[sane-devel] Standard option definitions

[Oliver Rauch]

Dave Close wrote:
> 
> I had mentioned SANE_DESC_SCAN_SPEED, SANE_DESC_CAL_LAMP_DEN,
> SANE_DESC_SCAN_LAMP_DEN, and  SANE_DESC_SELECT_LAMP_DENSITY. All of
> these are listed in saneopts.h. If they are hardware-dependent, they
> should not appear there, but should appear only in the header file
> associated with the specific backend.

Yes, there are too much options listed in saneopts.h

> I also don't see why scanning speed should be less standardized than
> brightness or contrast (for example), or specifically for the scanning
> mode (gray, mono, lineart, etc). Many backends use the speed option,
> presumably because they find it useful. However, there is no common
> definition for the type of values associated (string or numeric) or
> for the option values.

How do you want to define it, as bool (some backends may have only
slow/fast) or as int (other backends may have more than 2 speed settings).

 
> Can anyone answer my specific question about the LAMP options: should I
> understand that "density" is, in some sense, equivalent to "intensity"?

that is the terminology used in the umax protocol. I think it is equivalent
to intensity. But I don´t think that we can make a well known option of
this because I can not say if the intensity is a linear, exponential,
logarithmical or a custom function - and I think no user backend author
can tell you about that if the backend supports such function. So it
does not make much sense to define this option as well known.

When we define an option as well known we have to know what happens
when we double a value.

Bye
Oliver

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