On Sat, 24 Mar 2012 12:08:17 +0000, Pete A wrote:
Actually, Preview is a crap image scaler. Up to and including OS-X 10.5
(Leopard), image scaling in Preview, Safari, Finder thumbnail view, and
other applications is not gamma corrected. I don't yet know if this
error has been fixed in later versions of OS-X.

http://www.4p8.com/eric.brasseur/gamma.html

Thanks for that link! It's a very nice exposition of the problem, with
good examples. I think that this situation has started to improve over
the last couple of years (when I first heard it discussed.) In
particular, Preview in OS-X 10.7 (Lion) passes the grey-Lama test with
flying colours. Sadly, none of the web browsers I have on this system
(Safari, Firefox, Chrome) do it properly, though. I guess that in
browsers, speed trumps correctness.

Unfortunately, the image scaler in NX2 is not gamma corrected either,
therefore I have no means of downsizing an image without losing quality,
irrespective of the JPEG compression level.

What does NX2 do if you do the scaling on the RAW/NEF image (which is
linear), rather than a JPEG?

Rather than faffing around trying to find proper image scaling software
I'll experiment with OS-X Lion - if its version of Preview has an
accurate image scaler I shall be very pleased indeed.

Prepare for slight/moderate pleasedness...

Cheers,

--
Andrew