[gdal-dev] gdal2tiles.py issue

Jerl Simpson jsimpson at wxtrends.com
Thu Apr 21 11:50:28 EDT 2011


Hi guys:

I posted a similar question a week or so ago, but have slightly
different information that might help me reach a solution.

I'm using gdal2tiles.py to tile up an image for google maps.  It works
great right up to the 180th meridian.  That's where it introduces a
transparent strip on the edge of the image.
Here's the original image:  http://maps.craniumjuice.com/TMXF.png
Here's a screen shot showing the gap:  http://maps.craniumjuice.com/gap.png

If I slice up the original file using imagemagick, there's no gap at
the border. It takes forever and I didn't get a screen shot.  Plus the
Y values are flipped so it doesn't overlay properly, it was just a
proof of concept that the full image is really there, it definitely
is.

Any ideas what could be causing the transparent strip at the end?

This gdal2tiles.py command gives me the gap from the screen shot:
gdal2tiles.py -s EPSG:4326 -z 2 TMXF.png .

I also tried treating it as just a raster file and got really bizarre results:
gdal2tiles.py -p raster -z 2 TMXF.png .

If I use an image that's the size of the original data, I don't get
all the images.

If I use gdal_translate to make it a 4096x4096 image, it gives me all
the tiles, but they're not right either.  That gives me a 64x64 image
with the rest of the 256x256 of the image transparent.
http://maps.craniumjuice.com/1.png

I'm sure there's some setting or something I can do to get the full
image tiled up with out adding these transparent stripes around the
tile, I just can't find it.

I'm using GDAL 1.8.0, released 2011/01/12

I appreciate any insight you might be able to give.

Thanks

Jerl


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