[sane-devel] Scanner-based compression for Fujitsu FI-5900c on 1.0.27?

[Wes Rishel]

The 5900 has a mode where JPEG compression is done in the Fujitsu scanner
backend, thus reducing the bandwidth used in the USB2.0 connection to the
Ubuntu system.

I have seen this working on an Ubuntu 12-based computer. I understand that
fujitsu.c from SANE 1.0.24 was modified by the programmer who was
volunteering for this non-profit back then, but I am not sure that I have
an exact copy of that C file.

I am trying to get the system working on a new computer with Ubuntu 16.04.
We have modified the fujitsu.c file but we are getting an error message. I
don't have the exact message but it was to the effect that an option was
not enabled.

As such I am hoping to get help with these questions:

- Is it true that the only changes necessary to enable the in-scanner JPEG
compression are in fujitsu.c?

- Can someone tell me exactly what those changes are for 1.0.27? Just to
confirm, I think this is build 133.

I have been assuming that this was what required, but perhaps there is
something more?

At line 667 change:

#ifndef SANE_FRAME_JPEG
#define SANE_FRAME_JPEG 0x0B
#define SANE_JPEG_DISABLED 1
#endif

To:

#ifndef SANE_FRAME_JPEG
#define SANE_FRAME_JPEG 0x0B
/*#define SANE_JPEG_DISABLED 1*/
#endif


- At runtime the option being used is in the scanimage arguments is

       --compression JPEG

   Is any other option needed to enable scanner-side JPEG compression?

- Is the --mode color option required for scanner-side JPEG compression on
this scanner?


Thanks in advance.

Regards,

Wes Rishel
Retired Healthcare Computer Nerd

____

"Rainbows are just to look at, not to really understand."

Children's Beguiling Ideas About Science        Proffered by T. K. Cassidy
- Children's Librarian        tkc at kuentos.guam.net
____
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