Here you can find the source of thresholdImage(BufferedImage image, int threshold)
| Parameter | Description |
|---|---|
| image | the image to convert. Remains untouched. |
| threshold | the threshold in [0,255] |
public static BufferedImage thresholdImage(BufferedImage image, int threshold)
//package com.java2s; /*/*from w w w. ja v a 2s . c om*/ * This file is part of the LIRE project: http://www.semanticmetadata.net/lire * LIRE 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 2 of the License, or * (at your option) any later version. * * LIRE 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 LIRE; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * We kindly ask you to refer the any or one of the following publications in * any publication mentioning or employing Lire: * * Lux Mathias, Savvas A. Chatzichristofis. Lire: Lucene Image Retrieval ? * An Extensible Java CBIR Library. In proceedings of the 16th ACM International * Conference on Multimedia, pp. 1085-1088, Vancouver, Canada, 2008 * URL: http://doi.acm.org/10.1145/1459359.1459577 * * Lux Mathias. Content Based Image Retrieval with LIRE. In proceedings of the * 19th ACM International Conference on Multimedia, pp. 735-738, Scottsdale, * Arizona, USA, 2011 * URL: http://dl.acm.org/citation.cfm?id=2072432 * * Mathias Lux, Oge Marques. Visual Information Retrieval using Java and LIRE * Morgan & Claypool, 2013 * URL: http://www.morganclaypool.com/doi/abs/10.2200/S00468ED1V01Y201301ICR025 * * Copyright statement: * ==================== * (c) 2002-2013 by Mathias Lux (mathias@juggle.at) * http://www.semanticmetadata.net/lire, http://www.lire-project.net * * Updated: 11.07.13 09:32 */ import java.awt.image.BufferedImage; import java.awt.image.WritableRaster; public class Main { /** * Converts an image (RGB, RGBA, ... whatever) to a binary one based on given threshold * * @param image the image to convert. Remains untouched. * @param threshold the threshold in [0,255] * @return a new BufferedImage instance of TYPE_BYTE_GRAY with only 0'S and 255's */ public static BufferedImage thresholdImage(BufferedImage image, int threshold) { BufferedImage result = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_BYTE_GRAY); result.getGraphics().drawImage(image, 0, 0, null); WritableRaster raster = result.getRaster(); int[] pixels = new int[image.getWidth()]; for (int y = 0; y < image.getHeight(); y++) { raster.getPixels(0, y, image.getWidth(), 1, pixels); for (int i = 0; i < pixels.length; i++) { if (pixels[i] < threshold) pixels[i] = 0; else pixels[i] = 255; } raster.setPixels(0, y, image.getWidth(), 1, pixels); } return result; } }