[Radiance-general] about wxfalsecolor problem

[Thomas Bleicher]

Hallo.

wxfalsecolor does not calculate values for luminance or illuminance.
Instead it uses the Radiance tool pvalue to extract this information
from the image. I am surprised that pvalue and Photosphere come up
with different values, though. Greg is probably the best to comment
on this. I myself have never used Photosphere.

The size related popup is just gives you the option to skip the pvalue
step when the image is loaded. It can take a while (especially for large
image) and for most of the features it is not necessary.

Regards,
Thomas


On Sun, Dec 12, 2010 at 11:36 PM, Mehmedalp Tural <mtural at asu.edu> wrote:
> Hello Mr. Bleicher,
>
> I am a PhD student at Arizona State University. I learned about the
> wxfalsecolor and falsecolor2 from Radiance mailing list.
> I have a question regarding the computed luminance values. I created my hdrs
> using Photosphere and run pfilt to reduce their resolution (to run evalglare
> faster).
> I checked the average luminance of a selected region before and after
> running pfilt and the results were identical under Photosphere.
> However, wxfalsecolor computed the average luminance of the same region two
> times more than Photosphere.
> (I did not process the hdr file using any other software like Photoshop,
> knowing that even cropping would change pixel values).
> What could be the reason for this difference? Wxfalsecolor pops-up an
> attention window for large file sizes. Is there a file size limit?
> I'd appreciate your comments.
>
> Sincerely,
>
> Mehmedalp Tural
> PhD Candidate
> Herberger Institute
> Arizona State U
>