/* * Gray8HorizVertContrast.java * * Created on August 27, 2006, 4:32, PM * * To change this template, choose Tools | Template Manager * and open the template in the editor. * * Copyright 2007 by Jon A. Webb * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser 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 Lesser General Public License for more details. * * You should have received a copy of the Lesser GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. * */ package jjil.algorithm; import jjil.core.Image; import jjil.core.Ladder; import jjil.core.PipelineStage; /** * Computes a simple measure of horizontal-vertical contrast. * The measure is the difference in variance * over a window of a given size measured horizontally and vertically. * The measure used is a linear combination of the horizontal and vertical * contrast, clamped between Byte.MIN_VALUE and Byte.MAX_VALUE. * @author webb */ public class Gray8HorizVertContrast extends PipelineStage { PipelineStage pipe; /** Creates a new instance of Gray8HorizVertContrast. Builds the pipeline * which computes the horizontal-vertical contrast measure. Result is * (nA * horizontal + nB * vertical) / nC. * @param nWindow the size of the window to compute contrast over. * @param nA factor to multiply horizontal contrast by * @param nB factor to multiply vertical contrast by * @param nC divisor */ public Gray8HorizVertContrast(int nWindow, int nA, int nB, int nC) { Gray8HorizVar ghv = new Gray8HorizVar(nWindow); Gray8VertVar gvv = new Gray8VertVar(nWindow); Gray16LinComb glc = new Gray16LinComb(nA, nB, nC); this.pipe = new Ladder(ghv, gvv, glc); } /** Apply the contrast measure to the input input image. * @param image the input Gray16Image * @throws jjil.core.Error if image is not a Gray16Image */ public void push(Image image) throws jjil.core.Error { this.pipe.push(image); super.setOutput(this.pipe.getFront()); } }