var
FRect:TRect;
begin
Image2.Picture:=nil;
FRect.Left:=0;
FRect.Top:=0;
FRect.Right:=Image1.Width;
FRect.Bottom:=20;
Image2.Canvas.CopyRect(FRect,Image1.Canvas,FRect);
while FRect.Bottom<Image1.Height do
begin
Sleep(100);
Self.Image2.Update;
FRect.Top:=FRect.Bottom;
if Image1.Height-FRect.Bottom<20 then
FRect.Bottom:=Image1.Height
else
FRect.Bottom:=FRect.Bottom+20;
Image2.Canvas.CopyRect(FRect,Image1.Canvas,FRect);
end;