Martijn Mulder schreef:

Some code to illustrate the problem:

using System.Drawing;
using System.Windows.Forms;
class MyForm:Form
{
 override protected void OnPaint(PaintEventArgs a)
 {
  Bitmap bitmap=new Bitmap(2,2);
  Graphics graphics=Graphics.FromImage(bitmap);
  graphics.Clear(Color.Green);
  graphics.DrawLine(Pens.Red,1,1,2,2);
  graphics.Dispose();
  a.Graphics.DrawImage
  (
   bitmap,
   new Rectangle(0,0,200,200),
   new Rectangle(0,0,2,2),
   GraphicsUnit.Pixel
  );
 }
 [System.STAThread]
 static void Main()
 {
  Application.Run(new MyForm());
 }
}

I don't understand the statement "searched in vain".  How did you
search?  When I type in "InterpolationMode" into the MSDN web site
search box, this is the first page that is listed in the search results:

http://msdn2.microsoft.com/en-us/library/system.drawing.drawing2d.interpolationm
ode.aspx

I don't know for sure that any mode will do exactly what you want.  But
you might want to try InterpolationMode.NearestNeighbor.  That might do it.

Pete