How to implement face detection in C#

using System;
using System.Windows.Forms;
using System.Drawing;
using Ozeki.Camera;
using Ozeki.Media;
using Ozeki.Vision;

namespace FaceDetection_WF
{
    public partial class MainForm : Form
    {
        private OzekiCamera _camera;
        private MediaConnector _connector;
        private CameraURLBuilderWF _myCameraUrlBuilder;
        private ImageProcesserHandler _imageProcesserHandler;
        private IFaceDetector _faceDetector;
        private FrameCapture _frameCapture;
        private DrawingImageProvider _originalImageProvider;
        private DrawingImageProvider _processedImageProvider;

        public MainForm()
        {
            InitializeComponent();
        }

        void MainForm_Load(object sender, EventArgs e)
        {
            Init();

            SetVideoViewers();

            InitDetectorFields();
        }

        void Init()
        {
            _frameCapture = new FrameCapture();
            _frameCapture.SetInterval(5);
            _myCameraUrlBuilder = new CameraURLBuilderWF();
            _connector = new MediaConnector();
            _originalImageProvider = new DrawingImageProvider();
            _processedImageProvider = new DrawingImageProvider();

            _faceDetector = ImageProcesserFactory.CreateFaceDetector();

            _imageProcesserHandler = new ImageProcesserHandler();
            _imageProcesserHandler.AddProcesser(_faceDetector);
        }

        void SetVideoViewers()
        {
            OriginalViewer.SetImageProvider(_originalImageProvider);
            ProcessedViewer.SetImageProvider(_processedImageProvider);
        }

        void InitDetectorFields()
        {
            InvokeGuiThread(() =>
            {
                tbMinSizeWidth.Text = _faceDetector.MinSize.Width.ToString();
                tbMaxSizeWidth.Text = _faceDetector.MaxSize.Width.ToString();
                tbMinSizeHeight.Text = _faceDetector.MinSize.Height.ToString();
                tbMaxSizeHeight.Text = _faceDetector.MaxSize.Height.ToString();
            });
        }

        void ConnectCam()
        {
            _connector.Connect(_camera.VideoChannel, _originalImageProvider);
            _connector.Connect(_camera.VideoChannel, _frameCapture);
            _connector.Connect(_frameCapture, _imageProcesserHandler);
            _connector.Connect(_imageProcesserHandler, _processedImageProvider);
        }

        void Start()
        {
            OriginalViewer.Start();
            ProcessedViewer.Start();

            _frameCapture.Start();
            _camera.Start();
            _imageProcesserHandler.Start();
        }

        void InvokeGuiThread(Action action)
        {
            BeginInvoke(action);
        }

        private void button_Compose_Click(object sender, EventArgs e)
        {
            var result = _myCameraUrlBuilder.ShowDialog();

            if (result != DialogResult.OK) return;

            tb_cameraUrl.Text = _myCameraUrlBuilder.CameraURL;

            button_Connect.Enabled = true;
        }

        private void button_Connect_Click(object sender, EventArgs e)
        {
            if (_camera != null)
            {
                _camera.CameraStateChanged -= _camera_CameraStateChanged;
                _camera.Disconnect();
                _connector.Disconnect(_camera.VideoChannel, _processedImageProvider);
                _connector.Disconnect(_camera.VideoChannel, _originalImageProvider);
                _camera.Dispose();
                _camera = null;
            }

            _camera = new OzekiCamera(_myCameraUrlBuilder.CameraURL);
            _camera.CameraStateChanged += _camera_CameraStateChanged;
            button_Connect.Enabled = false;
            ConnectCam();
            Start();
        }

        private void _camera_CameraStateChanged(object sender, CameraStateEventArgs e)
        {
            InvokeGuiThread(() =>
            {
                if (e.State == CameraState.Streaming)
                    button_Disconnect.Enabled = true;

                if (e.State == CameraState.Disconnected)
                {
                    button_Connect.Enabled = true;
                    button_Disconnect.Enabled = false;
                }
            });

            InvokeGuiThread(() =>
            {
                stateLabel.Text = e.State.ToString();
            });
        }

        private void button_Disconnect_Click(object sender, EventArgs e)
        {
            if (_camera == null) return;

            _camera.Disconnect();
            _connector.Disconnect(_camera.VideoChannel, _originalImageProvider);
            _connector.Disconnect(_camera.VideoChannel, _processedImageProvider);

            _camera = null;
        }

        private void buttonSetFace_Click(object sender, EventArgs e)
        {
            InvokeGuiThread(() =>
            {
                _faceDetector.MinSize = new Size(Int32.Parse(tbMinSizeWidth.Text), Int32.Parse(tbMinSizeHeight.Text));
                _faceDetector.MaxSize = new Size(Int32.Parse(tbMaxSizeWidth.Text), Int32.Parse(tbMaxSizeHeight.Text));
            });
        }
    }
}
		

namespace FaceDetection_WF
{
    partial class MainForm
    {
        private System.ComponentModel.IContainer components = null;

