[sane-devel] gamma table value

[Martin Collins]

On Wed, 14 May 2003 20:58:16 +0100
"F J Brooks" <fred@redgrave.screaming.net> wrote:

Hi Fred

I can't speak to your specific problem but maybe I can clarify a
couple of general points for you.

> I've no idea what a 'SuSE binary RPM' is!

You have been downloading source code and compiling it. A compiled
executable program is often referred to as a binary. Modern Linux
distributions supply programs ready made in binary packages so you
don't have to compile them yourself. SuSE uses the RPM package format.
Your SuSE manual should tell you how to install RPM packages.

> It added: 'you may need to remove /dev/null before you can run
> configure again.'

This is bad advice, you did well to ignore it. The files in the /dev
directory are how Linux accesses hardware devices (or pseudo-hardware
devices) and you should not mess with them directly unless you know
what you are doing.

> > [Henning]
> > But that means that you must know what a shell is, how to start
> > programs from the shell, how to read man pages. So it doesn't work
> > without previous knowledge.
> 
> I do not understand this point at all.

"shell" is another word for command line. The online manual for Linux
programs can be accessed by typing "man programname" on the command
line. There is probably a GUI program called "Help Browser" or similar
you can use instead. Other documentation can be viewed in your web
browser at file://usr/share/doc or file://usr/doc

> On my SuSE desktop - both 'root' and 'user' versions, which are
> slightly different - there are a number of icons, such as Trash,
> OpenOffice, CD-R, CD-ROM, etc, etc, including one marked: 'Scanner'.
> This is the icon I clicked.

Such icons are provided by SuSE and are set up automatically when you
install an RPM package. Installing from source may put the programs
in a different place than SuSE expects and will not set up any icons,
so existing icons may no longer work.

> As I stated in my original message, I have also downloaded/installed
> xsane as it seems to be generally recommended., but haven't yet
> tried to use it(none of the articles I have cited tells me how!)

Type "xsane" on the command line. This is generally true for all
programs and is therefore often taken for granted. Xsane is a nice GUI
program very similar to scanner programs on Windows.

> > [Henning]
> > scanimage >image.pnm
> 
> Response: scanner whirred for a short time. Otherwise, no response
> on screen.

It is common for Linux programs to show no output when they succeed.
Only if there is a problem do they tell you about it. This command
should have created a file called image.pnm in the current directory.
If the scan didn't succeed the file may have zero size.

> > [Henning]
> > If that doesn't work, show us the output of:
> >
> > SANE_DEBUG_AVISION=255 scanimage >image.pnm
> 
> Response: None at all.

This should give you reams of output in your terminal window even if
it doesn't work properly.

> You'll forgive my cynicism if, after all these 'adventures', I
> give a hollow laugh when I note that 'SANE' is an acronym for
> 'Scanner Access Made Easy' [!!!]

Before SANE you would have had to write your own driver by reverse
engineering the Windows driver without help or documentation from the
scanner manufacturer. Not easy :-)

You have made life hard for yourself by bypassing all the "user-friendly"
layers that SuSE and others have added on top of Linux. Sometimes this is
necessary if you need a newer version of a program than the one your
distribution provides a package for. In such cases you should first look
for a suitable package made by someone else, starting at the program's
web site then at www.rpmfind.net. Compiling is a last resort.
Beware installation instructions that are old or not specific to your
distribution. Learn how to use SuSE's installation mechanisms.
Considering your level of knowledge and the red herrings you've been
following I'm impressed that you've got as far as you have, but you
really need to read that SuSE manual.
And I'm confident that the guys here will be able to sort you out
eventually.

Martin