[Gdal-dev] warp and translate problems

Chris Hodgson chodgson at refractions.net
Wed Oct 6 12:59:21 EDT 2004


I'm working with TIF orthophoto files, warping them from UTM to BC 
Albers projection, and converting them to JPEG-2000 format.
I have a few questions:

1) it seems that it is not possible to do this in one step using 
gdalwarp and specifying the output format -  I'm guessing the same is 
true for gdal_translate and specifying the  output projection?  I 
suppose this is just a limitation of the more complicated output format 
drivers?

2) I'm starting with .tif and .tfw files, then gdalwarp gives me single 
geotiff file. then when I use gdal_translate to convert to jp2 format, I 
don't have any georeferencing (no wld file)... do I need to compile with 
jasper as well so that I can output geojp2 files, or is there some way 
to tell gdal_translate to output a .wld file for the output file?

3) My intent is to build a tileindex of the output files and serve them 
up using mapserver. I'm worried about the black "collar" that I'm left 
with around the images after I've reprojected them - will mapserver be 
able to deal with the fact that these all overlap with data from the 
neighboring tile? Can mapserver deal with tileindexes that have 
overlaps? How about tiles that aren't square in the given coordinate 
system - if I use the grid from the original orthophoto files, will it 
use those boundaries to select which tile to get the data from? That 
would be the optimal solution, if it works that way. Tell me if this is 
a question better posted to the MapServer list but I know it is gdal 
doing most of this work anyway.

Thanks in advance for any answers you can offer.

Chris



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