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Image Tracking and Computer Vision Using Fourier Image Correlation

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23 Apr 2013CPOL15 min read 71.8K   17.2K   90  
How to teach a program to recognize something within a video stream.
///////////////////////////////////////////////////////////////////////////////
//
//  TrackingUI.cs
//
//  By Philip R. Braica (HoshiKata@aol.com, VeryMadSci@gmail.com)
//
//  Distributed under the The Code Project Open License (CPOL)
//  http://www.codeproject.com/info/cpol10.aspx
///////////////////////////////////////////////////////////////////////////////

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using OpenCvSharp;

namespace OpenCVDemo
{
    /// <summary>
    /// Demo UI for tracking with open CV.
    /// </summary>
    public partial class TrackingUI : UserControl
    {
        /// <summary>
        /// Constructor.
        /// </summary>
        public TrackingUI()
        {
            InitializeComponent();
            pictureBox1.MouseDown += new MouseEventHandler(pictureBox1_MouseDown);
            pictureBox1.MouseUp += new MouseEventHandler(pictureBox1_MouseUp);
            pictureBox1.MouseMove += new MouseEventHandler(pictureBox1_MouseMove);
            button2.Enabled = false;
            button3.Enabled = false;
            button4.Enabled = false;
            button5.Enabled = false;
            button6.Enabled = false;
            
        }

        /// <summary>
        /// Load video
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e)
        {
            timer1.Enabled = false;
            button7.Enabled = false;
            OpenFileDialog ofd = new OpenFileDialog();
            DialogResult dr = ofd.ShowDialog();
            if (dr != DialogResult.OK) return;

            if (m_cvCapture != null)
            {
                m_cvCapture.Dispose();
            }
            m_cvCapture = CvCapture.FromFile(ofd.FileName);
            m_videoFileName = ofd.FileName;

            // Hack to get first frame.
            timer1_Tick(this, new EventArgs());
            if (m_leftFront != null)
            {
                m_firstFrame = new Bitmap(m_leftFront);
            }

            // Start playing.
            timer1.Enabled = true;
            button7.Enabled = true;
            button2.Enabled = false;
            button4.Enabled = false;
            button5.Enabled = false;
            button6.Enabled = true;
            button3.Enabled = true;
        }

        #region Selecting the rectangle.
        /// <summary>
        /// Select rect.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button3_Click(object sender, EventArgs e)
        {
            timer1.Enabled = false;
            button7.Enabled = false;
            pictureBox1.Image = m_firstFrame;
            m_selectingRect = true;
        }

        /// <summary>
        /// Mouse up selected.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void pictureBox1_MouseUp(object sender, MouseEventArgs e)
        {
            if (!m_selectingRect) return;
            float x = e.X - pictureBox1.Left;
            float y = e.Y - pictureBox1.Top;
            float iw = pictureBox1.Image.Width;
            float ih = pictureBox1.Image.Height;
            float w = pictureBox1.Width;
            float h = pictureBox1.Height;
            int nx = (int)(x * iw / w);
            int ny = (int)(y * ih / h);
            int ox = m_selectedRect.Location.X;
            int oy = m_selectedRect.Location.Y;
            if (nx < ox)
            {
                if (ny < oy) m_selectedRect = new Rectangle(nx, ny, ox - nx, oy - ny);
                else m_selectedRect = new Rectangle(nx, oy, ox - nx, ny - oy);
            }
            else
            {
                if (ny < oy) m_selectedRect = new Rectangle(ox, ny, nx - ox, oy - ny);
                else m_selectedRect = new Rectangle(ox, oy, nx - ox, ny - oy);
            }
            m_selectingRect = false;
            if ((m_selectedRect.Width > 4) && (m_selectedRect.Height > 4))
            {
                button2.Enabled = true;
                button4.Enabled = true;
                button5.Enabled = true;
                button6.Enabled = true;
            }
        }

