[Radiance-general] Fwd: errors from hdrgen

[Martin Matusiak]

Ah yes, I had been meaning to try the camera calibration technique but I 
hadn't come around to it. It turns out to be very useful. But I still have 
some issues. I took in all 13 pictures of an indoor scene looking out the 
window for the calibration. I then had to remove the darkest and the lightest 
of them to get a hdr image. That leaves about 8 images and I get a hdr image 
but there are errors in the conversion process.

The resulting hdr does not look very good, first of all the alignment 
algorithm always distorts it like crazy. The images were taken with a tripod 
so they should be reasonably well aligned but the algorithm moves them all 
over the place. So I disable that. I tried setting -g to kill the ghosts but 
that totally messed up the color balance of the image.

If I only turn off the alignment algorithm, the image still looks very 
green/brown however. I take it this isn't supposed to happen? I toggle the 
exposure adjustment but it makes no difference.

Pardon my ignorance, but is the hdr image supposed to look a lot like the 
original? Is it a bad sign when the color balance is all wrong? 

The images I took are enclosed. They were taken sequentially from lowest to 
highest exposure, -2 to 2 in 1/3 steps. White balance was set to "overcast" 
and should be the same for all, taken within 1 minute of each other.

url: http://www.juventuz.com/_temp/for_calibration.tar.bz2

If you have more luck with them, I'd love to know what options were used in 
the conversion process.


Martin



On Thursday 10 June 2004 17:23, Greg Ward wrote:
> conversion of digital pictures to
> Radiance?