Image.beginupdate ?

I'm not sure how many times you are drawing on the image canvas, but since you said 'alot', you may want to try what's called page filpping. Whenever you draw directly on a visible canvas rapidly and a draw does NOT sync with the monitor's refresh rate you get some flicker. Try to not draw something on a part of a visible canvas. Only replace the ENTIRE image with a memory bitmap that you have drawn on. Flip a whole page to the image instead of a piece of a page. This may seem like a backwards way (more work instead of less) to do it, but it tends to sync together with the refresh rate better. Oh, a TImage has some update routines that may kick in. You may want to try a PaintBox or Do all the rapid drawing in a Rect on the Form's Canvas. If your drawing is not rapid, you could try DoubleBuffer := True;

I has the same problems with standard delphi components. Best solution I found it do NOT use it, if you want nice graphic application.
I use components from http://www.stuckindoors.com/dib/.
It solved most of my problems. The biggest disadvantage (for me) is that it cannot run in 256 colors mode.

maybe it helps to place the timage on a tpanel

Slick812: I tried to create an invisible image and then paint on the real image using this code     VisibleImage.Canvas.Draw(0,0, TempImage);

It helps a bit but not much, am I doing the right thing?

Slavak: thanks for you tip, the component does not work with Delphi 6 yet, so I will way for that to come.

Ahh now I get it. You are right, I used a paintbox and 99% flicker free :)