Thanks for your timely response. Well the PDF was generated at the source by different form such that I didn't face this problem, that new version of the file worked for me.
On Mon, Dec 14, 2015 at 7:20 PM, Even Rouault <[email protected]> wrote: > Le lundi 14 décembre 2015 13:25:13, Rahkonen Jukka (MML) a écrit : > > Hi, > > > > There is something odd in the PDF. It is without coordinate system and > > perhaps because of that the top-left coordinates are (0,0) and north > > coordinate is increasing from top to bottom. Probably the "Invalid length > > for GPTS object" error does not have any effect on this. > > It does have an effect. The error messages indicates that the geospatial > tags > are ignored, thus the non-georeferenced coordinates which are displayed. > > I've looked at that file a bit and the georeferencing is unusual. It uses > Adobe > ISO 32000 georeferencing but with only 2 tie-points instead of 4 as usual. > The > spec doesn't mention the number of tie-points, but the driver assumes 4, > based > on test samples. It has also unusual MediaBox coordinates (non 0 lower left > corner) > I've removed locally the limitation and did some fiddling in the code to > generalize it, but I don't manage to get a good overlay with a basemap. I > can > get something roughly in the target area, but there is a rotation term > that is > clearly missing. But with only 2 tiepoints, the solver of GCPs to > geotransform > cannot produce any rotation term and assumes linear stretching of > coordinates. > You have to make assumptions as you've the 6 coefficients of the > geotransform > matrix to compute, but only 4 equations. In that case, to recover rotation > terms, it would probably have to make the assumption that the pixels are > square instead (you'd have only 4 unknowns: x,y of top-left corner, pixel > size, rotation angle). I didn't investigate further for now. But it seems > unwise from the data producer to produce only 2 tiepoints because of the > above > mentionned ambiguity. As far as I can see, the PDF spec doesn't tell what > to > do in that case. > > Even > > -- > Spatialys - Geospatial professional services > http://www.spatialys.com > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev
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