        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        private void InitializeComponent()
        {
            this.label1 = new System.Windows.Forms.Label();
            this.label2 = new System.Windows.Forms.Label();
            this.OriginalViewer = new Ozeki.Media.VideoViewerWF();
            this.ProcessedViewer = new Ozeki.Media.VideoViewerWF();
            this.groupBox5 = new System.Windows.Forms.GroupBox();
            this.stateLabel = new System.Windows.Forms.Label();
            this.label14 = new System.Windows.Forms.Label();
            this.button_Connect = new System.Windows.Forms.Button();
            this.button_Disconnect = new System.Windows.Forms.Button();
            this.tb_cameraUrl = new System.Windows.Forms.TextBox();
            this.label13 = new System.Windows.Forms.Label();
            this.button_Compose = new System.Windows.Forms.Button();
            this.groupBox3 = new System.Windows.Forms.GroupBox();
            this.tbMaxSizeHeight = new System.Windows.Forms.TextBox();
            this.label10 = new System.Windows.Forms.Label();
            this.label9 = new System.Windows.Forms.Label();
            this.tbMinSizeHeight = new System.Windows.Forms.TextBox();
            this.label8 = new System.Windows.Forms.Label();
            this.label7 = new System.Windows.Forms.Label();
            this.buttonSetFace = new System.Windows.Forms.Button();
            this.tbMaxSizeWidth = new System.Windows.Forms.TextBox();
            this.label6 = new System.Windows.Forms.Label();
            this.tbMinSizeWidth = new System.Windows.Forms.TextBox();
            this.label5 = new System.Windows.Forms.Label();
            this.groupBox5.SuspendLayout();
            this.groupBox3.SuspendLayout();
            this.SuspendLayout();
 
            this.label1.AutoSize = true;
            this.label1.Font = new System.Drawing.Font("Microsoft Sans Serif", 8.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(238)));
            this.label1.Location = new System.Drawing.Point(7, 399);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(87, 13);
            this.label1.TabIndex = 0;
            this.label1.Text = "Original image";

            this.label2.AutoSize = true;
            this.label2.Font = new System.Drawing.Font("Microsoft Sans Serif", 8.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(238)));
            this.label2.Location = new System.Drawing.Point(348, 399);
            this.label2.Name = "label2";
            this.label2.Size = new System.Drawing.Size(103, 13);
            this.label2.TabIndex = 1;
            this.label2.Text = "Processed image";

            this.OriginalViewer.BackColor = System.Drawing.Color.Black;
            this.OriginalViewer.FlipMode = Ozeki.Media.FlipMode.None;
            this.OriginalViewer.FrameStretch = Ozeki.Media.FrameStretch.Uniform;
            this.OriginalViewer.FullScreenEnabled = true;
            this.OriginalViewer.Location = new System.Drawing.Point(10, 143);
            this.OriginalViewer.Name = "OriginalViewer";
            this.OriginalViewer.RotateAngle = 0;
            this.OriginalViewer.Size = new System.Drawing.Size(330, 240);
            this.OriginalViewer.TabIndex = 17;
            this.OriginalViewer.Text = "videoViewerWF1";

            this.ProcessedViewer.BackColor = System.Drawing.Color.Black;
            this.ProcessedViewer.FlipMode = Ozeki.Media.FlipMode.None;
            this.ProcessedViewer.FrameStretch = Ozeki.Media.FrameStretch.Uniform;
            this.ProcessedViewer.FullScreenEnabled = true;
            this.ProcessedViewer.Location = new System.Drawing.Point(351, 143);
            this.ProcessedViewer.Name = "ProcessedViewer";
            this.ProcessedViewer.RotateAngle = 0;
            this.ProcessedViewer.Size = new System.Drawing.Size(320, 240);
            this.ProcessedViewer.TabIndex = 18;
            this.ProcessedViewer.Text = "videoViewerWF1";

            this.groupBox5.Controls.Add(this.stateLabel);
            this.groupBox5.Controls.Add(this.label14);
            this.groupBox5.Controls.Add(this.button_Connect);
            this.groupBox5.Controls.Add(this.button_Disconnect);
            this.groupBox5.Controls.Add(this.tb_cameraUrl);
            this.groupBox5.Controls.Add(this.label13);
            this.groupBox5.Controls.Add(this.button_Compose);
            this.groupBox5.Location = new System.Drawing.Point(12, 12);
            this.groupBox5.Name = "groupBox5";
            this.groupBox5.Size = new System.Drawing.Size(328, 125);
            this.groupBox5.TabIndex = 21;
            this.groupBox5.TabStop = false;
            this.groupBox5.Text = "Connect";

