-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 m. allan noah wrote: > On Tue, 18 Jul 2006, Bertrik Sikken wrote: > > m. allan noah wrote: >>>> recent model fujitsu scanners dont have native brightness/contrast/gamma >>>> support, instead they use an 256x256 or 1024x256 bit look up table to >>>> convert the raw scan data before 8 bit output. >>>> >>>> while it is true that the 8bit square LUT could be done after scanning >>>> with no data loss, most command line front-ends dont do this, and the 10 >>>> bit lut has 'access' to more data that never gets out of the scanner, so >>>> i would like to extend the backend to provide at least >>>> brightness/contrast for these scanners. >>>> >>>> i need suggestions or pointers to code that i could use. what things i >>>> can find are far over my head, but i have a simple brightness adjustment >>>> that shifts the linear slope of the in-out function up or down, and a >>>> crude contrast setting that changes the slope of the function around the >>>> center of the table. i think both of these methods are likely too >>>> simplistic. >>>> >>>> anyone? > > As far as I know, xsane automatically calculates and downloads a gamma > table for brightness / contrast / gamma if the backend advertises it. > > >> interesting! do you know of a backend that does this? i would like to >> see the option structures which are used... of course, not everyone uses >> xsane, so i might have to steal the code from it :)
I built the gamma table support into the niash backend (I think I also looked at other backends then, as an example). Look for optGammaTable in niash.c Regards, Bertrik -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFEv7lxETD6mlrWxPURAsnZAKCXqDVUSuAvU5ZwOGCL3gvP/2XOlACcCPz2 ScDDtxE1pwV4GAQNNaG+yKQ= =MXK6 -----END PGP SIGNATURE-----
