to make that a bit more clear,
to thumbnail an image i would call thumb.php (img src = thumbnail.php?im=imagename.jpg)
to get image from database i call <img src="display.php?id=<? echo "$row[0]"; ?>">
but i just cant see a way round getting the image from the database then thumnailing it as calling from database is just getting the data from blob field then displaying it as an image.
Hope this explains it a bit better