Hi all,
I'm a bit puzzled by the result of applying fisheye_corr.cal to an
fish-eye image.
I have a simple example:
I created a fish-eye image with a sun at 5 degree altitude and kept the
sky black (just the sun). Let's assume now this image is
equi-solid-angle and we want to transfer it to a equi-distant (-vta).
For this I applied /pcomb -f fisheye_corr.cal -o fisheye.hdr >
corrected.hdr/.
In the next step I counted the amount of pixels for the sun in the two
images. They are exactly the same! What has changed is only the
position in the image. Neither the size of the sun nor the luminance has
changed.
But: The difference between the solid angles of a pixel at 85° from the
center between equi-solid-angle and equi-distant projection is around
20%! (in my example the solid angle per pixel for a 5000x5000 image at
85° is: 3.2e-7sr vs 2.58e-7sr)
I would have expected also a change in size, accounting for the
difference in solid angles per pixel for the different projection
methods, the luminance of course should be the same.
Am I doing sth. wrong?
thx for the help.
Jan
_______________________________________________
HDRI mailing list
[email protected]
https://www.radiance-online.org/mailman/listinfo/hdri
