[Radiance-general] radiance pic output

Tue, 13 May 2003 10:39:14 -0700

Hi Rob,

It is difficult to compare Radiance picture resolution to traditional 
integer images as understood by Photoshop.  Radiance uses a 32-bit RGBE 
floating-point format, which is described in an article I wrote for 
Graphics Gems II, but some information may also be found in the 
following text file distributed with the system:

	ray/doc/notes/picture.format

I recently added an option to the pvalue program to output raw 
16-bit/primary files which may be imported into Photoshop using the 
"raw" type.  Use the following command:

	pvalue -dw image.pic > image.raw

Then, import it in Photoshop as a "raw" 16-bit interleaved image with 
header.  You'll have to tell it the resolution, and ask Photoshop to 
guess the header length, which you can have it preserve in case you 
ever want to get back into Radiance format with a reverse conversion.

-Greg

> From: "Fitzsimmons, Rob" <[email protected]>
> Date: Tue May 13, 2003  10:13:41  AM US/Pacific
> To: "'[email protected]'" 
> <[email protected]>
> Subject: [Radiance-general] radiance pic output
> Reply-To: [email protected]
>
> What is the bit depth of the pic(s) that Radiance generates?
> I use ra_pict to view them on my Mac - and switch the photoshop 
> setting from
> 8 bits per channel to 16 bits per channel.
> Then when I look at the histogram, values are spaced over the entire 
> range.
> Is it producing high dynamic range images?
> Am I losing anything when I convert to pict?
>
> thanks
> Rob