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, <[email protected]
<mailto:[email protected]>> wrote:

    Date: Mon, 29 Jun 2015 11:12:11 +0200
    From: Adrien ANDR? <[email protected]
    <mailto:[email protected]>>
    To: [email protected] <mailto:[email protected]>
    Subject: [gdal-dev] Raster origin coodinates in file header
    Message-ID: <[email protected]
    <mailto:[email protected]>>
    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





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