Comparable<?> cell = data.get(x, y);
  				if (!(cell instanceof Number)) {
  					continue;
  				}
  				Number numericCell = (Number) cell;
  				double value = numericCell.doubleValue()*factor + offset;
  				byte v = (byte) Math.round(MathUtils.limit(value, 0.0, 255.0));
  				pixelData[pos++] = v;
  			}
  		}
  
          BufferedImage image =
          	new BufferedImage(w, h, BufferedImage.TYPE_BYTE_GRAY);
          image.getRaster().setDataElements(0, 0, w, h, pixelData);
  
          Iterator<javax.imageio.ImageWriter> writers =
          	ImageIO.getImageWritersByMIMEType(getMimeType());
          try {
          	javax.imageio.ImageWriter writer = writers.next();
          	writer.setOutput(ImageIO.createImageOutputStream(output));
          	writer.write(image);
          } catch (NoSuchElementException e) {
          	throw new IOException(MessageFormat.format(
          			"No writer found for MIME type {0}.", getMimeType())); //$NON-NLS-1$
          }
  	}
  
  }
  