Short pnm files

D C Haslam (dch@sirius.demon.co.uk)
Thu, 31 Dec 1998 20:16:53 GMT

I have a Umax 600S connected to an AV-1515, and in general
it seems to work ok with sane 1.0.

However, sometimes the pnm file generated by scanimage or xscanimage
is invalid, the file is generally too short.

Has anyone else seen this? I've been trying different settings, but
don't have anything conclusive yet. 300dpi (the max for this scanner)
seems ok, but lower resolutions seem to suffer. It is affected by the
area scanned.

I ran scanimage with various debugging environment variables set, and
the debug output suggests that sane_read is not returning
all the data from the scanner as this extract suggests:

[umax] merged line as color 0 to line 36
[umax] sane_read: read 4096 bytes
[umax] merged line as color 2 to line 39
[umax] merged line as color 0 to line 37
[umax] merged line as color 2 to line 40
[umax] sane_read: read 233 bytes
[umax] reader_process: buffer of 4563 bytes read; 0 bytes to go
[umax] sane_read: read 0 bytes

(the full session log is over 500 lines, available on request :)

I'll debug some more, but umax.c doesn't make a lot of sense to me
yet, not being familiar with the finer points of scanner interfacing.

David Haslam

--
Source code, list archive, and docs: http://www.mostang.com/sane/
To unsubscribe: echo unsubscribe sane-devel | mail majordomo@mostang.com