On Monday 10 July 2006 21:40, 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? > you might want to have a look @ plustek-usbmap.c, where the brightness & contrast adjustment isdone for the plustek backend. It's quite simple and works okay (tm) ;)
HTH Gerhard
