[gdal-dev] GDALwarp creates some darker images after update from 1.7.0b2 to GDAL 1.11.0

[Marcel Blom]

Because of some problems with GDAL 1.7.0b2 in FWTools 2.4.7 I upgraded 
to GDAL 1.11.0 in the latest OSGeo4W distro. This solved some issues I 
had, but introduced a really annoying one and what ever I do I can't get 
rid off it. I hope someone can help me out. If BTW I try to go back to 
GDAL 1.7.0b2 with FWTools the problem is still there, so I guess it's a 
(new) driver/DLL update issue.

My problem looks exactly like this post... GDAL TIF to JPG Creates Dark 
Image 
<http://gis.stackexchange.com/questions/101393/gdal-tif-to-jpg-creates-dark-image> 
Only that I don't use JPG. And I use GDALwarp. And not all target files 
have the problem. Most target files look OK. And I only see it with 
Aerial Photo like sources. With vector like raster sources I don't see 
the problem. So when reading the other post I thought it had to do with 
a mask/alpha channel or something, but I can't see this in the source. 
And whatever option I test, the problem remains.

I already created a post here : 
http://gis.stackexchange.com/questions/114526/gdalwarp-creates-darker-target-image-sometimes
But I had no final answer... And I think this is the right place to ask.

Here are two screenshots. One from the source (Tiff) and one from a 
intersection of four target files (Tiff or BMP)

Section of Source : 
https://www.dropbox.com/s/gy2tu0h8dufv41o/Source.jpg?dl=0

Intersection of four Target files : 
https://www.dropbox.com/s/av7mdj8ivx3zgsl/Target.jpg?dl=0

The source I use is 8bit/channel RGB JPEG. And the merged Tiff is 
8bit/channel RGB.
I tested almost all options in multiple actions in my workflow. So 
cutting the source with gdaltranslate in smaller parts for editing. 
Building a VRT with gdalbuildvrt and cutting into final parts with 
gdalwarp which will show the problem.

I started with the -b 1 -b 2 -b 3 option in my gdalbuildvrt action, but 
GDAL crashes here... (?) I also tested other options that might have 
something to do with the problem... -nomd -co ALPHA=YES/No -co 
PHOTOMETRIC=RGBA/RGB -setci, you name it...

I checked good and bad source and target areas with gdalcompare and 
gdalinfo, but I saw nothing strange...

I'm now thinking of resetting GDAL driver settings if that is possible..(?)

Has anyone seen this before? Can anyone give me a hint..?

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