[sane-devel] "stop and go" and colour lines with epson 1250

Prakash K. Cheemplavam PrakashKC@gmx.de
Fri, 07 May 2004 17:04:15 +0200


Hi,

> the 1250 is a "stupid" LM983x based scanner which knows nothing about
> jpeg compression. The stop and go is a "feature" of the LM983x to avoid
> data loss (of course you encounter this problem...)

So I tried again in windows and here the stop and go just appears with 
very high reslotions (600dpi) and very big pictures (horizontallly 
speaking). But the pauses are much shorter. Nevertheless I don't get 
these coloured lines in windows, so I think it is a bug of the plustek 
back-end...

And yes, it is just a usb1 scanner.

> I think that the libusb and or the usb-stack itself is the problem. I've
> currently not testet here with 2.6 kernels.
> Another thing is the image size you scan. Tests showed, that scanning
> only small portions of a picture in 600dpi will work fine (of course - less
> data), while scanning larger portions will not work very well, but full-size
> scanning @300dpi should be no problem, at least with the plustek backend.

Nope, even at 300 dpi I get those problems in Linux. As I said, I use 
plustek back-end with sane back-ends 1.0.14.

> Can you switch back to 2.4 kernel?

Not on my main machine, as it is bleeding edge, and glibc is compiled 
with NPTL, so a 2.4 would break stuff. I could try on another machine, 
but not today...

Thanks for the quick responses. I will try how 2.4 reacts...

Prakash