Opened 9 years ago

Closed 9 years ago

#5961 closed defect (fixed)

Half pixel shift for registration of TIL

Reported by: Even Rouault Owned by: Even Rouault
Priority: normal Milestone: 1.11.3
Component: GDAL_Raster Version: unspecified
Severity: normal Keywords: til
Cc:

Description

From ​http://lists.osgeo.org/pipermail/gdal-dev/2015-May/041770.html 

We have DigitalGlobe image strips which come with a *.til file.

The geotransform of the til and the separate images have a shift of half a pixel when opened with GDAL.

The reason is that in the GDAL TIL driver the coordinates are treated as outer pixel edge, where as it seems like they describe the pixel center, at least in our cases.

Does  anyone know of a description for the TIL format to verify if the GDAL driver or the TILs from DigitalGlobe are wrong?

For now we fixed it on our side, but you might consider changing the TIL driver to treat the coordinates as pixel center.

Change History (1)

comment:1 by Even Rouault, 9 years ago

Milestone: → 1.11.3
Resolution: → fixed
Status: new → closed

According to ​https://www.digitalglobe.com/sites/default/files/ISD_External.pdf (page 37 and 38), ulx=originX and is "Easting of the center of the upper left pixel of the image."

trunk r29198, branches/1.11 r29199 "TIL: fix half pixel shift in geo registration (#5961)"

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