C#

// where w and h are width and height from image list<br />
Bitmap bmp = new Bitmap(w,h);<br />
<br />
// create a graphics object from new bitmap<br />
using(Graphics g = Graphics.FromImage(bmp))<br />
{<br />
<br />
// make the image all white<br />
g.FillRectangle(Brushes.White,0,0,bmp.Width,bmp.Height);<br />
<br />
// calculate centering point for image... I hope this is right...<br />
int x = (w - bmp.Width) / 2;<br />
int y = (h - bmp.Height) / 2;<br />
<br />
// Put image into the bitmap at x,y in the new bitmap<br />
g.DrawImage(original_bmp,x,y);<br />
}<br />
<br />
// bmp is now your new thumbnail<br />
<br />

private void DrawReversibleRect( Point p1, Point p2 )
{
	Rectangle rc = new Rectangle();			
	
	// Normalize the rectangle.
	if( p1.X < p2.X )
	{
		rc.X = p1.X;
		rc.Width = p2.X - p1.X;
	}
	else
	{
		rc.X = p2.X;
		rc.Width = p1.X - p2.X;
	}
	if( p1.Y < p2.Y )
	{
		rc.Y = p1.Y;
		rc.Height = p2.Y - p1.Y;
	}
	else
	{
		rc.Y = p2.Y;
		rc.Height = p1.Y - p2.Y;
	}			
			
	// Draw the reversible frame.			
	Rectangle r = pictureBox1.RectangleToScreen(rc);
	ControlPaint.DrawReversibleFrame(r,this.BackColor,FrameStyle.Dashed);
			
}