Filtro Umbralización

import ij.*;
import ij.process.*;
import ij.gui.*;
import java.awt.*;
import ij.plugin.filter.*;

public class Filter_Umbralizacion implements PlugInFilter
{
ImagePlus imp;

public int setup(String arg, ImagePlus imp)
{
this.imp = imp;
return DOES_8G;
}

public void run(ImageProcessor ip)
{
int w=ip.getWidth();
int n=ip.getHeight();
for(int i =0; i < w;i++)
{
for(int j= 0; j < n;j++)
{
int p =ip.getPixel(i,j);
//p = (int)(p*2+50);
if (p < 50){
p=0;
}else if(p > =50){
p=255;
}
ip.putPixel(i,j,p);
}
}
}

}