Java tutorial
//package com.java2s; /* * Copyright (C) 2011 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.awt.image.BufferedImage; import java.awt.image.Raster; public class Main { /** * Trims the transparent pixels from the given {@link BufferedImage} (returns a sub-image). * * @param source The source image. * @return A new, trimmed image, or the source image if no trim is performed. */ public static BufferedImage trimmedImage(BufferedImage source) { final int minAlpha = 1; final int srcWidth = source.getWidth(); final int srcHeight = source.getHeight(); Raster raster = source.getRaster(); int l = srcWidth, t = srcHeight, r = 0, b = 0; int alpha, x, y; int[] pixel = new int[4]; for (y = 0; y < srcHeight; y++) { for (x = 0; x < srcWidth; x++) { raster.getPixel(x, y, pixel); alpha = pixel[3]; if (alpha >= minAlpha) { l = Math.min(x, l); t = Math.min(y, t); r = Math.max(x, r); b = Math.max(y, b); } } } if (l > r || t > b) { // No pixels, couldn't trim return source; } return source.getSubimage(l, t, r - l + 1, b - t + 1); } }