        /// <summary>
        /// Mouse moved.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void pictureBox1_MouseMove(object sender, MouseEventArgs e)
        {
            if (!m_selectingRect) return;
            float x = e.X - pictureBox1.Left;
            float y = e.Y - pictureBox1.Top;
            float iw = pictureBox1.Image.Width;
            float ih = pictureBox1.Image.Height;
            float w = pictureBox1.Width;
            float h = pictureBox1.Height;
            int nx = (int)(x * iw / w);
            int ny = (int)(y * ih / h);
            int ox = m_selectedRect.Location.X;
            int oy = m_selectedRect.Location.Y;
            if (nx < ox)
            {
                if (ny < oy) m_selectedRect = new Rectangle(nx, ny, ox - nx, oy - ny);
                else m_selectedRect = new Rectangle(nx, oy, ox - nx, ny - oy);
            }
            else
            {
                if (ny < oy) m_selectedRect = new Rectangle(ox, ny, nx - ox, oy - ny);
                else m_selectedRect = new Rectangle(ox, oy, nx - ox, ny - oy);
            }

            setupBuffers(m_firstFrame.Width, m_firstFrame.Height);

            using (Graphics g = Graphics.FromImage(m_leftBack))
            {
                g.DrawImage(m_firstFrame, 0, 0, m_leftBack.Width, m_leftBack.Height);
                using (Pen p = new Pen(Color.FromArgb(128, Color.Green), 4f))
                {
                    if (e.Button == System.Windows.Forms.MouseButtons.None)
                    {
                        Rectangle sp = new Rectangle(nx - 2, ny - 2, 4, 4);
                        g.DrawEllipse(p, sp);
                    }
                    else
                    {
                        g.DrawRectangle(p, m_selectedRect);
                    }
                }
            }
            pictureBox1.Image = m_leftBack;
        }

        /// <summary>
        /// Setup the image buffers.
        /// </summary>
        /// <param name="w"></param>
        /// <param name="h"></param>
        protected void setupBuffers(int w, int h)
        {
            bool doSetup = true;
            if (m_leftBack != null)
            {
                if ((m_leftBack.Width == w) || (m_leftBack.Height == h))
                {
                    doSetup = false;
                }
            }
            if (doSetup)
            {
                if (m_leftBack != null) m_leftBack.Dispose();
                if (m_rightBack != null) m_rightBack.Dispose();
                m_leftBack = new System.Drawing.Bitmap(w, h, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
                m_rightBack = new System.Drawing.Bitmap(w, h, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
            }
        }

        /// <summary>
        /// Down.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void pictureBox1_MouseDown(object sender, MouseEventArgs e)
        {
            if (!m_selectingRect) return; 
            float x = e.X - pictureBox1.Left;
            float y = e.Y - pictureBox1.Top;
            float iw = pictureBox1.Image.Width;
            float ih = pictureBox1.Image.Height;
            float w = pictureBox1.Width;
            float h = pictureBox1.Height;

            m_selectedRect.Location = new Point((int)(x * iw / w), (int)(y * ih / h));
        }
        #endregion

        /// <summary>
        /// Learn.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button2_Click(object sender, EventArgs e)
        {
            timer1.Enabled = false;
            button7.Enabled = false;
            if (m_cvCapture != null)
            {
                m_cvCapture.Dispose();
            }
            m_cvCapture = CvCapture.FromFile(m_videoFileName);
            m_learning = true;
            if (m_learn == null)
            {
                m_learn = new Tracker();
                m_learn.Font = this.Font;
            }
            m_learn.Reset();
            if (m_cvVideoWriter != null)
            {
                m_cvVideoWriter.Dispose();
                m_cvVideoWriter = null;
            }
            m_logging = false;
            timer1.Enabled = true;
            button7.Enabled = true;
        }

