JPEG/TIF alphabet soup
2 messages in this thread
I'm working on a database application using Superbase for Windows (I'm in
the home stretch, have just forked out for the developer's edition and
they tell me they're no longer updating the program .. thought this only
happened in Amigaland).
But I digress … this database has scanned images in it, 72dpi to appear
on screen and hopefully a higher resolution bitmap of each product to
appear in a catalog run off on a laser printer.
But if we go to 150 or 300dpi on the version for the catalog, we're going
to need huge amounts of hard drive space just to put these image files.
I'm wondering if there is anything I can do through Imagemaster to
compress them.
Superbase doesn't support JPEG, but it does support TIFF and GIF. I took a
500K 160dpi TIFF file, saved it as a JPEG file in IM then saved that
resulting file as a TIFF and it ended up about 300K. Is this reasonable
logic or am I attempting something completely foolish here? I know JPEG is
a lossy compression, but since these pix are only going to appear at about
1.5 square inches, I figure I can live with that. I have no idea what
happens to the data if it is compressed, then saved as a TIF. I haven't
printed them out to check, everything looked fine on the screen, but IM
was converting everything to AGA 256 anyway. (BTW, they are B&W scans).
Can anyone point me in the right direction here, or should I tell the
client to buy a big hard drive?
Thanks,
Barbara
Well, when you save in JPEG, you're essentially filtering the image. This
is because JPEG loses some image information every time you save an image.
Then when you saved in TIFF, there were fewer changes in the image and so
it compressed more effectively.
Image data takes huge amounts of room, and the more accurate the image is,
the more this is so, generally. Smoother images take less space in
compressed file formats – so perhaps you might get some good results (even
better than pre-jpegging) by trying our lowpass filter in the process
panel; or, if you can wait a week or two, our gaussian filter.
–Ben
…via AutoPilot