ImageData provides the interface to write images to file.
Are there currently (Curl 5) any properties available that can be used
to configure the write process?
Unfortunately I believe the answer to your question is "no." In
particular, ImageData can be used to write out a JPEG file, but the
"quality" setting can't be configured, which is regrettable if your goal
is to write something like an image-editing program. As I recall, the
quality setting in this case is hard-wired to 30% (which probably isn't
what I would pick if I were writing an image-editing program).
This has been on a list of "it would be nice to fix" items for a while,
but hasn't actually been addressed because things like image-editing
programs aren't really representative of the business applications for Curl.