            this.stateLabel.AutoSize = true;
            this.stateLabel.Location = new System.Drawing.Point(80, 72);
            this.stateLabel.Name = "stateLabel";
            this.stateLabel.Size = new System.Drawing.Size(0, 13);
            this.stateLabel.TabIndex = 24;

            this.label14.AutoSize = true;
            this.label14.Location = new System.Drawing.Point(39, 72);
            this.label14.Name = "label14";
            this.label14.Size = new System.Drawing.Size(35, 13);
            this.label14.TabIndex = 23;
            this.label14.Text = "State:";

            this.button_Connect.Enabled = false;
            this.button_Connect.Font = new System.Drawing.Font("Microsoft Sans Serif", 8.5F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(238)));
            this.button_Connect.ForeColor = System.Drawing.Color.Black;
            this.button_Connect.Location = new System.Drawing.Point(83, 39);
            this.button_Connect.Name = "button_Connect";
            this.button_Connect.Size = new System.Drawing.Size(69, 23);
            this.button_Connect.TabIndex = 18;
            this.button_Connect.Text = "Connect";
            this.button_Connect.UseVisualStyleBackColor = true;
            this.button_Connect.Click += new System.EventHandler(this.button_Connect_Click);

            this.button_Disconnect.Enabled = false;
            this.button_Disconnect.Location = new System.Drawing.Point(180, 39);
            this.button_Disconnect.Name = "button_Disconnect";
            this.button_Disconnect.Size = new System.Drawing.Size(69, 23);
            this.button_Disconnect.TabIndex = 22;
            this.button_Disconnect.Text = "Disconnect";
            this.button_Disconnect.UseVisualStyleBackColor = true;
            this.button_Disconnect.Click += new System.EventHandler(this.button_Disconnect_Click);

            this.tb_cameraUrl.Location = new System.Drawing.Point(83, 13);
            this.tb_cameraUrl.Name = "tb_cameraUrl";
            this.tb_cameraUrl.ReadOnly = true;
            this.tb_cameraUrl.Size = new System.Drawing.Size(166, 20);
            this.tb_cameraUrl.TabIndex = 21;

            this.label13.AutoSize = true;
            this.label13.Location = new System.Drawing.Point(6, 16);
            this.label13.Name = "label13";
            this.label13.Size = new System.Drawing.Size(71, 13);
            this.label13.TabIndex = 20;
            this.label13.Text = "Camera URL:";

            this.button_Compose.Location = new System.Drawing.Point(253, 11);
            this.button_Compose.Name = "button_Compose";
            this.button_Compose.Size = new System.Drawing.Size(69, 23);
            this.button_Compose.TabIndex = 19;
            this.button_Compose.Text = "Compose";
            this.button_Compose.UseVisualStyleBackColor = true;
            this.button_Compose.Click += new System.EventHandler(this.button_Compose_Click);

            this.groupBox3.Controls.Add(this.tbMaxSizeHeight);
            this.groupBox3.Controls.Add(this.label10);
            this.groupBox3.Controls.Add(this.label9);
            this.groupBox3.Controls.Add(this.tbMinSizeHeight);
            this.groupBox3.Controls.Add(this.label8);
            this.groupBox3.Controls.Add(this.label7);
            this.groupBox3.Controls.Add(this.buttonSetFace);
            this.groupBox3.Controls.Add(this.tbMaxSizeWidth);
            this.groupBox3.Controls.Add(this.label6);
            this.groupBox3.Controls.Add(this.tbMinSizeWidth);
            this.groupBox3.Controls.Add(this.label5);
            this.groupBox3.Location = new System.Drawing.Point(351, 12);
            this.groupBox3.Name = "groupBox3";
            this.groupBox3.Size = new System.Drawing.Size(320, 125);
            this.groupBox3.TabIndex = 22;
            this.groupBox3.TabStop = false;
            this.groupBox3.Text = "Face Detection";

            this.tbMaxSizeHeight.Location = new System.Drawing.Point(225, 59);
            this.tbMaxSizeHeight.Name = "tbMaxSizeHeight";
            this.tbMaxSizeHeight.Size = new System.Drawing.Size(50, 20);
            this.tbMaxSizeHeight.TabIndex = 10;

            this.label10.AutoSize = true;
            this.label10.Location = new System.Drawing.Point(222, 39);
            this.label10.Name = "label10";
            this.label10.Size = new System.Drawing.Size(41, 13);
            this.label10.TabIndex = 9;
            this.label10.Text = "Height:";

            this.label9.AutoSize = true;
            this.label9.Location = new System.Drawing.Point(150, 43);
            this.label9.Name = "label9";
            this.label9.Size = new System.Drawing.Size(38, 13);
            this.label9.TabIndex = 8;
            this.label9.Text = "Width:";

