Mediafilter to create diagonal watermarks with Java

WaterMark.java

/**
 * The contents of this file are subject to the license and copyright
 * detailed in the LICENSE and NOTICE files at the root of the source
 * tree and available online at
 *
 * http://www.dspace.org/license/
 */
package org.dspace.app.mediafilter;

import org.dspace.core.ConfigurationManager;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.awt.image.BufferedImageOp;
import java.awt.image.ConvolveOp;
import java.awt.image.Kernel;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;
import static org.dspace.app.mediafilter.MediaFilterManager.getCurrentItem;
import javax.swing.ImageIcon;

/**
 * Filter image bitstreams, scaling the image to be within the bounds of
 * thumbnail.maxwidth, thumbnail.maxheight, the size we want our thumbnail to be
 * no bigger than. Creates only JPEGs.
 *
 * @author Jason Sherman <jsherman@usao.edu>
 */
public class WaterMark extends MediaFilter
{
    public String getFilteredName(String oldFilename)
    {
        return oldFilename + ".preview.jpg";
    }

    /**
     * @return String bundle name
     *  
     */
    public String getBundleName()
    {
        return "WATERMARK_PREVIEW";
    }

    /**
     * @return String bitstreamformat
     */
    public String getFormatString()
    {
        return "JPEG";
    }

    /**
     * @return String description
     */
    public String getDescription()
    {
        return "Generated Watermarked Preview";
    }

   
    /**
     * @param source
     *            source input stream
     * 
     * @return InputStream the resulting input stream
     */
    public InputStream getDestinationStream(InputStream source)
            throws Exception
    {
        // read in bitstream's image
        BufferedImage buf = ImageIO.read(source);

        // get config params
        float xmax = (float) ConfigurationManager
                .getIntProperty("webui.preview.maxwidth");
        float ymax = (float) ConfigurationManager
                .getIntProperty("webui.preview.maxheight");
        boolean blurring = (boolean) ConfigurationManager
                .getBooleanProperty("webui.preview.blurring");
        boolean hqscaling = (boolean) ConfigurationManager
                .getBooleanProperty("webui.preview.hqscaling");
        int brandHeight = ConfigurationManager.getIntProperty("webui.preview.brand.height");
        String brandFont = ConfigurationManager.getProperty("webui.preview.brand.font");
        int brandFontPoint = ConfigurationManager.getIntProperty("webui.preview.brand.fontpoint");
        String waterMarkLabel = ConfigurationManager.getProperty("webui.preview.watermark");
        
        // now get the image dimensions
        float xsize = (float) buf.getWidth(null);
        float ysize = (float) buf.getHeight(null);

        // if verbose flag is set, print out dimensions
        // to STDOUT
        if (MediaFilterManager.isVerbose)
        {
            System.out.println("original size: " + xsize + "," + ysize);
        }

        // scale by x first if needed
        if (xsize > xmax)
        {
            // calculate scaling factor so that xsize * scale = new size (max)
            float scaleFactor = xmax / xsize;

            // if verbose flag is set, print out extracted text
            // to STDOUT
            if (MediaFilterManager.isVerbose)
            {
                System.out.println("x scale factor: " + scaleFactor);
            }

            // now reduce x size
            // and y size
            xsize = xsize * scaleFactor;
            ysize = ysize * scaleFactor;

            // if verbose flag is set, print out extracted text
            // to STDOUT
            if (MediaFilterManager.isVerbose)
            {
                System.out.println("new size: " + xsize + "," + ysize);
            }
        }

        // scale by y if needed
        if (ysize > ymax)
        {
            float scaleFactor = ymax / ysize;

            // now reduce x size
            // and y size
            xsize = xsize * scaleFactor;
            ysize = ysize * scaleFactor;
        }

        // if verbose flag is set, print details to STDOUT
        if (MediaFilterManager.isVerbose)
        {
            System.out.println("created thumbnail size: " + xsize + ", "
                    + ysize);
        }

        // create an image buffer for the preview with the new xsize, ysize
        // we add
        BufferedImage branded = new BufferedImage((int) xsize, (int) ysize + brandHeight,
                BufferedImage.TYPE_INT_RGB);

        // Use blurring if selected in config.
        // a little blur before scaling does wonders for keeping moire in check.
        if (blurring)
        {
                // send the buffered image off to get blurred.
                buf = getBlurredInstance((BufferedImage) buf);
        }

        // Use high quality scaling method if selected in config.
        // this has a definite performance penalty.
        if (hqscaling)
        {
                // send the buffered image off to get an HQ downscale.
                buf = getScaledInstance((BufferedImage) buf, (int) xsize, (int) ysize,
                        (Object) RenderingHints.VALUE_INTERPOLATION_BICUBIC, (boolean) true);
        }

        // now render the image into the preview buffer
        //Graphics2D g2d = branded.createGraphics();
        //g2d.drawImage(buf, 0, 0, (int) xsize, (int) ysize, null);

        //Brand brand = new Brand((int) xsize, brandHeight, new Font(brandFont, Font.PLAIN, brandFontPoint), 5);
		//BufferedImage brandImage = brand.create(ConfigurationManager.getProperty("webui.preview.brand"),
		//										ConfigurationManager.getProperty("webui.preview.brand.abbrev"),
		//										MediaFilterManager.getCurrentItem() == null ? "" : "hdl:" + MediaFilterManager.getCurrentItem().getHandle());

        String watermark = waterMarkLabel;
        ImageIcon photo = new ImageIcon(buf);

        BufferedImage bufferedImage = new BufferedImage(buf.getWidth(),
                buf.getHeight(), BufferedImage.TYPE_INT_RGB);
        Graphics2D g2d = (Graphics2D)bufferedImage.getGraphics();
        g2d.drawImage(photo.getImage(), 0, 0, null);

