[gdal-dev] ​Re: Raster origin coodinates in file header

[Adrien ANDRÉ]

Even, Piero,

thank you very much for your detailed answers !


Adrien


Le 30/06/2015 08:41, Piero Campalani a écrit :
> Adrien,
>
> OGC in its GML standard document -- of course in line with ISO --
> recommends that:/
>
> "When a grid point is used to represent a sample space (e.g. image
> pixel), the grid point represents the center of the sample space (see
> ISO 19123:2005, 8.2.2)"/. ​
>
> ​GML encodes the locations of a raster/gridded-coverage by means of a
> grid of ​0D points.
>
> ​You can always put your raster origin wherever you want, i.e. in
> whatever corner you prefer.
> Alas, there's no way -- that I am aware of -- to specify what is the
> shape of a measurement footprint/sample-space, nor to say if the
> footprint surrounds the point-geometry equally (point is pixel-centre)
> or some other way (point is pixel-upper-left-corner?).
>
> Hence raster creators should probably stick to this recommended encoding
> until standards do not offer more freedom on this :)
>
> ​@seeAlso
> ​http://rasdaman.org/wiki/PetascopeSubsets
> http://rasdaman.org/ticket/680​
>
> -
> ​Piero !​
> ​
>
> On 29 June 2015 at 21:00, <gdal-dev-request at lists.osgeo.org
> <mailto:gdal-dev-request at lists.osgeo.org>> wrote:
>
>     Date: Mon, 29 Jun 2015 11:12:11 +0200
>     From: Adrien ANDR? <adr.andre at laposte.net
>     <mailto:adr.andre at laposte.net>>
>     To: gdal-dev at lists.osgeo.org <mailto:gdal-dev at lists.osgeo.org>
>     Subject: [gdal-dev] Raster origin coodinates in file header
>     Message-ID: <55910BEB.2030307 at laposte.net
>     <mailto:55910BEB.2030307 at laposte.net>>
>     Content-Type: text/plain; charset=utf-8; format=flowed
>
>     Dear list,
>
>     opening 2 rasters with different resolutions i noticed a shift.
>
>     Asking our imagery provider, i was told the origin coordinates they
>     store in image header (JP2 files) are those of the top left pixel
>     center.
>
>     GDAL reads origin coordinates as the top left pixel top left corner
>     coordinates, as i'm used to.
>
>
>     Of course, i fixed my problem, the hacky way, playing with
>     gdal_translate a_ullr option, but:
>
>     How to deal with this?
>     How not to worry about georeferencing each time i load a raster file?
>     Is there any OGC recommendation about origin coordinates storage?
>
>
>     Thanking you in advance,
>
>     Regards,
>
>     Adrien
>
>
>
>
>
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>