        /// <summary>
        /// Learn and save.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button4_Click(object sender, EventArgs e)
        {
            timer1.Enabled = false;
            button7.Enabled = false;
            if (m_cvCapture != null)
            {
                m_cvCapture.Dispose();
            }
            m_cvCapture = CvCapture.FromFile(m_videoFileName);
            m_learning = true;
            SaveFileDialog sfd = new SaveFileDialog();
            DialogResult dr = sfd.ShowDialog();
            if (dr != DialogResult.OK)
            {
                return;
            }
            if (m_cvVideoWriter != null)
            {
                m_cvVideoWriter.Dispose();
                m_cvVideoWriter = null;
            }
            m_logging = false;

            m_cvVideoWriter = new CvVideoWriter(sfd.FileName,
                FourCC.DIB, // IYUB, MSVC, DIB, CVID are supported.
                10,
                new CvSize(m_rightBack.Width, m_rightBack.Height));
            m_learn.Reset();
            timer1.Enabled = true;
            button7.Enabled = true;
        }

        /// <summary>
        /// Learn and log.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button5_Click(object sender, EventArgs e)
        {
            timer1.Enabled = false;
            button7.Enabled = false;
            if (m_cvCapture != null)
            {
                m_cvCapture.Dispose();
            }
            m_cvCapture = CvCapture.FromFile(m_videoFileName);
            m_learning = true;
            if (m_learn == null)
            {
                m_learn = new Tracker();
            }
            m_learn.Reset();

            SaveFileDialog sfd = new SaveFileDialog();
            DialogResult dr = sfd.ShowDialog();
            if (dr != DialogResult.OK)
            {
                return;
            }
            if (m_cvVideoWriter != null)
            {
                m_cvVideoWriter.Dispose();
                m_cvVideoWriter = null;
            }
            m_logFile = sfd.FileName;
            m_logging = true;
            timer1.Enabled = true;
            button7.Enabled = true;
        }

        #region Protected data.

        /// <summary>
        /// Log file.
        /// </summary>
        protected string m_logFile = "";
        
        /// <summary>
        /// Logging.
        /// </summary>
        protected bool m_logging = false;

        /// <summary>
        /// The selected rectangle.
        /// </summary>
        protected Rectangle m_selectedRect = new Rectangle(0, 0, 0, 0);

        /// <summary>
        /// We are selecting a rectangle.
        /// </summary>
        protected bool m_selectingRect = false;

        /// <summary>
        /// Capture device.
        /// </summary>
        protected CvCapture m_cvCapture = null;

        /// <summary>
        /// Video writer.
        /// </summary>
        protected CvVideoWriter m_cvVideoWriter = null;

        /// <summary>
        /// The name of the last video file loaded.
        /// </summary>
        protected string m_videoFileName = "";

        /// <summary>
        /// Learning flag.
        /// </summary>
        protected bool m_learning = false;

        /// <summary>
        /// First frame.
        /// </summary>
        protected Bitmap m_firstFrame = null;

        /// <summary>
        /// Left back buffer.
        /// </summary>
        protected Bitmap m_leftBack = null;

        /// <summary>
        /// Right back buffer.
        /// </summary>
        protected Bitmap m_rightBack = null;

        /// <summary>
        /// Left front buffer.
        /// </summary>
        protected Bitmap m_leftFront = null;

        /// <summary>
        /// Right front buffer.
        /// </summary>
        protected Bitmap m_rightFront = null;

        /// <summary>
        /// Learning object.
        /// </summary>
        protected Tracker m_learn = null;
        #endregion

        /// <summary>
        /// Learn.
        /// </summary>
        /// <param name="img"></param>
        protected void learn(IplImage img, Bitmap markup)
        {
            if (m_learn == null)
            {
                m_learn = new Tracker();
            }
            if ((m_selectedRect.Width > 3) && (m_selectedRect.Height > 3))
            {
                m_learn.Learn(img, markup, m_selectedRect, m_logging);
            }
        }

