Hi The canon lide 35 is now scanning in color at any resolution. No calibration yet. I'd like the calibration code to use a more generic interface to the scanning logic before. But that will have to wait.
This time i want to propose a new mechanism for generating slope tables in the genesys backend, which i implemented for my work. In my opinion it is sufficient to describe one slope for each step type. This slope is truncated as soon as the exposure time is reached. This leads to a variable step count, which can be used to shorten the acceleration/deceleration considerably. I used slopes derived from a start step time(vstart), a final step time(vend), a power(g) and a step count(steps): p[i] = (i/(steps-1))^g t[i] = vstart*(1-p[i])+vend*p[i] For i in 0..(steps-1). Pros: + less Constants + a means for calculating exposure time(which is limited by maximum motor speed and number of pixels processed per line) Cons: - variable step count - may be not applicable to all supported scanners - breaks the current code I attached the code i am using. Related to this and just out of interest: Does the gl646 expect its slope tables to contain STEPNO*2 resp. FASTNO*2 steps, too? Regards, Pierre -------------- next part -------------- A non-text attachment was scrubbed... Name: genesys_gl841_part.c Type: text/x-csrc Size: 1927 bytes Desc: not available Url : http://lists.alioth.debian.org/pipermail/sane-devel/attachments/20050815/fc225754/genesys_gl841_part.c -------------- next part -------------- A non-text attachment was scrubbed... Name: genesys_part.c Type: text/x-csrc Size: 3916 bytes Desc: not available Url : http://lists.alioth.debian.org/pipermail/sane-devel/attachments/20050815/fc225754/genesys_part.c From o...@member.fsf.org Mon Aug 15 05:17:55 2005 From: o...@member.fsf.org (Olaf Meeuwissen) Date: Mon Aug 15 05:10:50 2005 Subject: [sane-devel] Epson Perfection 3490 PHOTO In-Reply-To: <m3ek911kar....@pacbell.net> (Bjorn Solberg's message of "Wed, 10 Aug 2005 15:47:24 -0700") References: <m37jet91od....@pacbell.net> <200508102259.52110.oliver.schwa...@gmx.de> <m3ek911kar....@pacbell.net> Message-ID: <87d5of4xoh....@qed.penguin.lib.org> Bjorn Solberg <bjorn_s...@hekneby.org> writes: > Oliver Schwartz writes: > >> Hi, >>> I recently got the Epson Perfection 3490 PHOTO scanner. > >>> Does anyone else have any experience with this scanner, and/or can >>> tell me whether it is (or will be in the near future) supported by >>> SANE? Any pointers on how I can make it work with SANE is much >>> appreciated. > >> I got some infos and a patch concerning this scanner. I'll add support >> for it to the snapscan backend in the next few days. I'll let you >> know if the code is in CVS, so you can test it. The 3490 and 3590 are similar to the 2480 and 2580 respectively. You should not have much trouble getting these to work with the snapscan backend. > That sounds like good news, I hope the patch is simple and that it'll > work well. So it will use the snapscan backend, not the epson one? Yes, it will use the snapscan backend. This scanner does not speak the EPSON ESC/I protocol which the epson backend assumes. -- Olaf Meeuwissen FSF Associate Member #1962 sign up at http://member.fsf.org/ GnuPG key: 30EF893A/2774 815B DE83 06C8 D733 6B5B 033C C857 30EF 893A Penguin's lib! -- I hack, therefore I am -- LPIC-2
