SAVE IM AGE TO SQL using WEBCAM

SAVE IM AGE TO SQL using WEBCAM

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Touchless.Vision.Camera;
using System.Data.SqlClient;
using System.IO;
using System.Configuration;
 
namespace RadicalGuardMainMenu
{
    public partial class Webcam : Form
    {
        public Webcam()
        {
            InitializeComponent();
        }
 
        private void Webcam_Load(object sender, EventArgs e)
        {
            comboBoxCameras.DropDownStyle = ComboBoxStyle.DropDownList;
            // Refresh the list of available cameras
            comboBoxCameras.Items.Clear();
            foreach (Camera cam in CameraService.AvailableCameras)
                comboBoxCameras.Items.Add(cam);
 
            if (comboBoxCameras.Items.Count > 0)
                comboBoxCameras.SelectedIndex = 0;
 
        }
 
 
        private void btnCapture_Click(object sender, EventArgs e)
        {
            thrashOldCamera();
        }
 
        private CameraFrameSource _frameSource;
        private static Bitmap _latestFrame;
 
        private void btnStart_Click(object sender, EventArgs e)
        {
            // Early return if we've selected the current camera
            if (_frameSource != null && _frameSource.Camera == comboBoxCameras.SelectedItem)
                return;
 
            thrashOldCamera();
            startCapturing();
        }
 
 
        private void startCapturing()
        {
            try
            {
                Camera c = (Camera)comboBoxCameras.SelectedItem;
                setFrameSource(new CameraFrameSource(c));
                _frameSource.Camera.CaptureWidth = 320;
                _frameSource.Camera.CaptureHeight = 240;
                _frameSource.Camera.Fps = 20;
                _frameSource.NewFrame += OnImageCaptured;
 
                pictureBoxDisplay.Paint += new PaintEventHandler(drawLatestImage);
                _frameSource.StartFrameCapture();
            }
            catch (Exception ex)
            {
                comboBoxCameras.Text = "Select A Camera";
                MessageBox.Show(ex.Message);
            }
        }
 
        private void drawLatestImage(object sender, PaintEventArgs e)
        {
            if (_latestFrame != null)
            {
                // Draw the latest image from the active camera
                e.Graphics.DrawImage(_latestFrame, 0, 0, _latestFrame.Width, _latestFrame.Height);
            }
        }
 
        public void OnImageCaptured(Touchless.Vision.Contracts.IFrameSource frameSource, Touchless.Vision.Contracts.Frame frame, double fps)
        {
            _latestFrame = frame.Image;
            pictureBoxDisplay.Invalidate();
        }
 
        private void setFrameSource(CameraFrameSource cameraFrameSource)
        {
            if (_frameSource == cameraFrameSource)
                return;
 
            _frameSource = cameraFrameSource;
        }
 
        //
 
        private void thrashOldCamera()
        {
            // Trash the old camera
            if (_frameSource != null)
            {
                _frameSource.NewFrame -= OnImageCaptured;
                _frameSource.Camera.Dispose();
                setFrameSource(null);
                pictureBoxDisplay.Paint -= new PaintEventHandler(drawLatestImage);
            }
        }
 
        private void btnSave_Click(object sender, EventArgs e)
        {
            string query = "insert into testImage values @picture";
            SqlConnection con = new SqlConnection(ConfigurationSettings.AppSettings["radicalGuardDB"].ToString());
 
            SqlCommand cmd = new SqlCommand(query, con);
 
            MemoryStream stream = new MemoryStream();
 
            pictureBoxDisplay.Image.Save(stream, System.Drawing.Imaging.ImageFormat.Jpeg);
 
            byte[] picture = stream.ToArray();
 
            cmd.Parameters.AddWithValue("@picture", picture);
 
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
        }
    }
}
 
 
The thing is I can't save the image from the pictureBoxDisplay to SQL. Please I really need help on this. I'm converting the pictureBox into a byte array but there's an error in this line (line 123), saying that object reference is not set to an instance... 
 
PLZ COMMENT ANY ONE KNOW PLz