[sane-devel] Epson Perfection 610 Issue with 150 dpi scan

[Olaf Meeuwissen]

Alessandro Zummo wrote:
> On Sun, 3 Jan 2010 15:14:38 +0100
> Rainer Dorsch <rdorsch at web.de> wrote:
> 
>> Are these the areas in epson2.c you are refering to:
>>
>>         /*
>>          * Make sure that the number of lines is correct for color shuffling:
>>          * The shuffling alghorithm produces 2xline_distance lines at the
>>          * beginning and the same amount at the end of the scan that are not
>>          * useable. If s->params.lines gets negative, 0 lines are reported
>>          * back to the frontend.
>>          */
>>         if (s->hw->color_shuffle) {
>>                 s->params.lines -= 4 * s->line_distance;
>>                 if (s->params.lines < 0)
>>                         s->params.lines = 0;
>>
>>                 DBG(1, "adjusted params.lines for color_shuffle by %d to %d\n",
>>                     4 * s->line_distance, s->params.lines);
>>         }
>>
>> [snip]
> 
>  Those are two of the involved sections. However I did not wrote
> them so I can just hope they work nicely ;)

That code does the wrong thing.  The epkowa backend fixed the 
s.params->lines calculations in, eh, iscan-1.14.0 (released in 2005).
Search epkowa.c of a recent iscan for "finalise the number of scanlines" 
to see what should be done.

Hope this helps,
-- 
Olaf Meeuwissen, LPIC-2           FLOSS Engineer -- AVASYS Corporation
FSF Associate Member #1962               Help support software freedom
                  http://www.fsf.org/jf?referrer=1962