c# store a picture to database

I am not able to insert the picture in database.This is my sample code.I am able to select a image from my computer and display in picture box.Once i try to store the image displayed in picture box to database it says object reference not set to an instance of an object.

This is my sample code.

          namespace picutre_storage
     {
        public partial class Form1 : Form
        {
         public Form1()
      {
        InitializeComponent();
       }

    private void button2_Click(object sender, EventArgs e)
    {
        try
        {

            SqlConnection con = new SqlConnection
                           (@"User ID=sa;Password=password123;Initial Catalog=picuture;Persist Security Info=True;Data Source=ENMEDIA-EA6278E\ENMEDIA");
            //I have used a table named "tblUsers" and fill the fields
            SqlCommand cmd = new SqlCommand("INSERT INTO BLOBTest (BLOBData) VALUES (@BLOBData)", con);

            //Save image from PictureBox into MemoryStream object.
            MemoryStream ms = new MemoryStream();
            pictureBox1.Image.Save(ms,ImageFormat.Bmp);

            //Read from MemoryStream into Byte array.
            Byte[] bytBLOBData = new Byte[ms.Length];
            ms.Position = 0;
            ms.Read(bytBLOBData, 0, Convert.ToInt32(ms.Length));

            //Create parameter for insert statement that contains image.
            SqlParameter prm = new SqlParameter("@BLOBData", SqlDbType.VarBinary,            bytBLOBData.Length, ParameterDirection.Input, false,
                            0, 0, null, DataRowVersion.Current, bytBLOBData);
            cmd.Parameters.Add(prm);
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
        }
        catch (Exception ex)
        { MessageBox.Show(""+ex); } 
    }

      private void button3_Click(object sender, EventArgs e)
       {
        try
        {
            //Getting The Image From The System
            OpenFileDialog open = new OpenFileDialog();
            open.Filter = "Image Files(*.jpg; *.jpeg; *.gif; *.bmp)|*.jpg; *.jpeg; *.gif; *.bmp";
            if (open.ShowDialog() == DialogResult.OK)
            {
                pictureBox2.Image = new Bitmap(open.FileName);
            }
        }
        catch (Exception)
开发者_JAVA技巧        {
            throw new ApplicationException("Failed loading image");
        }
    }

2.There is any way check the size of the image before displaying it in picture box.Thank in advance

On thing i see that you save a file into bmp format and originally that picture exist with let say jpeg or tiff format, so the record is inserted rightly but the picture is refering to a type bmp format and it does not exist. I think you can do somehting like this.

1. when you get the picture in any format you want, then create a thumbnail for this picture store it in a different folder*(like My Pictures\Thumbnails).*
2. Get the extension of the picture,replace it with jpg during creation of Thumbnail.
3. Store this in the database.
4. Retrieve the thumbnails in the picture box. You want.

If you want to know how to create the Thumbnails (saving a file into JPG format then most welcome.