Computer Vision Applications with C# - Part II

��using System;

using System.Drawing;

using System.Drawing.Imaging;

using System.Collections.Generic;

using System.Windows.Forms;



using ImageProcessor;

using UIGraphic;



namespace Tracker

{

	/// <summary>

	/// Summary description for Centroid.

	/// </summary>

	public class Centroid : ITracker

	{	

        public Centroid()

        {

            _imgProc = new Processor(); //create image processor

        }



        public void CreateTargetModel(Bitmap bitmap, int binCountCh1, int binCountCh2, int binCountCh3, Window targetRoi, Window searchRoi)

		{

            _targetRoi = targetRoi;

            _searchRoi = searchRoi;

            

            //Get the required section

            Bitmap cropped = GetImageSection(bitmap, targetRoi);



            //create target histogram

            _hist = _imgProc.Create1DHistogram(cropped, binCountCh1 , binCountCh2, binCountCh3);

		}

                       

		public void Track(Bitmap bitmap, out Window targetRoi, out Window searchRoi)

		{

            //get the required image section

            Bitmap cropped = GetImageSection(bitmap, _searchRoi);

            

            //create backprojection image

            _processedImage = _imgProc.CreateBackprojectionImage(bitmap, _hist, _searchRoi.RegionOfInterest);



            //Find moments of the binary image which was selected

            Bitmap bin = _processedImage.Clone(_searchRoi.RegionOfInterest, _processedImage.PixelFormat);

            _moment = new Moment(bin);



            //Find the centroid in the whole image

            int centreX = 0;

            centreX = _targetRoi.RegionOfInterest.X + (int)(_moment.FirstMomentX / _moment.ZerothMoment);

            int centreY = 0;

            centreY = _targetRoi.RegionOfInterest.Y + (int)(_moment.FirstMomentY / _moment.ZerothMoment);



            //add information

            SaveInformation(centreX, centreY);

            

            //check validity

            if (centreX > 0 && centreY > 0)

            {



                //Move the roi & search window to the new centroid

                _targetRoi.Offset(centreX - _targetRoi.CentreX, centreY - _targetRoi.CentreY);

                _searchRoi.Offset(centreX - _searchRoi.CentreX, centreY - _searchRoi.CentreY);



                _processedImage = Drawer.DrawMoment(_processedImage, _moment, new Point(centreX, centreY));



               } 

            

            targetRoi = _targetRoi;

            searchRoi = _searchRoi;

            

		}



        public Bitmap ProcessedImage

        {

            get { return _processedImage; }

        }



        public Dictionary<string, string> Information

        {

            get { return _moment.Information; }

        }



        private void SaveInformation(int centreX, int centreY)

        {

            _moment.Information.Add("Centroid", "(" + centreX.ToString() + ", " + centreY.ToString() + ")");            

        }



        private Bitmap GetImageSection(Bitmap bmp, Window roi)

        {

            roi.EnsureLimits(); //make sure it is not out of the picture

            return bmp.Clone(roi.RegionOfInterest, bmp.PixelFormat); //select the section            

        }



        private Processor _imgProc = null;

        private Histogram _hist = null;

        private Bitmap _processedImage = null;

        private Window _targetRoi;

        private Window _searchRoi;

        private Moment _moment = null;

    }

}