A mask would solve the problem, but how do you set otbcli_FineRegistration
or otbcli_MeanShiftSmoothing to consider a mask? I do not see any argument
related to the mask
and a mask cannot be set with ExtendedFileName. Perhaps I'm missing a
general convention for setting otb commands to consider a mask?
Thanks
Agus

On Tue, Dec 16, 2014 at 11:12 AM, Julien Michel <[email protected]>
wrote:
>
>  Well, I am not sure that this is such a big issue. As I said, there is
> no global handling of no data values in OTB, but most operations that
> actually require to handle them with care or produce them supports either
> masking or no-data parameters. One big exception is resampling, and we
> would need ITK interpolators to handle these no-data values correctly so as
> to get them working. But there is always a way to work-around this with OTB
> apps (by building a masked image with band-math for instance).
>
> Anyway, the best we can do is read/write/propagate no-data flag from gdal
> through the pipeline, and let filters and applications decide what they
> should do with it. This way "some" filters (mainly ours) would be no-data
> compliant, but this will not hold for a lot of others (any filter from ITK
> for instance).
>
> Lets put up a list of applications/filters that do not handle no-data and
> should (which is more important that automatic reading of the flag I think)
> :
> - Orthorectification and all resampling filters (they produce no data in
> ouptuts, but do not handle no data as input)
> - ...
>
> Regards,
>
> Julien
>
> One more thing : since in OTB we do
>
> Le 16/12/2014 09:21, Agustin Lobo a écrit :
>
>    I think this is an important shortcoming: rs images most often have
> non-data values. In particular,
>  once images are geometrically corrected, they are rotated and have
> non-data values in the
>  edges. Applying window-based operation will produce artifacts if non-data
> values are present.
>  It is worrying that this problem was raised by a user in 2010 and nobody
> actually reacted.
>  If there were a wish list for future otb versions, non-data support would
> be my first one .
>  Best,
> Agus
>
> On Mon, Dec 15, 2014 at 5:55 PM, Julien Michel <[email protected]>
> wrote:
>>
>>  Done.
>>
>> Julien
>> -------- Message transféré --------  Sujet : Re: Fwd: NoData values in
>> otb?  Date : Mon, 15 Dec 2014 17:54:09 +0100  De : Agustin Lobo
>> <[email protected]> <[email protected]>  Pour : Julien
>> Michel <[email protected]> <[email protected]>
>>
>> Thanks a lot for the fast answer. Do you mind sending it to the list
>> and we can discuss there?
>> Regards,
>> Agus
>>
>> On Mon, Dec 15, 2014 at 2:51 PM, Julien Michel <[email protected]> 
>> <[email protected]> wrote:
>> > I am sorry I have been away for 2 weeks and I am catching up with my mails
>> > just today. There is currently no way to handle no-data values at the OTB
>> > level. Gdal is able to read/write a no-data property for datasets, but this
>> > does not cope well with the general pipeline model in OTB (and ITK), as we
>> > do not know what happen to no-data values when chaining several filters
>> > (e.g. resampling for instance). As a result this is considered as an
>> > application dependant parameter : some of our applications explicitely
>> > handle no data value (which must be provided by the user as a parameter).
>> >
>> > Regards,
>> >
>> > Julien
>> >
>> > Le 15/12/2014 10:21, Agustin Lobo a écrit :
>> >
>> >> Julien,
>> >>
>> >> Do you know the answer to this question? I've searched the doc and
>> >> cannot find anything related to it.
>> >> Instead, I've found another user asking the same question in 2010! and
>> >> not getting any answer either...
>> >> http://otb-users.37221.n3.nabble.com/Defining-null-values-td986404.html
>> >> This is also a concern for the band math. For example, is there a
>> >> function to check if a pixel is null or nodata?
>> >>
>> >> Thanks,
>> >> Agus
>> >>
>> >> ---------- Forwarded message ----------
>> >> From: Agustin Lobo <[email protected]> <[email protected]>
>>
>> >> Date: Mon, Dec 15, 2014 at 10:16 AM
>> >> Subject: Fwd: NoData values in otb?
>> >> To: Agustin Lobo <[email protected]> <[email protected]>
>> >>
>> >>
>> >> ---------- Forwarded message ----------
>> >> From: Agustin Lobo <[email protected]> <[email protected]>
>> >> Date: Fri, Nov 28, 2014 at 12:16 PM
>> >> Subject: NoData values in otb?
>> >> To: [email protected]
>> >>
>> >>
>> >> I edit my previous message, as I mean No Data rather than Null values
>> >>
>> >> On Thu, Nov 27, 2014 at 3:49 PM, Agustin Lobo <[email protected]> 
>> >> <[email protected]>
>> >> wrote:
>> >>>
>> >>> is there a way to define a NoData value in the images so that those
>> >>> values
>> >>> are ignored in the computations? In the case of FineRegistration it looks
>> >>> like I get wrong results near the edges  of the image because one of the
>> >>> images
>> >>> has null (which I represent as 0 in the tiff) values in one of the edges.
>> >>> Is defining the NoData value in the tiff sufficient? I guess not
>> >>> according to what I'm seeing, but i might be wrong.
>> >>>
>> >>> Agus
>> >
>>
>>
>>
>>
>>  --
>> --
>> Check the OTB FAQ at
>> http://www.orfeo-toolbox.org/FAQ.html
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>  --
> --
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> http://www.orfeo-toolbox.org/FAQ.html
>
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>
> --
> Julien MICHEL
> CNES - DCT/SI/AP - BPI 1219
> 18, avenue Edouard Belin
> 31401 Toulouse Cedex 09 - France
> Tel: +33 561 282 894 - Fax: +33 561 283 109
>
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