[Gdal-dev] creating a BMNG world file

[Matt Wilkie]

Hi there,

I'm trying to create a valid world file for Blue Marble Next Generation 
500m resolution png's. From reading the docs, I've created one for the 
A1 tile which looks like:

         0.004166666667
         0.0000000000
         0.0000000000
         -0.004166666667
         -180
         90

and when I load one of those images up with other data, it looks like 
it's in the right place. However when I use gdal_translate to convert it 
to 1% of original size the Lat/Long insertion point changes:

	0.4166666667
	0.0000000000
	0.0000000000
	-0.4166666667
	-179.7937500000
	89.7937500000

is this right? Or should the starting lat-long be offset by half a pixel 
width (and in what direction?)?

thanks in advance,

-- 
matt wilkie
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