001/*
002Copyright 2006 Jerry Huxtable
003
004Licensed under the Apache License, Version 2.0 (the "License");
005you may not use this file except in compliance with the License.
006You may obtain a copy of the License at
007
008   http://www.apache.org/licenses/LICENSE-2.0
009
010Unless required by applicable law or agreed to in writing, software
011distributed under the License is distributed on an "AS IS" BASIS,
012WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013See the License for the specific language governing permissions and
014limitations under the License.
015*/
016
017package com.jhlabs.image;
018
019import java.awt.*;
020import java.awt.image.*;
021
022/**
023 * Scales an image using the area-averaging algorithm, which can't be done with AffineTransformOp.
024 */
025public class ScaleFilter extends AbstractBufferedImageOp {
026
027        private int width;
028        private int height;
029
030    /**
031     * Construct a ScaleFilter.
032     */
033        public ScaleFilter() {
034                this(32, 32);
035        }
036
037    /**
038     * Construct a ScaleFilter.
039     * @param width the width to scale to
040     * @param height the height to scale to
041     */
042        public ScaleFilter( int width, int height ) {
043                this.width = width;
044                this.height = height;
045        }
046
047    public BufferedImage filter( BufferedImage src, BufferedImage dst ) {
048                if ( dst == null ) {
049                        ColorModel dstCM = src.getColorModel();
050                        dst = new BufferedImage(dstCM, dstCM.createCompatibleWritableRaster( width, height ), dstCM.isAlphaPremultiplied(), null);
051                }
052
053                Image scaleImage = src.getScaledInstance( width, height, Image.SCALE_AREA_AVERAGING );
054                Graphics2D g = dst.createGraphics();
055                g.drawImage( scaleImage, 0, 0, width, height, null );
056                g.dispose();
057
058        return dst;
059    }
060
061        public String toString() {
062                return "Distort/Scale";
063        }
064
065}