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 
  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 }