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

public class ejemplo_neg3 implements PlugInFilter
{
ImagePlus imp;

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

public void run(ImageProcessor ip)
{

int w=ip.getWidth();
int n=ip.getHeight();
for(int i=0;i {
for(int j=0;j {
int p=ip.getPixel(i,j);
if(p<50)
{
p=0;
}
if(p>50)
{
p=255;
}
ip.putPixel(i,j,255-p);
}

}
}

}