[Radiance-general] Rcalc if(cond,then,else)

[Humann Chris]

Dear list,

I'd like to use Pvalue to pipe an image in to Rcalc and divide each  
pixel's Red value by its Blue value.  If the latter ratio is greater/ 
equal to .6 then I'd like make the given pixel white and if not then  
black.  I'm using the following Pvalue command:
pvalue -o -h -H image.hdr

The if(cond,then,else) function is eluding me

Thanks as always.

Chris

Christian Humann ~ Associate
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On May 29, 2012, at 3:49 PM, Guglielmetti, Robert wrote:

> Yeah Randolph, this is very cool, and a nice application of HDRI in  
> the real world. Might be worth posting a link to this on the HDRI  
> list as well.
> ________________________________________
> From: Eddy Santosa [mceddysantosa at gmail.com]
> Sent: Friday, May 25, 2012 4:56 PM
> To: Radiance general discussion
> Subject: Re: [Radiance-general] OT: A study of LCD display luminance
>
> Randolph,
>
> Thank you very much for sharing nice study. It's interesting  
> results. Last time, I relied on the LCD manufacturer brightness  
> specs or nit number to model and I was not sure whether it was a  
> correct method.
> Additionally, in your first image, may i know how you set the  
> brightness setting in your computer? was it in maximum/100%  
> brightness setting?
>
> Thank you,
>
>
> Eddy Santosa
>
>
>
>
> On Fri, May 25, 2012 at 3:22 PM, Randolph M. Fritz <RFritz at lbl.gov<mailto:RFritz at lbl.gov 
> >> wrote:
> For a simulation, I wanted to include some LCD displays.  Problem  
> was, I didn't know how bright they actually were.  So I did an HDR  
> photographic study of mine.  I thought some of you might be  
> interested, so I've put it up online.  If you are interested, you  
> can see the results here:
> http://elad.lbl.gov/index.php/Interior_Applications/Display_Luminance/L226W
>
> --
> Randolph M. Fritz
>
>
>
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