[sane-devel] problems with scanimage

[Henning Meier-Geinitz]

Hi,

On Wed, Dec 14, 2005 at 09:43:13AM -0800, johon Doe wrote:
> I have lot's of problems with scanimage, here some
> examples:
> 
> $ scanimage --mode Gray --custom-gamma=yes
> --gamma-table `gamma4scanimage 1.8 0 11500 16383 255`
> > image.pnm
> scanimage: unrecognized option `--custom-gamma=yes'

The backend you use doesn't seem to provide the option "custom-gamma".
scanimage --help shows all available options.
By the way, which backend and scanner do you use?

> $ scanimage --mode Gray --halftoning "Halftone C (Net
> Screen)" --custom-gamma=yes --gamma-table
> `gamma4scanimage 1.8 0 11500 16383 255` > image.pnm
> scanimage: attempted to set inactive option halftoning

Thwe option "halftoning" seems to exist in your backend, but it
doesn't work in the current mode. maybe it works in mode "lineart"?

> scanimage --brightness 1 >> prova4.tiff
> scanimage: attempted to set inactive option brightness
>
> $ scanimage --brightness 1 --mode Gray >> prova4.bmp
> scanimage: attempted to set inactive option brightness

It's similar in this case. The order of options is important, by the
way. Setting the mode before brightness may help if gray mode uses
option brightness.

You can also check if an option is active in a specific mode like this:

scanimage --mode Gray --help

Bye,
  Henning