The growing usage of digital cameras will alter the equation further, with the digital image being superior to a traditional derivation from it. The medium of the electronic file may not be the reason for an inferiority, it could be the capture process. At the moment it is prohibitively expensive to achieve this quality, with digital reproductions being more costly than transparencies to copy without offering better quality to justify the expense. The size of the files needed to obtain superior quality is a major drawback. They have build up this skill with respect to transparencies.
Enlargement is a known area where the electronic image proves inferior.
Copyright issues are the main concern for the supplier, regardless of the medium. Most suppliers do not want images manipulated, but recognise that it will go on in a minority of cases and that they have little power to stop it. Most aren t worried about the individual user, but abuse in the commercial sphere involving alteration of the image wouldn t be tolerable. Any alterations would have to be a part of the negotiation of the license. Casual users manipulating images for personal use are not a major concern.