| Shadows |

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

    /** Implements the commands in the Process/Shadows submenu. */
    public class Shadows implements PlugInFilter {

        String arg;
        ImagePlus imp;

        public int setup(String arg, ImagePlus imp) {
            this.arg = arg;
            this.imp = imp;
            if (imp!=null && imp.getStackSize()>1 && arg.equals("demo"))
                {IJ.error("This demo does not work with stacks."); return DONE;}
            return IJ.setupDialog(imp, DOES_ALL+SUPPORTS_MASKING);
        }

        public void run(ImageProcessor ip) {
            if (arg.equals("demo")) {
                IJ.resetEscape();
                while (!IJ.escapePressed()) {
                    north(ip); imp.updateAndDraw(); ip.reset();
                    northeast(ip); imp.updateAndDraw(); ip.reset();
                    east(ip); imp.updateAndDraw(); ip.reset();
                    southeast(ip); imp.updateAndDraw(); ip.reset();
                    south(ip); imp.updateAndDraw(); ip.reset();
                    southwest(ip); imp.updateAndDraw(); ip.reset();
                    west(ip); imp.updateAndDraw(); ip.reset();
                    northwest(ip); imp.updateAndDraw(); ip.reset();
                }
            }
            else if (arg.equals("north")) north(ip);
            else if (arg.equals("northeast")) northeast(ip);
            else if (arg.equals("east")) east(ip);
            else if (arg.equals("southeast")) southeast(ip);
            else if (arg.equals("south")) south(ip);
            else if (arg.equals("southwest")) southwest(ip);
            else if (arg.equals("west")) west(ip);
            else if (arg.equals("northwest")) northwest(ip);

        }

            public void north(ImageProcessor ip) {
                int[] kernel = {1,2,1, 0,1,0,  -1,-2,-1};
                ip.convolve3x3(kernel);
            }

            public void south(ImageProcessor ip) {
                int[] kernel = {-1,-2,-1,  0,1,0,  1,2,1};
                ip.convolve3x3(kernel);
            }

            public void east(ImageProcessor ip) {
                int[] kernel = {-1,0,1,  -2,1,2,  -1,0,1};
                ip.convolve3x3(kernel);
            }

            public void west(ImageProcessor ip) {
                int[] kernel = {1,0,-1,  2,1,-2,  1,0,-1};
                ip.convolve3x3(kernel);
            }

            public void northwest(ImageProcessor ip) {
                int[] kernel = {2,1,0,  1,1,-1,  0,-1,-2};
                ip.convolve3x3(kernel);
            }

            public void southeast(ImageProcessor ip) {
                int[] kernel = {-2,-1,0,  -1,1,1,  0,1,2};
                ip.convolve3x3(kernel);
            }

            public void northeast(ImageProcessor ip) {
                int[] kernel = {0,1,2,  -1,1,1,  -2,-1,0};
                ip.convolve3x3(kernel);
            }

            public void southwest(ImageProcessor ip) {
                int[] kernel = {0,-1,-2,  1,1,-1,  2,1,0};
                ip.convolve3x3(kernel);
            }
    }

| Shadows |