extract points position from image

ball.png

MainView.java

package com.example.zyj.myapplication;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.View;

public class MainView extends View {
    private static final String TAG = MainView.class.getName();

    private Bitmap mBmpBall;

    public MainView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mBmpBall = BitmapFactory.decodeResource(getResources(), R.drawable.ball);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.drawBitmap(mBmpBall, 0, 0, null);
        canvas.drawBitmap(procBall(), 350, 350, null);
    }

    private Bitmap procBall() {
        Bitmap tmpBmp = mBmpBall.copy(Bitmap.Config.ARGB_8888, true);
        Bitmap bmp = Bitmap.createBitmap(mBmpBall.getWidth(), mBmpBall.getHeight(), Bitmap.Config.ARGB_8888);

        Canvas canvas = new Canvas(bmp);
        Paint paint = new Paint();
        paint.setColor(Color.RED);
        paint.setStrokeWidth(4);
        paint.setAntiAlias(true);

        for (int y = 0; y < mBmpBall.getHeight(); y++) {
            for (int x = 0; x < mBmpBall.getWidth(); x++) {
                if (isWhiteColor(tmpBmp, x, y)) {
                    Point point = getPoint(tmpBmp, x, y);
                    canvas.drawPoint(point.x, point.y, paint);
                }
            }
        }
        return bmp;
    }

    private Point getPoint(Bitmap bmp, int x, int y) {
        Rect rect = new Rect(x, y, x, y);
        bmp.setPixel(x, y, Color.BLACK);
        recursioGetRect(bmp, rect, x, y);
        return new Point(rect.centerX(), rect.centerY());
    }

    private void recursioGetRect(Bitmap bmp, Rect rect, int x, int y) {
        _recursionGetRegion(bmp, rect, x - 1, y);   // left
        _recursionGetRegion(bmp, rect, x, y + 1);   // top
        _recursionGetRegion(bmp, rect, x + 1, y);   // right
        _recursionGetRegion(bmp, rect, x, y - 1);   // bottom
    }

    private void _recursionGetRegion(Bitmap bmp, Rect rect, int x, int y) {
        if (false == new Rect(0, 0, bmp.getWidth(), bmp.getHeight()).contains(x, y))
            return;
        if (false == isWhiteColor(bmp, x, y))
            return;
        bmp.setPixel(x, y, Color.BLACK);
        rect.union(x, y);
        recursioGetRect(bmp, rect, x, y);
    }

    private boolean isWhiteColor(Bitmap bmp, int x, int y) {
        int color = bmp.getPixel(x, y);
        if (0xff000000 != color)
            return true;
        return false;
    }
}