[Radiance-general] Re: falsecolor and textlabels question

[Greg Ward]

Forgot to forward this to the group.  Maybe it's of interest to someone.

-G

Begin forwarded message:

From: Greg Ward <gward at lmi.net>
Date: March 19, 2004 8:58:49 AM PST
To: "Pierre-Felix Breton" <mail_lists at pfbreton.com>

Hi Pierre-Felix,

I think I understood your question, and I answered it as best I could.  
There are exactly two extrema points in any data set, so you won't get 
more than this using falsecolor (or any other tool).  However, you can 
get a legend corresponding to other values using the -cl or -cb options 
of falsecolor.  If you want actual numeric labels superimposed on your 
image, you have to use the trick I explained with ximage, which 
unfortunately works only on certain X11 servers.  Failing that, you 
would have to do a bit of programming with the C-shell to get place 
labels in your image.

Here is an example that works within a C-shell:

% ximage -olp -e auto picture.hdr | ( echo -n 'pcond picture.hdr | 
pcompos - 0 0' ; rcalc -o ' "\\!psign -h 12 ${$1}" ${$2} ${$3}\' ; echo 
'| ra_tiff - labelled.tif' ) | csh -f

Once ximage is up, type 't' at the places where you want it to report 
the luminance.  Obviously, you'll have to substitute both occurences of 
"picture.hdr" with your HDR image name.  The output is put in the TIFF 
"labelled.tif"

-Greg

P.S.  Why on Earth are you using Mental Ray?  Don't you LIKE long, 
incomprehensible command lines?

> From: "Pierre-Felix Breton" <mail_lists at pfbreton.com>
> Date: March 19, 2004 3:41:15 AM PST
>
>  Hi Greg,
>
> Now that I relook this ,I think I did not expressed myself correctly:
>
> I am using the -e switch of the falsecolor utility. The text labels 
> overlaid
> on the drawing (extrema points) are really useful for me.  I would 
> like to
> add more of theses labels though and wonder if it is possible somehow
>
> Regards,
>
> Pierre-Felix
> Note:  I must say that I don't generate the irradiance data out of 
> radiance.
> I use mental ray that saves a pic file with the data I want so I am
> essentially looking for 2d tools.