            this.tbMinSizeHeight.Location = new System.Drawing.Point(85, 59);
            this.tbMinSizeHeight.Name = "tbMinSizeHeight";
            this.tbMinSizeHeight.Size = new System.Drawing.Size(50, 20);
            this.tbMinSizeHeight.TabIndex = 7;

            this.label8.AutoSize = true;
            this.label8.Location = new System.Drawing.Point(82, 43);
            this.label8.Name = "label8";
            this.label8.Size = new System.Drawing.Size(41, 13);
            this.label8.TabIndex = 6;
            this.label8.Text = "Height:";

            this.label7.AutoSize = true;
            this.label7.Location = new System.Drawing.Point(10, 44);
            this.label7.Name = "label7";
            this.label7.Size = new System.Drawing.Size(38, 13);
            this.label7.TabIndex = 5;
            this.label7.Text = "Width:";
 
            this.buttonSetFace.Location = new System.Drawing.Point(234, 88);
            this.buttonSetFace.Name = "buttonSetFace";
            this.buttonSetFace.Size = new System.Drawing.Size(75, 23);
            this.buttonSetFace.TabIndex = 4;
            this.buttonSetFace.Text = "Set";
            this.buttonSetFace.UseVisualStyleBackColor = true;
            this.buttonSetFace.Click += new System.EventHandler(this.buttonSetFace_Click);

            this.tbMaxSizeWidth.Location = new System.Drawing.Point(153, 59);
            this.tbMaxSizeWidth.Name = "tbMaxSizeWidth";
            this.tbMaxSizeWidth.Size = new System.Drawing.Size(50, 20);
            this.tbMaxSizeWidth.TabIndex = 3;

            this.label6.AutoSize = true;
            this.label6.Location = new System.Drawing.Point(150, 16);
            this.label6.Name = "label6";
            this.label6.Size = new System.Drawing.Size(77, 13);
            this.label6.TabIndex = 2;
            this.label6.Text = "Maximum Size:";

            this.tbMinSizeWidth.Location = new System.Drawing.Point(10, 59);
            this.tbMinSizeWidth.Name = "tbMinSizeWidth";
            this.tbMinSizeWidth.Size = new System.Drawing.Size(50, 20);
            this.tbMinSizeWidth.TabIndex = 1;

            this.label5.AutoSize = true;
            this.label5.Location = new System.Drawing.Point(7, 20);
            this.label5.Name = "label5";
            this.label5.Size = new System.Drawing.Size(74, 13);
            this.label5.TabIndex = 0;
            this.label5.Text = "Minimum Size:";

            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(687, 421);
            this.Controls.Add(this.groupBox3);
            this.Controls.Add(this.groupBox5);
            this.Controls.Add(this.ProcessedViewer);
            this.Controls.Add(this.OriginalViewer);
            this.Controls.Add(this.label2);
            this.Controls.Add(this.label1);
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
            this.MaximizeBox = false;
            this.Name = "MainForm";
            this.Text = "Face Detection";
            this.Load += new System.EventHandler(this.MainForm_Load);
            this.groupBox5.ResumeLayout(false);
            this.groupBox5.PerformLayout();
            this.groupBox3.ResumeLayout(false);
            this.groupBox3.PerformLayout();
            this.ResumeLayout(false);
            this.PerformLayout();
        }

        #endregion

        private System.Windows.Forms.Label label1;
        private System.Windows.Forms.Label label2;
        private Ozeki.Media.VideoViewerWF OriginalViewer;
        private Ozeki.Media.VideoViewerWF ProcessedViewer;
        private System.Windows.Forms.GroupBox groupBox5;
        private System.Windows.Forms.Button button_Connect;
        private System.Windows.Forms.Button button_Disconnect;
        private System.Windows.Forms.TextBox tb_cameraUrl;
        private System.Windows.Forms.Label label13;
        private System.Windows.Forms.Button button_Compose;
        private System.Windows.Forms.Label stateLabel;
        private System.Windows.Forms.Label label14;
        private System.Windows.Forms.GroupBox groupBox3;
        private System.Windows.Forms.TextBox tbMaxSizeHeight;
        private System.Windows.Forms.Label label10;
        private System.Windows.Forms.Label label9;
        private System.Windows.Forms.TextBox tbMinSizeHeight;
        private System.Windows.Forms.Label label8;
        private System.Windows.Forms.Label label7;
        private System.Windows.Forms.Button buttonSetFace;
        private System.Windows.Forms.TextBox tbMaxSizeWidth;
        private System.Windows.Forms.Label label6;
        private System.Windows.Forms.TextBox tbMinSizeWidth;
        private System.Windows.Forms.Label label5;
    }
}