This from Sane-development-list: Message: 3 Date: Mon, 16 Apr 2007 17:12:20 +0200 From: JKD <[EMAIL PROTECTED]> Subject: Re: [sane-devel] Scanning produces black images To: [EMAIL PROTECTED] Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset=us-ascii
El Mon, 16 de Apr de 2007, a las 02:50:01PM +0200, Gerhard Jaeger dijo: > > On Montag, 16. April 2007, JKD wrote: > > [SNIPSNAP] >>> > > > This is also an issue with the Plustek backend, reported by various >>> > > > Ubuntu and Gentoo users. As already stated by PhobosK, the problem is >>> > > > the kernel option CONFIG_USB_SUSPEND. This in deed is needed for >>> > > > laptop >>> > > > users. It is currently marked as "experimental" but already used by >>> > > > various >>> > > > distros. >>> > > > >> > > >> > > That was my first thought. But if it's a kernel problem neither xsane >> > > nor scanimage would scan successfully. And in two different compilations >> > > of >> > > hp3900, ubuntu's one fails and my last compilation works. >> > > >>> > > > I think the problem really is, that libusb does not know anything >>> > > > about that >>> > > > suspend stuff and therefore we have more or less no possibility to >>> > > > wakeup >>> > > > the port, where the scanner is connected to. >> > > >> > > I think you're right. But may be libusb is already updated in debian >> > > unstable. That would explain that my compilation works in ubuntu and >> > > library provided by ubuntu in libsane-extras package doesn't. So my >> > > conclusion would be the same. Backends need to be compiled against >> > > current version of libusb. > > > > Could you please check which version of the libusb you/they use? Debian: libusb-0.1-4 0.1.12-6 libusb-dev 0.1.12-6 Ubuntu: libusb-0.1-4 0.1.12-2 libusb-dev 0.1.12-2 >>> > > > One thing that could be observed: In all cases, scanimage works fine >>> > > > - guess >>> > > > this is because it never closes the port until the scan process is >>> > > > done. >> > > >> > > I'm confused. Why should exist any difference between scanimage and >> > > xsane when >> > > both frontends use the same SANE API to access usb scanners? > > > > Guess it's the workflow. When you call scanimage, then the scanner is > > openend, > > detected, configured, scanning is done, closed. > > XSane tries to open and detect, then closes a device. Then then scan is done > > upon request. And I think after the first close, the device (or the port) > > will > > be suspended. I've compiled SANE backends in ubuntu. Instead of installing all project I've just overwritten libsane-hp3900.la and libsane-hp3900.so.1.0.18 in /usr/lib/sane with the ones generated in this compilation and xsane works retrieving scanned image without problems. Jonathan Bravo Lopez -- Canon Lide25 (plustek backend) scanner does not scan via gui https://bugs.launchpad.net/bugs/85488 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
