dynamic image quality from blobs?

Hi there, I am trying to set a dynamic image quality. My images are stored as blobs in a mysql db. Till now the images are just echoed out to the browser. This workes. Now I would like to add dynamic quality, therefore I tryed to output them with imagejpeg. Unfortuanetelly this does not work at all, and I cant get behind the problem. Has anybody a good idea? Thanx, Merlin ############################################################################ #################### # output header("Content-type: $file_type"); echo $picture_blob; // this would not work: // imagejpeg($picture_blob,"",10); ############################################################################ ####################