1 /*
   2  * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug 4888478
  27  * @summary Test that colors do not distort when buffered image with
  28  *          premultiplied alpha is encoded to png format
  29  */
  30 
  31 import java.awt.AlphaComposite;
  32 import java.awt.Color;
  33 import java.awt.Graphics2D;
  34 import java.awt.image.BufferedImage;
  35 import java.io.ByteArrayInputStream;
  36 import java.io.ByteArrayOutputStream;
  37 
  38 import javax.imageio.ImageIO;
  39 
  40 public class PngPremultAlphaTest {
  41     protected static int width = 100;
  42     protected static int height = 100;
  43 
  44     protected static String format = "png";
  45 
  46     protected static int[] iBufferedImageTypes = {
  47         BufferedImage.TYPE_INT_RGB,
  48         BufferedImage.TYPE_INT_ARGB,
  49         BufferedImage.TYPE_4BYTE_ABGR_PRE,
  50         BufferedImage.TYPE_INT_ARGB_PRE
  51     };
  52 
  53     protected static String[] strBufferedImageTypes = {
  54         "TYPE_INT_RGB",
  55         "TYPE_INT_ARGB",
  56         "BufferedImage.TYPE_4BYTE_ABGR_PRE",
  57         "BufferedImage.TYPE_INT_ARGB_PRE"
  58     };
  59 
  60     public static void main(String[] arg) {
  61         for(int i=0; i<iBufferedImageTypes.length; i++) {
  62             System.out.println("Test for " + strBufferedImageTypes[i]);
  63             doTest(iBufferedImageTypes[i]);
  64         }
  65     }
  66 
  67     public static void doTest(int type) {
  68         try {
  69             BufferedImage src = new BufferedImage(100, 100,
  70                                                   type);
  71             Graphics2D g = src.createGraphics();
  72             g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC, 0.5f));
  73             g.setColor(new Color(0x20, 0x40, 0x60));
  74             g.fillRect(0,0,100,100);
  75 
  76             int[] samples = new int[src.getData().getNumBands()];
  77             src.getData().getPixels(0,0,1,1,samples);
  78             for(int i=0; i<samples.length; i++) {
  79                 System.out.println("sample["+i+"]="+Integer.toHexString(samples[i]));
  80             }
  81 
  82             ByteArrayOutputStream baos = new ByteArrayOutputStream();
  83             ImageIO.write(src, format, baos);
  84             baos.close();
  85 
  86 
  87             ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
  88             BufferedImage dst = ImageIO.read(bais);
  89 
  90             isSameColors(src, dst);
  91         } catch (Exception e) {
  92             e.printStackTrace();
  93             throw new RuntimeException("Test failed.");
  94         }
  95     }
  96 
  97     private static boolean isSameColors(BufferedImage src, BufferedImage dst) {
  98         Object dstPixel = dst.getRaster().getDataElements(width/2, height/2, null);
  99         Object srcPixel = src.getRaster().getDataElements(width/2, height/2, null);
 100 
 101         // take into account the rounding error
 102         if ( Math.abs(src.getColorModel().getRed(srcPixel) -  dst.getColorModel().getRed(dstPixel)) > 1
 103              || Math.abs(src.getColorModel().getGreen(srcPixel) - dst.getColorModel().getGreen(dstPixel)) > 1
 104              || Math.abs(src.getColorModel().getBlue(srcPixel) - dst.getColorModel().getBlue(dstPixel)) > 1) {
 105             showPixel(src, width/2, height/2);
 106             showPixel(dst, width/2, height/2);
 107 
 108             throw new RuntimeException( "Colors are different: "
 109                                         + Integer.toHexString(src.getColorModel().getRGB(srcPixel))
 110                                         + " and "
 111                                         + Integer.toHexString(dst.getColorModel().getRGB(dstPixel)));
 112         }
 113         return true;
 114     }
 115 
 116     private static void showPixel(BufferedImage src, int x, int y) {
 117         System.out.println("Img is " + src);
 118         System.out.println("CM is " + src.getColorModel().getClass().getName());
 119         Object p = src.getRaster().getDataElements(x, y, null);
 120         System.out.println("RGB:   " +
 121                            Integer.toHexString(src.getColorModel().getRGB(p)));
 122         System.out.println("Red:   " +
 123                            Integer.toHexString(src.getColorModel().getRed(p)));
 124         System.out.println("Green: " +
 125                            Integer.toHexString(src.getColorModel().getGreen(p)));
 126         System.out.println("Blue:  " +
 127                            Integer.toHexString(src.getColorModel().getBlue(p)));
 128         System.out.println("Alpha: " +
 129                            Integer.toHexString(src.getColorModel().getAlpha(p)));
 130     }
 131 }