Allegedly, on or about 16 December 2012, Frédéric Bron sent: > 2. with xsane, I have access to the following resolutions only: 75, > 150 300, 600, 1200, 2400, with scanimage: 75, 300, 1200, 2400. > Why is it not the same list? > How can I have access to more values as with the Windows tool where I > could select whatever value I wanted? Educated guess: The list is what's actually supported by the software and the scanner. Putting in *any* value probably doesn't reflect what the scanner actually does, and probably is the software converting the scanned data into the resolution that you think you've picked. Interpolation often introduces horrible errors, or is quite CPU and time intensive if you want to do it better. A scanner can only scan at particular resolutions, if it's a traditional flat bed type of scanner (it has a scanning head with optical sensors in a horizontal line, with the sensors fixed distances apart from each other). The highest selectable resolution start with a 1:1 pixel relationship between scanned pixels and saved data, lower resolutions either skip alternate pixels, or merge them together. It's easy enough to merge one, two, or three pixels together. It's impossible to merge 1 and a bit pixels together, any attempt to do so is a fake. And trying to do the converse, of producing higher resolutions than the scanner can actually do, is also a fake. Yes, you can do optical smoothing to take out jaggies, and make things look higher resolution, but you're not actually increasing the resolution, recording more detail from the scanned object. It's faking it. -- [tim@localhost ~]$ uname -rsvp Linux 3.6.9-2.fc17.x86_64 #1 SMP Tue Dec 4 13:26:04 UTC 2012 x86_64 All mail to my mailbox is automatically deleted, there is no point trying to privately email me, I will only read messages posted to the public lists. -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
