[Radiance-general] Falsecolor tricks

[Greg Ward]

Hi Mike,

You probably need to hack falsecolor if you want it to appear in the right place with the legend and everything.  Look for pextrem and think about how you would replace it with something that pulled out the desired pixel value like so:

	$xpos = 250
	$ypos = 300
	$lumval = `ra_xyze -o orig.hdr | pcompos -x 1 -y 1 - -$xpos -$ypos | pvalue -h -H -b -d`
	psign -s -.15 -a 2 -h 16 $lumval | pcompos falsecolor.hdr 0 0 - $xpos $ypos > composite.hdr

The ra_xyze command is to undo any exposure setting before passing on to pcompos to pull out the desired pixel, and is unnecessary and inefficient if your picture hasn't been processed by pfilt or anything that added an EXPOSURE= line.

I hope these hints get you going in the right direction.

-Greg

> From: Michael Martinez <michael at coolshadow.com>
> Date: September 24, 2013 1:25:14 PM PDT
> 
> Hi All - 
> 
> I'd like to make falsecolor stamp an image with a value for a single pixel of my choosing (say at 250, 300 in a 1000px x 700px image), similar to how -e works. This is to show irradiance levels changing at a given point in a sequential animation. Anybody have a trick to do this, or something like it? 
> 
> Thanks very much,
> Mike
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