My driver process the threshold at present . If the value of pixel greater than the threshold ,the value of pixel is set 255. Otherwise the value of pixel is set 0. <br><br><div class="gmail_quote">2008/6/23 m. allan noah <<a href="mailto:kitno455@gmail.com">kitno455@gmail.com</a>>:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div><div></div><div class="Wj3C7c">On 6/23/08, Daniel Glöckner <<a href="mailto:daniel-gl@gmx.net">daniel-gl@gmx.net</a>> wrote:<br>
> On Mon, Jun 23, 2008 at 05:04:57PM +0800, eagleskycloud wrote:<br>
> > My driver process threshold while lineArt scan now. If XSane could<br>
> > process threshold, my driver would get simple.<br>
><br>
><br>
> IMHO lineArt should be advertised only for devices that can do the<br>
> conversion in hardware. Doing it in hardware has the benefit of reduced<br>
> USB/SCSI bandwidth. Drivers should not cover up for cheap hardware.<br>
><br>
> There is a list of planned features for XSane.<br>
><br>
> <a href="http://www.xsane.org/xsane-future.html" target="_blank">http://www.xsane.org/xsane-future.html</a><br>
><br>
> If you want lineArt conversion to be included there, you need to contact<br>
> the author. He is no longer on this mailing list.<br>
<br>
</div></div>this is a place where i disagree with daniel, for two reasons-<br>
<br>
1. It would still help with bandwidth in the net backend case, which<br>
sould like it might become the standard in some future version of<br>
sane.<br>
<br>
2. it is good if all backends present a similar interface, so that<br>
front-ends like scanimage can still have access to these functions.<br>
<br>
to that end- i have been working on a sanei_threshold library that<br>
backends of dumb scanners could share. it still has the same effect of<br>
code only in one place. i need a good algorithm though- eagleskycloud-<br>
what mechanism were you planning to use? straight threshold, or<br>
something adaptive?<br>
<br>
allan<br>
<font color="#888888">--<br>
"The truth is an offense, but not a sin"<br>
</font></blockquote></div><br>