@Dirk: Thanks, I'll check out Median filters to see how they work out.
@All: Meanwhile, I've did some post-processing tests in GIMP and found out that a sequence of "Despeckle" and "Blur" work wonders! Since this might be an issue for more than just the C4180 scanners, I will post my results on the web - and maybe be able to provide some script for automatically running scans through the GIMP for post-processing. What do you think? Although I totally agree to keep the post-procesing and the scanning backend separate, I still think that a lot of users would be happy with a "ready to use" image immediately after scanning. : ) Yours, Pb [EMAIL PROTECTED] wrote: > Hi > > I think there's some sort of median filter that's being applied to the image > in > order to neutralise eventual "dead pixels". The result of a median filter is > this sort of blurring. > > Dirk > > Selon PB <[EMAIL PROTECTED]>: > > >> Thanks for your reply Dave! >> >> hm... that's what I thought at first, since the windows-version is so >> incredibly blurred. >> >> However, I can't put my finger on it, but the characteristics of this >> edge-noise just seem strange to me... >> >> The edges of objects seem to be too distorted to fix by some >> plain-vanilla GIMP filters (blur + sharpening afterwards?), since they >> introduce a lot of aliasing effects - but if you say that the image is >> "technically spoken" correct, I'll try to find a useful postprocessing >> effect chain in GIMP to apply. >> >> >> Thanks, >> PB >> >> >> >> >> Zitat von "Suffield, David" <[EMAIL PROTECTED]>: >> >> >>> Nice analyses on the image quality. :) >>> >>> Our hpaio sane backend performs no up-stream image enhancements, so what >>> you see is uncompressed RGB or jpeg directly from the scanner. >>> >>> The windows scanning solution does performs up-stream image enhancements >>> which may or may not be desirable. >>> >>> In order to provide a simple open source scanning solution that can be >>> generalized for many HP devices, we prefer to leave image enhancements >>> to other open source tools like Gimp. >>> >>> -dave >>> >>> ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ HPLIP-Devel mailing list HPLIP-Devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/hplip-devel
