[sane-devel] Out of Memory error when scanning at high DPI

[Olaf Meeuwissen]

Gerard Klaver <gerard at gkall.hobby.nl> writes:

> On Thu, 2006-11-16 at 09:13 -0500, Mark Richards wrote:
>> Hi,
>> I have an Epson Perfection Photo 4990 (GT-X800) scanner connected by
>> USB to my PC (Athlon 64 3200 1GB ram 5GB swap, FC5).
>> 
>> scanimage --version : scanimage (sane-backends) 1.0.18 ; backend
>> version 1.0.18
>> 
>> Scanimage -L : device `epson:libusb:002:009' is a Epson GT-X800
>> flatbed scanner
>> 
>> I can scan fine at 1200dpi (16-bit colour) or 2400 (8-bit colour) but
>> when I try to scan at anything higher I get an Out of Memory error.
>> It is my understanding that scanning at 4800dpi should be possible
>> with this scanner.  Any suggestions? 
>> 
>> Thanks,
>> 
>> Mark
>> 
> With export SANE_DEBUG_EPSON=255

You don't really want to do that at 4800dpi ;-).  It outputs a single
line for every sample.  Use 25 instead of 255 for more useful output
and mail me a (compressed) debug log.

> and then start scanimage, check the logs for some info,
>
> For a A4 300dpi (24 bits, 8 bits per color) scan you get about 25Mbyte
> of data, for 600dpi about 100Mbyte, for 1200dpi about 400 Mbyte, for
> 2400dpi about 1600Mbyte.

Mark mentions 1GB RAM ... if the frontend attempts to keep the whole
scanned image in memory than at 4800dpi, 24bits he may be hitting the
limit.

Whereabouts does the out of memory occur?  Somewhere right at or near
you start the scan or after you are more than halfway through the
scan?

Hope this helps,
-- 
Olaf Meeuwissen                          EPSON AVASYS Corporation, SE1
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