[FWTools] Automatic mosaic (no white)

[Vincent Neuilly]

Hi,

Sorry for my english.

I try to do a mosaic (with gdalbuildvrt and gdalwarp). When my images
contain whites, I have to make the images list in right order, and theresult
is perfect. But can some options (srcnodata...etc.) do the job automatically
(no whites) ?

With :
 - gdalbuildvrt blablabla -srcnodata "255 255 255"
 - gdalwarp blablabla (or gdalwarp -dstnodata 0)

It almost works, except a strange thing :
http://img706.imageshack.us/img706/8500/photohp.jpg

Right-top : nodata pixels are black --> ok
Right-top ( big L ): former white is black --> ok, but with a strange big L
Bottom-left : former white is stil partially visible again with strange
colors


Is listing in right order the only way ? What are these strange colors ?


Thanks.
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