        /// <summary>
        /// Save a frame.
        /// </summary>
        /// <param name="img"></param>
        protected void saveFrame(Bitmap img)
        {
            if (img == null) return;
            CvVideoWriter cvw = m_cvVideoWriter;
            if (cvw == null) return;
            if (cvw.IsDisposed) return;
            IplImage ipltmp = IplImage.FromBitmap(img);
            cvw.WriteFrame(ipltmp);
            ipltmp.Dispose();
        }


        /// <summary>
        /// Timer, grabs an input frame if there is one,
        /// triggers processing and handles double buffering as needed.
        /// 
        /// Also uses simple double buffering.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void timer1_Tick(object sender, EventArgs e)
        {
            // This is demo code, so not everything is thread safe but
            // Since the obvious most annoying race is m_cvCapture changing,
            // This made sence to guard against.
            //
            // Grab a local copy of the reference then act on it.
            CvCapture threadSafeCapture = m_cvCapture;
            if (threadSafeCapture == null) return;
            threadSafeCapture.GrabFrame();
            IplImage img = threadSafeCapture.RetrieveFrame();

            // Video is done.
            if ((img == null) || (threadSafeCapture.PosFrames == threadSafeCapture.FrameCount))
            {
                m_cvCapture.Dispose();
                m_cvCapture = null;
                timer1.Enabled = false;
                button7.Enabled = false;
                if (m_cvVideoWriter != null)
                {
                    m_cvVideoWriter.Dispose();
                    m_cvVideoWriter = null;
                }
                if (m_logging)
                {
                    using (System.IO.StreamWriter sw = new System.IO.StreamWriter(m_logFile))
                    {
                        sw.Write(m_learn.MakeLogReport());
                        sw.Close();
                    }
                }
                return;
            }

            // Make sure the bitmap buffers are the right size.
            setupBuffers(img.Width, img.Height);

            // Draw the raw frame to the left.
            System.Drawing.Bitmap tmp = img.ToBitmap();
            using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(m_leftBack))
            {
                g.DrawImage(tmp, 0, 0, m_leftBack.Width, m_leftBack.Height);
            }
            using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(m_rightBack))
            {
                g.DrawImage(tmp, 0, 0, m_rightBack.Width, m_rightBack.Height);
            }

            // Learn if learning.
            if (m_learning)
            {
                learn(img, m_rightBack);
            }

            // Save if saving.
            if (m_cvVideoWriter != null)
            {
                saveFrame(m_rightBack);
            }
              
            // Dispose of the temp. bitmap.
            tmp.Dispose();


            // Swap left and right buffers and display.
            System.Drawing.Bitmap btmp = m_leftBack;
            m_leftBack = m_leftFront;
            m_leftFront = btmp;
            btmp = m_rightBack;
            m_rightBack = m_rightFront;
            m_rightFront = btmp;
            pictureBox1.Image = m_leftFront;
            pictureBox2.Image = m_rightFront;
        }

        /// <summary>
        /// Save a feature.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button6_Click(object sender, EventArgs e)
        {
            SaveFileDialog sfd = new SaveFileDialog();
            DialogResult dr = sfd.ShowDialog();
            if ((dr == DialogResult.OK) || (dr == DialogResult.Yes))
            {
                m_learn.SaveFeature(sfd.FileName, textBox1.Text);
            }
        }

        /// <summary>
        /// Stop the timer.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button7_Click(object sender, EventArgs e)
        {
            timer1.Enabled = false;
        }



    }
}

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License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Technical Lead
United States United States
Phil is a Principal Software developer focusing on weird yet practical algorithms that run the gamut of embedded and desktop (PID loops, Kalman filters, FFTs, client-server SOAP bindings, ASIC design, communication protocols, game engines, robotics).

In his personal life he is a part time mad scientist, full time dad, and studies small circle jujitsu, plays guitar and piano.

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