/*
* Gray8Threshold.java
*
* Created on September 9, 2006, 10:25 AM
*
* 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.Error;
import jjil.core.Gray8Image;
import jjil.core.Image;
import jjil.core.PipelineStage;
/**
* Threshold. Output is a Gray8Image with values less than threshold
* set to Byte.MAX_VALUE, below threshold set to Byte.MIN_VALUE if
* bWithin is true, opposite if bWithin is false.
* @author webb
*/
public class Gray8Threshold extends PipelineStage {
boolean bWithin;
int nThreshold;
/**
* Creates a new instance of Gray8Threshold
* @param nThreshold threshold value.
* @param bWithin direction of threshold. If true then
* output is true (Byte.MAX_VALUE) iff < threshold.
*/
public Gray8Threshold(int nThreshold, boolean bWithin) {
this.nThreshold = nThreshold;
this.bWithin = bWithin;
}
/** Threshold gray image. Output is Byte.MAX_VALUE over threshold,
* Byte.MIN_VALUE under.
*
* @param image the input image (and output)
* @throws jjil.core.Error if the image is not a gray 8-bit
* image.
*/
public void push(Image image)
throws jjil.core.Error
{
if (!(image instanceof Gray8Image)) {
throw new Error(
Error.PACKAGE.ALGORITHM,
ErrorCodes.IMAGE_NOT_GRAY8IMAGE,
image.toString(),
null,
null);
}
Gray8Image gray = (Gray8Image) image;
byte[] data = gray.getData();
for (int i=0; i<data.length; i++) {
data[i] = (((data[i]) < this.nThreshold)==this.bWithin) ?
Byte.MAX_VALUE : Byte.MIN_VALUE;
}
super.setOutput(image);
}
/**
*
* @return String describing class instance.
*/
public String toString() {
return super.toString() + "(" + this.nThreshold + ")"; //$NON-NLS-1$ //$NON-NLS-2$
}
}