Hi all,
I have some questions about GMLJP2 parameters concerning location.
*1) Description*Some JP2K images have a pixel origin different than (0 ; 0)
(DIMAP products for example).
In such cases, the GML header looks like like:
<gml:GridEnvelope>
*<gml:low>7 7</gml:low> <========== Different than "0 0"*
<gml:high>1000 1000</gml:high>
</gml:GridEnvelope>
This origin coordinate should be taken into account for pixel location (See
OGC 05-047r3 p93):
<element name="startPoint" type="gml:integerList" minOccurs="0">
<annotation>
<documentation>
Index position of the first grid post, which
shall lie somwhere in the GridEnvelope. If absent, the
startPoint is equal
to the value of gridEnvelope::low from the grid definition.
</documentation>
</annotation>
</element>
It seems that this offset is not taken into account by GDAL location
function.
*2) How to reproduce*
2.1) Data creation
Reference (no offset) image:
gdal_create -of JP2OpenJPEG -co GMLJP2=YES -outsize 100 100 -bands 3 -burn
0 -burn 255 -burn 0 -a_srs epsg:32632 -a_ullr 500000 500100 500100 500000
Offset_0.jp2
Image with offset:
sed s/"<gml:low>0 0"/"<gml:low>7 7"/g Offset_0.jp2 > Offset_7.jp2
2.2) Location test
echo "0 0" | gdaltransform Offset_0.jp2 Offset_7.jp2
0 0 0
*3) Question:*
Shouldn't we have a 7 pixels offset between the 2 images
Cheers
Philippe
The information in this e-mail is confidential. The contents may not be
disclosed or used by anyone other than the addressee. Access to this e-mail by
anyone else is unauthorised.
If you are not the intended recipient, please notify Airbus immediately and
delete this e-mail.
Airbus cannot accept any responsibility for the accuracy or completeness of
this e-mail as it has been sent over public networks. If you have any concerns
over the content of this message or its Accuracy or Integrity, please contact
Airbus immediately.
All outgoing e-mails from Airbus are checked using regularly updated virus
scanning software but you should take whatever measures you deem to be
appropriate to ensure that this message and any attachments are virus free.
_______________________________________________
gdal-dev mailing list
gdal-dev@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/gdal-dev
