gmane.comp.printing.hplip.devel

PB | 4 Oct 18:55

Strange quality using hpaio sane backend with a C4180


Hi.

Since upgrading to HPLIP v1.7.7 I can finally use my HP C4180 
scanner/printer device for scanning, but the outcome is rather ugly.

In order to give the developers the possibility, to "see" what I'm 
talking about, I've prepared some image samples:

http://www.das-werkstatt.com/c4180/

These noisy-artifacts around the edges seem rather strange and 
unnatural, so I thought I'd post this issue here.
Maybe someone could tell me if that's normal or not - or if that could 
be fixed somehow (settings?).

Thanks,
PB

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Zbigniew Luszpinski | 4 Oct 20:22

Re: Strange quality using hpaio sane backend with a C4180

Thursday 04 of October 2007 18:59:00 PB wrote:
> Since upgrading to HPLIP v1.7.7 I can finally use my HP C4180
> scanner/printer device for scanning, but the outcome is rather ugly.

The current version is 2.7.9.

> In order to give the developers the possibility, to "see" what I'm
> talking about, I've prepared some image samples:
>
> http://www.das-werkstatt.com/c4180/
>
>
> These noisy-artifacts around the edges seem rather strange and
> unnatural, so I thought I'd post this issue here.
> Maybe someone could tell me if that's normal or not - or if that could
> be fixed somehow (settings?).

The scanimage gives sharper picture than WindowsXP. I prefer the one from 
Linux and find it as better quality. If you want to have Windows "quality" 
load gimp, then increase saturation and use blur effect on scanned picture.
This way you will get the same picture as in Windows.

zbiggy

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(Continue reading)

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Suffield, David | 5 Oct 21:51

Re: Strange quality using hpaio sane backend with a C4180

Nice analyses on the image quality. :) 

Our hpaio sane backend performs no up-stream image enhancements, so what
you see is uncompressed RGB or jpeg directly from the scanner. 

The windows scanning solution does performs up-stream image enhancements
which may or may not be desirable.

In order to provide a simple open source scanning solution that can be
generalized for many HP devices, we prefer to leave image enhancements
to other open source tools like Gimp. 

-dave

> -----Original Message-----
> From: hplip-devel-bounces <at> lists.sourceforge.net 
> [mailto:hplip-devel-bounces <at> lists.sourceforge.net] On Behalf Of PB
> Sent: Thursday, October 04, 2007 9:59 AM
> To: hplip-devel <at> lists.sourceforge.net
> Subject: [HPLIP-Devel] Strange quality using hpaio sane 
> backend with a C4180
> 
> 
> Hi.
> 
> Since upgrading to HPLIP v1.7.7 I can finally use my HP C4180 
> scanner/printer device for scanning, but the outcome is rather ugly.
> 
> In order to give the developers the possibility, to "see" 
> what I'm talking about, I've prepared some image samples:

(Continue reading)

headers

PB | 6 Oct 14:56

Re: Strange quality using hpaio sane backend with a C4180


Thanks for your reply Dave!

hm... that's what I thought at first, since the windows-version is so 
incredibly blurred.

However, I can't put my finger on it, but the characteristics of this 
edge-noise just seem strange to me...

The edges of objects seem to be too distorted to fix by some 
plain-vanilla GIMP filters (blur + sharpening afterwards?), since they 
introduce a lot of aliasing effects - but if you say that the image is 
"technically spoken" correct, I'll try to find a useful postprocessing 
effect chain in GIMP to apply.

Thanks,
PB

Zitat von "Suffield, David" <david.suffield <at> hp.com>:

> Nice analyses on the image quality. :)
>
> Our hpaio sane backend performs no up-stream image enhancements, so what
> you see is uncompressed RGB or jpeg directly from the scanner.
>
> The windows scanning solution does performs up-stream image enhancements
> which may or may not be desirable.
>
> In order to provide a simple open source scanning solution that can be
> generalized for many HP devices, we prefer to leave image enhancements

(Continue reading)