1 /*
2  * Copyright (c) 2000, 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 import java.awt.image.BufferedImage;
25 import java.awt.image.ColorModel;
26 import java.awt.image.Raster;
27 
28 // Utility to compare two BufferedImages for RGB equality
29 public class ImageCompare {
30 
compare(BufferedImage oldimg, BufferedImage newimg)31     public static void compare(BufferedImage oldimg,
32                                BufferedImage newimg) {
33         int width = oldimg.getWidth();
34         int height = oldimg.getHeight();
35         if (newimg.getWidth() != width || newimg.getHeight() != height) {
36             throw new RuntimeException("Dimensions changed!");
37         }
38 
39         Raster oldras = oldimg.getRaster();
40         ColorModel oldcm = oldimg.getColorModel();
41         Raster newras = newimg.getRaster();
42         ColorModel newcm = newimg.getColorModel();
43 
44         for (int j = 0; j < height; j++) {
45             for (int i = 0; i < width; i++) {
46                 Object oldpixel = oldras.getDataElements(i, j, null);
47                 int oldrgb = oldcm.getRGB(oldpixel);
48                 int oldalpha = oldcm.getAlpha(oldpixel);
49 
50                 Object newpixel = newras.getDataElements(i, j, null);
51                 int newrgb = newcm.getRGB(newpixel);
52                 int newalpha = newcm.getAlpha(newpixel);
53 
54                 if (newrgb != oldrgb ||
55                     newalpha != oldalpha) {
56                     throw new RuntimeException("Pixels differ at " + i +
57                                                ", " + j);
58                 }
59             }
60         }
61     }
62 }
63