        //Create an alpha composite of 60%
        AlphaComposite alpha = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.6f);
        g2d.setComposite(alpha);

        g2d.setColor(Color.white);
        g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
                RenderingHints.VALUE_TEXT_ANTIALIAS_ON);

        // Move our origin to the center
        g2d.translate(photo.getIconWidth() / 2.0f, photo.getIconHeight() / 2.0f);

        //Font f1 = new Font("Arial", Font.BOLD, 24);
        Font f1 = new Font(brandFont, Font.BOLD, brandFontPoint);
        g2d.setFont(f1);

        FontMetrics fontMetrics = g2d.getFontMetrics();
        Rectangle2D rect = fontMetrics.getStringBounds(watermark, g2d);

        // Create a rotation transform to rotate the text based on the diagonal
        // angle of the picture aspect ratio
        AffineTransform at2 = new AffineTransform();
        double opad = photo.getIconHeight() / (double)photo.getIconWidth();
        double angle = Math.toDegrees(Math.atan(opad));
        double idegrees = -1 * angle;
        double theta = (2 * Math.PI * idegrees) / 360;
        at2.rotate(theta);
        g2d.transform(at2);

        //Now reposition our coordinates based on size (same as we would normally
        //do to center on straight line but based on starting at center
        float x1 = (int)rect.getWidth() / 2.0f *-1;
        float y1 = (int)rect.getHeight() / 2.0f;
        g2d.translate(x1, y1);

        //finally let's draw the string
        g2d.drawString(watermark, 0.0f, 0.0f);

        //Free graphic resources
        g2d.dispose();

        // now create an input stream for the thumbnail buffer and return it
        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        ImageIO.write(bufferedImage, "jpeg", baos);

        // now get the array
        ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());

        return bais; // hope this gets written out before its garbage collected!
	}

    public BufferedImage getNormalizedInstance(BufferedImage buf)
    {
     int type = (buf.getTransparency() == Transparency.OPAQUE) ?
            BufferedImage.TYPE_INT_RGB : BufferedImage.TYPE_INT_ARGB_PRE;
     int w, h;
     w = buf.getWidth();
     h = buf.getHeight();
     BufferedImage normal = new BufferedImage(w, h, type);
     Graphics2D g2d = normal.createGraphics();
     g2d.drawImage(buf, 0, 0, w, h, Color.WHITE, null);
     g2d.dispose();
     return normal;
    }

    public BufferedImage getBlurredInstance(BufferedImage buf)
    {
    /**
     * Convenience method that returns a blurred instance of the
     * provided {@code BufferedImage}.
     *
     */

     buf = getNormalizedInstance(buf);

     // kernel for blur op
     float[] matrix = {
        0.111f, 0.111f, 0.111f,
        0.111f, 0.111f, 0.111f,
        0.111f, 0.111f, 0.111f,
      };

     // perform the blur and return the blurred version.
     BufferedImageOp blur = new ConvolveOp( new Kernel(3, 3, matrix) );
     BufferedImage blurbuf = blur.filter(buf, null);
     return blurbuf;
    }

    /**
     * Convenience method that returns a scaled instance of the
     * provided {@code BufferedImage}.
     *
     * @param buf the original image to be scaled
     * @param targetWidth the desired width of the scaled instance,
     *    in pixels
     * @param targetHeight the desired height of the scaled instance,
     *    in pixels
     * @param hint one of the rendering hints that corresponds to
     *    {@code RenderingHints.KEY_INTERPOLATION} (e.g.
     *    {@code RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR},
     *    {@code RenderingHints.VALUE_INTERPOLATION_BILINEAR},
     *    {@code RenderingHints.VALUE_INTERPOLATION_BICUBIC})
     * @param higherQuality if true, this method will use a multi-step
     *    scaling technique that provides higher quality than the usual
     *    one-step technique (only useful in downscaling cases, where
     *    {@code targetWidth} or {@code targetHeight} is
     *    smaller than the original dimensions, and generally only when
     *    the {@code BILINEAR} hint is specified)
     * @return a scaled version of the original {@code BufferedImage}
     */
    public BufferedImage getScaledInstance(BufferedImage buf,
                                           int targetWidth,
                                           int targetHeight,
                                           Object hint,
                                           boolean higherQuality)
    {
        int type = (buf.getTransparency() == Transparency.OPAQUE) ?
            BufferedImage.TYPE_INT_RGB : BufferedImage.TYPE_INT_ARGB;
        BufferedImage scalebuf = (BufferedImage)buf;
        int w, h;
        if (higherQuality) {
            // Use multi-step technique: start with original size, then
            // scale down in multiple passes with drawImage()
            // until the target size is reached
            w = buf.getWidth();
            h = buf.getHeight();
        } else {
            // Use one-step technique: scale directly from original
            // size to target size with a single drawImage() call
            w = targetWidth;
            h = targetHeight;
        }

        do {
            if (higherQuality && w > targetWidth) {
                w /= 2;
                if (w < targetWidth) {
                    w = targetWidth;
                }
            }

            if (higherQuality && h > targetHeight) {
                h /= 2;
                if (h < targetHeight) {
                    h = targetHeight;
                }
            }

            BufferedImage tmp = new BufferedImage(w, h, type);
            Graphics2D g2d = tmp.createGraphics();
            g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, hint);
            g2d.drawImage(scalebuf, 0, 0, w, h, Color.WHITE, null);
            g2d.dispose();

            scalebuf = tmp;
        } while (w != targetWidth || h != targetHeight);

        return scalebuf;
    }
}