Re: [sane-devel] Film scanning and infrared image cleaning

2017-08-13 Thread Julian Hauser 

I take back my comments about the dust removal being overeager. On closer 
inspection these really are all specks of dust, just extremely tiny ones and, 
in my case, the blur induced by the removal is actually more visible than the 
dust that caused it.

On Sun, 13.08.17 19:12, Julian Hauser wrote:

Hello Klaus,

On Fri, 11.08.17 09:05, Klaus Kaempf wrote:

Hi Julian,



* Julian Hauser  [Aug 10. 2017 22:58]:

Hello everyone,



I'm using the Reflecta 10T scanner using the pieusb backend. It mostly works very well, thanks! One 
thing I have noticed though is that if I enable the infrared scratch and dust removal option 
"Clean image" in Xsane, the detected defects get painted over with a blurred dot. On film 
negatives, which have a grainy structure, the results are clearly visible. I've uploaded an example 
here: https://mis.julianhauser.com/index.php/s/MhSuFltcm0CLIMs. It would be very nice if the 
corrections repaired the result taking into account the structure of the neighbouring areas (as for 
example the "healing tool" in GIMP does).





Does the "overpainting" happen in the firmware of the scanner or is
that part of sane?



it's part of sane, resp. the pieusb backend. See
https://anonscm.debian.org/cgit/sane/sane-backends.git/tree/backend/pieusb_specific.c#n1321
where various sane_ir_* functions are called.


I've had a look at the functions that are responsible for the dust removal but 
I have to admit I don't even understand the basic approach taken. Is the author 
of those functions on the list? It would be nice if someone could explain me 
roughly what is happening and where a change would have to be made.

I've also noticed that the scratch and dust removal seems to be a bit 
overeager. If you look at the example image I linked to in the first email you 
can see that the scan is littered with blurred circles. I scanned some photos 
with scratch removal on and then off, and it is clear that most of the 
corrections aren't of anything visible to the naked eye.





Two more things I've noticed with the scanner is that images always
come out reversed left-to-right



All images (color, greyscale, b) ? In all resolutions ?


All the ones I could test are reversed (but that is only various resolutions in 
colour mode currently). Given that the same happened with the Reflecta 
CrystalScan 7200 that I had earlier, I would say it's a general issue.




and greyscale scans make xsane crash. These things don't bother me much
as they are easily fixed with a script after scanning. I can send crash
logs if someone is interested in debugging this however.



Please do ! ;-)


Here's the log of an attempt to scan with xsane using greyscale: 
https://pastebin.com/upMTt9HJ. I've realised that lineart and halftone do not 
work either.

Thanks,
Julian


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Re: [sane-devel] Film scanning and infrared image cleaning

2017-08-13 Thread Julian Hauser 

Hello Klaus,

On Fri, 11.08.17 09:05, Klaus Kaempf wrote:

Hi Julian,



* Julian Hauser  [Aug 10. 2017 22:58]:
> Hello everyone,



> I'm using the Reflecta 10T scanner using the pieusb backend. It mostly works very well, thanks! 
One thing I have noticed though is that if I enable the infrared scratch and dust removal option 
"Clean image" in Xsane, the detected defects get painted over with a blurred dot. On film 
negatives, which have a grainy structure, the results are clearly visible. I've uploaded an example 
here: https://mis.julianhauser.com/index.php/s/MhSuFltcm0CLIMs. It would be very nice if the 
corrections repaired the result taking into account the structure of the neighbouring areas (as for 
example the "healing tool" in GIMP does).




> Does the "overpainting" happen in the firmware of the scanner or is
> that part of sane?

it's part of sane, resp. the pieusb backend. See
https://anonscm.debian.org/cgit/sane/sane-backends.git/tree/backend/pieusb_specific.c#n1321
where various sane_ir_* functions are called.


I've had a look at the functions that are responsible for the dust removal but 
I have to admit I don't even understand the basic approach taken. Is the author 
of those functions on the list? It would be nice if someone could explain me 
roughly what is happening and where a change would have to be made.

I've also noticed that the scratch and dust removal seems to be a bit 
overeager. If you look at the example image I linked to in the first email you 
can see that the scan is littered with blurred circles. I scanned some photos 
with scratch removal on and then off, and it is clear that most of the 
corrections aren't of anything visible to the naked eye.




> Two more things I've noticed with the scanner is that images always
> come out reversed left-to-right

All images (color, greyscale, b) ? In all resolutions ?


All the ones I could test are reversed (but that is only various resolutions in 
colour mode currently). Given that the same happened with the Reflecta 
CrystalScan 7200 that I had earlier, I would say it's a general issue.



> and greyscale scans make xsane crash. These things don't bother me much
> as they are easily fixed with a script after scanning. I can send crash
> logs if someone is interested in debugging this however.

Please do ! ;-)


Here's the log of an attempt to scan with xsane using greyscale: 
https://pastebin.com/upMTt9HJ. I've realised that lineart and halftone do not 
work either.

Thanks,
Julian

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Re: [sane-devel] Film scanning and infrared image cleaning

2017-08-11 Thread Klaus Kaempf 
Hi Julian,

* Julian Hauser  [Aug 10. 2017 22:58]:
> Hello everyone,
> 
> I'm using the Reflecta 10T scanner using the pieusb backend. It mostly works 
> very well, thanks! One thing I have noticed though is that if I enable the 
> infrared scratch and dust removal option "Clean image" in Xsane, the detected 
> defects get painted over with a blurred dot. On film negatives, which have a 
> grainy structure, the results are clearly visible. I've uploaded an example 
> here: https://mis.julianhauser.com/index.php/s/MhSuFltcm0CLIMs. It would be 
> very nice if the corrections repaired the result taking into account the 
> structure of the neighbouring areas (as for example the "healing tool" in 
> GIMP does).
> 

> Does the "overpainting" happen in the firmware of the scanner or is
> that part of sane?

it's part of sane, resp. the pieusb backend. See
https://anonscm.debian.org/cgit/sane/sane-backends.git/tree/backend/pieusb_specific.c#n1321
where various sane_ir_* functions are called.


> Two more things I've noticed with the scanner is that images always
> come out reversed left-to-right

All images (color, greyscale, b) ? In all resolutions ?

> and greyscale scans make xsane crash. These things don't bother me much
> as they are easily fixed with a script after scanning. I can send crash
> logs if someone is interested in debugging this however.

Please do ! ;-)


Klaus
-- 
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 
(AG Nürnberg)

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