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
31import java.awt.AlphaComposite;
32import java.awt.Color;
33import java.awt.Graphics2D;
34import java.awt.image.BufferedImage;
35import java.io.ByteArrayInputStream;
36import java.io.ByteArrayOutputStream;
37
38import javax.imageio.ImageIO;
39
40public 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}
132