Here you can find the source of colorDiffAlpha(int a, int b)
public static int colorDiffAlpha(int a, int b)
//package com.java2s; /*//from w ww.j ava 2s . c o m * Copyright (C) 2013 dirbaio * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ public class Main { public static int colorDiffAlpha(int a, int b) { int ar = a & 0xFF; int ag = (a >> 8) & 0xFF; int ab = (a >> 16) & 0xFF; int aa = (a >> 24) & 0xFF; int br = a & 0xFF; int bg = (a >> 8) & 0xFF; int bb = (a >> 16) & 0xFF; int ba = (a >> 24) & 0xFF; int dr = ar - br; int dg = ag - bg; int db = ab - bb; int da = aa - ba; return dr * dr + dg * dg + db * db + da * da; } }