primax: New release and Re: primax_scan.c gamma
Subject:
New release and Re: primax_scan.c gamma
From:
####@####.#### (Thomas Schano)
Date:
17 Jan 2000 23:42:58 -0000
Message-Id: <3883A4F2.E1F25C66@t-online.de>
Gustaf Kroling schrieb:
>
> Hello Marco and Thomas,
>
> The driver for Colorado Direct 9600 is now almost usable if
> you think that
> 100 dpi is the only resolution you need. :-)
>
> But I am confused by this gamma stuff. I could not get the
> colours right
> ( comparing with scans made with the primax software ) and
> found that the
> colourtable was different. After some digging the net and
> even checking my
> old textbook on tv I found that gamma is applied directly on
> the normalised
> signal, not on 'signal-.5' as it is done in
> 'calc_color_table'.
>
> Any comments?
Remember the driver is only an alpha-version! I think Marco did his
best. As I remember he used the table from some scanns and tried to find
a function correlating to it. Until the funktion that produces the
color-tables is correctet (written like the definitions of gamma and so
on says) use the funktions of GIMP or other image-tools to correct the
gamma values.
>
> btw: when trying to change this I had some problems entering
> the gamma value
> in the command line. When parsed the gamma takes the value
> of the brightness
> and it is only the red colour that gets updated. Have I
> broken something??
I don't think so. The function isn't debuged, yet.
>
> Gustaf
Last but not least: There is a new alpha-release of the driver on my
webspace at: http://home.t-online.de/home/schano/primax_scan.html
Thomas
