[sane-devel] IR support for pixma devices

[Rolf Bensch]

Hi Gernot,

I just committed simple infrared channel support for CS9000F to git.

Please check the code with your CS8800F. To enable ir support you must
change PIXMA_CAP_TPU to PIXMA_CAP_TPUIR in the CS8800F DEVICE() definitions.

Next I'll do some tests with antidust from
http://www.ciselant.de/projects/antidust/.

Cheers,
Rolf



Am 14.02.2013 19:18, schrieb Rolf Bensch:
> Hi Gernot,
> 
> I added the ml to our discussion. This issue could become system
> relevant for the Pixma backend and/or Sane and/or the frontends. And
> maybe other developers would like to be part of this discussion.
> 
> If I look at the used hardware where Sane is running, I see the whole
> scope from embedded systems with saned running, up to high end pc's with
> "endless" memory.
> 
> In theory a user can scan the whole scan area @ 9600 dpi (with a
> CS9000F). Nobody who knows what he's doing will really do this, but he
> *could*. This edge condition needs approx. 60 GB to hold one 3 channel
> 16 bit uncompressed image (rgb) plus one 1 channel ir image. If he scans
> one 24mm x 36mm slide the size is reduced to 1 GB or 6 GB for one slide
> stripe or 21 GB for the complete slide holder area. Here we shouldn't
> forget the embedded systems!
> 
> If we want to create a rgba image for image post processing, the backend
> would need a buffer size of up to 14 GB (5.3 GB for the complete slide
> holder area) to hold ir data from a previous scan. I see a temp file to
> handle this, otherwise it will run into swap. This also would include an
> image resizing function. The CS9000F scans ir only with 600 - 2400 dpi.
> Rgba frames are not part of the Sane standard, but this could be changed.
> 
> I found another antidust project here:
> http://www.ciselant.de/projects/antidust/.
> 
> As a first step I'll commit my ir extension to git. And we can add ir
> for your CS8800F.
> 
> Then we can experiment with antidust and external image resizing. Maybe
> we can get a copy of duster.c, which was part of the old Coolscan2
> project which isn't available anymore at sourceforge.
> 
> Cheers,
> Rolf
> 
> 
> 
> 
> Am 13.02.2013 17:28, schrieb Gernot Hassenpflug:
>> Hi Rolf,
>> Thanks for the wonderful effort to do the IR scanning. I'm thinking
>> that registration needs to be done in the backend, as that is pretty
>> much dependent on the particular scan resolution set in the front end
>> (the CCD and IR are not necessarily at the same resolution, and the
>> registration also seems to depend on that relationship), or did you
>> manage to do that already? Sorry, no time to check the code this week.
>> I agree the front-end should finally have some kind of functions for
>> removing imperfections based on the IR and CCD scans, but if it will
>> be possible to perform some standard processing (maybe with parameters
>> passed from the front-end) in the backend (as an option), then it will
>> be possible for just a corrected image to be presented to the user, a
>> kind of "quickscan" if you will. The reason I propose this is a) it
>> seems there are few people working on front-ends (as far as I can
>> tell), b) it sounds like it is possible to accomplish, c) it will be a
>> major step forward compared to what was available before, and could be
>> forked and/or ported to front-ends later, and finally d) backends are
>> more likely to be included everywhere, whereas front-ends I am not so
>> sure about. Maybe there are several memory and other resource
>> considerations as well (front-ends may be more unstable, memory leaks,
>> etc.).
>>
>> Just my 2 cents worth.
>> Regards,
>> Gernot
>>
>>
>> Am 12.02.2013 23:22, schrieb Rolf Bensch:
>>> Hi,
>>>
>>> Recently I added ir scan as separate image for my CS9000F (pls. see
>>> attached patch). But Google cannot show me a proper way how to process
>>> both files (rgb and ir) to reduce dust with gimp or imagemagick. I found
>>> an old project which also has been discussed in the Sane ml, but it
>>> isn't online anymore
>>> (http://web.archiveorange.com/archive/v/O5zM9kE6TYpdOuGzAjGo).
>>>
>>> I think that the backend should simply scan. Any post processes should
>>> be handled from a frontend or another specialised program.
>>>
>>> I found an old Sane project to generate rgba files (coolscan;
>>> http://andreas.rick.free.fr/). Xsane has some normally not compiled rgba
>>> features and can save a "Sane rgba" file. But this project defines a
>>> 4-channel color space.
>>>
>>> I already started with some 4-channel rgba implementations, but it seems
>>> to be too heavy to hack it into Sane / the backend without any feedback
>>> from other Sane developers.
>>>
>>> I would like to add something like a "save as rgba" function to
>>> scanimage or scanbd. This would enclose scanning two images (rgb and ir)
>>> from the backend and save them as one rgba (png) file. With this we can
>>> avoid any changes to the Sane standard. And we can use external programs
>>> like gimp to handle dust removal (I guess there are some plugins
>>> available to handle rgba files).
>>>
>>> Rolf
>>>
>>>
>>>
>>> Am 11.08.2012 14:25, schrieb m. allan noah:
>>>> The biggest problem is that the sane standard does not allow us to
>>>> return the IR channel to the frontend. If you do all the correction in
>>>> the backend, I suppose that is not required. You should try to spin as
>>>> much of the code as you can into a generic sanei_* library.
>>>>
>>>> allan
>>>>
>>>> On Sat, Aug 11, 2012 at 7:41 AM, Gernot Hassenpflug
>>>> <aikishugyo at gmail.com> wrote:
>>>>> Hello Allan, Rolf,
>>>>> I received a request today from a Debian User Forums member who bought
>>>>> a 2nd-hand CanoScan 8800F. He reports that VueScan works fine with IR
>>>>> for noise removal under Windows, but lacks such support under linux
>>>>> (which was news to me). He will try to compile SANE backends (I gave
>>>>> him instructions), but wishes to know if there is a chance in future
>>>>> of adding IR support to SANE. At this point, I think only the 8800F,
>>>>> 9000F and a couple of the high-end MP devices use such functionality.
>>>>>
>>>>> In the past, 2 people (myself, and a gentleman from Belgium) were
>>>>> working on implementing IR, and we ended up having to do piece-wise
>>>>> registration of the IR image with the CCD image, since the IR image is
>>>>> distorted w.r.t. to the CCD image. At that point we have stopped and
>>>>> the experimental code (stand-alone) has been untouched for perhaps a
>>>>> year.
>>>>>
>>>>> I would be interested in continuing work on this, as it appears to me
>>>>> that a) more scanners in the pixma backend will benefit from this
>>>>> functionality in future, b) the code would be portable to other
>>>>> backends, where there are Canon scanners supported that use IR (e.g.,
>>>>> genesys backend, I believe).
>>>>>
>>>>> As I recall, there were some issues related to new dependencies (maths
>>>>> libraries, I think), but I think that if I can solve to some level of
>>>>> satisfaction the issue of registration, we should be able to
>>>>> incorporate IR noise reduction as an experimental feature into the
>>>>> development code.
>>>>>
>>>>> Any opinions on this?
>>>>> Regards,
>>>>> Gernot Hassenpflug
>>>>
>>>>
>>>>