package ij.process;
//import ij.*;
import java.awt.*;

/** This class processes binary images. */
public class BinaryProcessor extends ByteProcessor {

    private ByteProcessor parent;
    
    /** Creates a BinaryProcessor from a ByteProcessor. The ByteProcessor
        must contain a binary image (pixels values are either 0 or 255).
        Backgound is assumed to be white. */
    public BinaryProcessor(ByteProcessor ip) {
        super(ip.getWidth(), ip.getHeight(), (byte[])ip.getPixels(), ip.getColorModel());
        setRoi(ip.getRoi());
        parent = ip;
    }

    static final int OUTLINE=0;
    
    void process(int type, int count) {
        int p1, p2, p3, p4, p5, p6, p7, p8, p9;
        int inc = roiHeight/25;
        if (inc<1) inc = 1;
        int bgColor = 255;
        if (parent.isInvertedLut())
            bgColor = 0;

        byte[] pixels2 = (byte[])parent.getPixelsCopy();
        int offset, v=0, sum;
        int rowOffset = width;
        for (int y=yMin; y<=yMax; y++) {
            offset = xMin + y * width;
            p2 = pixels2[offset-rowOffset-1]&0xff;
            p3 = pixels2[offset-rowOffset]&0xff;
            p5 = pixels2[offset-1]&0xff;
            p6 = pixels2[offset]&0xff;
            p8 = pixels2[offset+rowOffset-1]&0xff;
            p9 = pixels2[offset+rowOffset]&0xff;

            for (int x=xMin; x<=xMax; x++) {
                p1 = p2; p2 = p3;
                p3 = pixels2[offset-rowOffset+1]&0xff;
                p4 = p5; p5 = p6;
                p6 = pixels2[offset+1]&0xff;
                p7 = p8; p8 = p9;
                p9 = pixels2[offset+rowOffset+1]&0xff;

                switch (type) {
                    case OUTLINE:
                        v = p5;
                        if (v!=bgColor) {
                            if (!(p1==bgColor || p2==bgColor || p3==bgColor || p4==bgColor
                                || p6==bgColor || p7==bgColor || p8==bgColor || p9==bgColor))
                                    v = bgColor;
                        }
                        break;
                }
                
                pixels[offset++] = (byte)v;
            }
            if (y%inc==0)
                parent.showProgress((double)(y-roiY)/roiHeight);
        }
        parent.hideProgress();
    }

    /** Uses a lookup table to repeatably removes pixels from the
        edges of objects in a binary image, reducing them to single
        pixel wide skeletons. Based on an a thinning algorithm by
        by Zhang and Suen (CACM, March 1984, 236-239). There is
        an entry in the table for each of the 256 possible 3x3 neighborhood
        configurations. An entry of '1' means delete pixel on first pass, '2' means
        delete pixel on second pass, and '3' means delete on either pass. A graphical
        representation of the 256 neighborhoods indexed by the table is available
        at "http://rsb.info.nih.gov/ij/images/skeletonize-table.gif".
    */
    public void  skeletonize() {
        int[] table  =
                //0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0,1
                 {0,0,0,1,0,0,1,3,0,0,3,1,1,0,1,3,0,0,0,0,0,0,0,0,2,0,2,0,3,0,3,3,
                  0,0,0,0,0,0,0,0,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,0,0,0,3,0,2,2,
                  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
                  2,0,0,0,0,0,0,0,2,0,0,0,2,0,0,0,3,0,0,0,0,0,0,0,3,0,0,0,3,0,2,0,
                  0,0,3,1,0,0,1,3,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,
                  3,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
                  2,3,1,3,0,0,1,3,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
                  2,3,0,1,0,0,0,1,0,0,0,0,0,0,0,0,3,3,0,1,0,0,0,0,2,2,0,0,2,0,0,0};
        int pass = 0;
        int pixelsRemoved;
        //ImageStack movie=null;
        //boolean debug = IJ.altKeyDown();
        //if (debug) movie = new ImageStack(width, height);
        do {
            setColor(Color.white);
            if (roiX==0) {moveTo(0,0); lineTo(0,height-1);}
            if (roiY==0) {moveTo(0,0); lineTo(width-1,0);}
            if (roiWidth==width) {moveTo(width-1,0); lineTo(width-1,height-1);}
            if (roiHeight==height) {moveTo(0,height-1); lineTo(width/*-1*/,height-1);}
            snapshot();
            //if (debug) movie.addSlice(""+pass, duplicate());
            pixelsRemoved = thin(pass++, table);
            snapshot();
            //if (debug) movie.addSlice(""+pass, duplicate());
            pixelsRemoved = thin(pass++, table);
            //ij.IJ.write(pass+" "+pixelsRemoved);
        } while (pixelsRemoved>0);
        //if (debug) new ImagePlus("Skel Movie", movie).show();
    }

    int thin(int pass, int[] table) {
        int p1, p2, p3, p4, p5, p6, p7, p8, p9;
        int inc = roiHeight/25;
        if (inc<1) inc = 1;
        int bgColor = 255;
        if (parent.isInvertedLut())
            bgColor = 0;
            
        byte[] pixels2 = (byte[])getPixelsCopy();
        int v, index, code;
        int offset, rowOffset = width;
        int pixelsRemoved = 0;
        int count = 100;
        for (int y=yMin; y<=yMax; y++) {
            offset = xMin + y * width;
            for (int x=xMin; x<=xMax; x++) {
                p5 = pixels2[offset]&0xff;
                v = p5;
                if (v!=bgColor) {
                    p1 = pixels2[offset-rowOffset-1]&0xff;
                    p2 = pixels2[offset-rowOffset]&0xff;
                    p3 = pixels2[offset-rowOffset+1]&0xff;
                    p4 = pixels2[offset-1]&0xff;
                    p6 = pixels2[offset+1]&0xff;
                    p7 = pixels2[offset+rowOffset-1]&0xff;
                    p8 = pixels2[offset+rowOffset]&0xff;
                    p9 = pixels2[offset+rowOffset+1]&0xff;
                    index = 0;
                    if (p1!=bgColor) index |= 1;
                    if (p2!=bgColor) index |= 2;
                    if (p3!=bgColor) index |= 4;
                    if (p6!=bgColor) index |= 8;
                    if (p9!=bgColor) index |= 16;
                    if (p8!=bgColor) index |= 32;
                    if (p7!=bgColor) index |= 64;
                    if (p4!=bgColor) index |= 128;
                    code = table[index];
                    if ((pass&1)==1) { //odd pass
                        if (code==2 || code==3) {
                            v = bgColor;
                            pixelsRemoved++;
                        }
                    } else { //even pass
                        if (code==1 || code==3) {
                            v = bgColor;
                            pixelsRemoved++;
                        }
                    }
                }
                pixels[offset++] = (byte)v;
            }
            if (y%inc==0)
                showProgress((double)(y-roiY)/roiHeight);
        }
        hideProgress();
        return pixelsRemoved;
    }
    
    public void outline() {
        process(OUTLINE, 0);
    }
    
}