[HDRI] Scaling artifacts in Photoshop CS2 w/ Radiance files?

[Mark Banas (lists)]

I've seen this a lot before: resizing a 32-bit file in Photoshop CS2  
with their bicubic interpolator produces artifacts that look like  
"excessive sharpening halos" around high contrast details. Because of  
this, I simply stopped scaling images in Photoshop and instead use  
Photosphere (no problems).

However, I was recently perusing the Adobe user-to-user forums, and  
it was determined that the "sharpening artifacts" are only present if  
you subsequently save the file in Radiance format. It was then  
proposed by an Adobe employee that "the radiance file format code may  
have some problems dealing with extreme values." (keep in mind these  
are user-to-user forums, not developer comments).

Here is the thread in question:
http://www.adobeforums.com/cgi-bin/webx/.3bbe9c64

Now I know that Photoshop's Bicubic does some sharpening (even  
without using "Bicubic Sharper"), and that sharpening of any kind on  
an HDR file results in extreme values, but does the Radiance file  
format itself have a problem with extreme values? Or is this a combo  
of PS Bicubic and their Radiance I/O? I pretty much store all of my  
"in progress" files in Radiance format and then create "final HDR  
files" from them in EXR, so this has effected me and my workflow.

-Mark

BTW, I've also found a huge flaw in Photoshop CS2's "Merge to HDR"  
when small, bright details are moving between shots (think ghosted  
leaves in a mild breeze) - so I don't even use PS CS2 for *creating*  
HDRs anymore, but the PS CS2 "clone tool" and the plugin Flexify 2  
are pretty much indispensable for retouching HDRs, so I'm using  
Photoshop in any case.