package com.bbn.openmap.image;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
/*
*
* Copyright (c) 2007, Sun Microsystems, Inc
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* * Neither the name of the TimingFramework project nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* This code comes from the book "Filthy Rich Clients" Chapter 4.
* It is optimized for fast scaling.
*
* @author Chet Hasse
* */
public class ImageScaler {
/**
* Progressive bilinear scaling: for any downscale size, scale
* iteratively by halves using BILINEAR filtering until the proper
* size is reached.
*/
public static Image getOptimalScalingImage(Image inputImage,
int startSize, int endSize) {
int currentSize = startSize;
Image currentImage = inputImage;
int delta = currentSize - endSize;
int nextPow2 = currentSize >> 1;
while (currentSize > 1) {
if (delta <= nextPow2) {
if (currentSize != endSize) {
BufferedImage tmpImage = new BufferedImage(endSize,
endSize, BufferedImage.TYPE_INT_RGB);
Graphics g = tmpImage.getGraphics();
((Graphics2D)g).setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g.drawImage(currentImage, 0, 0, tmpImage.getWidth(),
tmpImage.getHeight(), null);
currentImage = tmpImage;
}
return currentImage;
} else {
BufferedImage tmpImage = new BufferedImage(currentSize >> 1,
currentSize >> 1, BufferedImage.TYPE_INT_RGB);
Graphics g = tmpImage.getGraphics();
((Graphics2D)g).setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g.drawImage(currentImage, 0, 0, tmpImage.getWidth(),
tmpImage.getHeight(), null);
currentImage = tmpImage;
currentSize = currentImage.getWidth(null);
delta = currentSize - endSize;
nextPow2 = currentSize >> 1;
}
}
return currentImage;
}
}