[gdal-dev] gradient alpha transparency bands for edge-blending in gdal_merge

[Jean-Claude Repetto]

On 01/02/12 05:55, Jeffrey Warren wrote:
> I'm using some images with blurred edges (like
> http://tinyurl.com/6r2s3z4) to mosaic a larger geotiff with gdal_merge,
> but it doesn't respect transparency that's not either 0 or 1. Is there
> any way to achieve this without coding my own merge tool?
>
> This is what results: http://tinyurl.com/7xckw98
>
> The command i'm using (gdal 1.7.3 on ubuntu 11.10) is:
>
> gdal_merge.py -n 0 -o warren-township-geo.tif 47539-geo.tif
> 47543-geo.tif 47547-geo.tif
>
> More detail on this issue is here:
> https://github.com/jywarren/mapknitter/issues/15#issuecomment-3326956
>
> I'd appreciate any tips, and I am wondering if I can contribute if this
> functionality does not exist already.
>
> Jeff

Hi Jeff,

I am not sure it will solve your problem, but you should try gdalwarp to 
merge your files.
gdal_merge.py is only an example program to show how to use the Python 
API. The correct tool to merge files is gdalwarp.

Jean-Claude