Re: gamma 1.0 and loss of detail
Re: gamma 1.0 and loss of detail
- Subject: Re: gamma 1.0 and loss of detail
- From: "Bruce J. Lindbloom" <email@hidden>
- Date: Fri, 22 Feb 2002 09:39:39 -0600
Carl Stawicki wrote:
>
My main point was to try and illustrate the fact that G1.0 is bad news for
>
an image, without even performing any curves or edits.
I agree completely. If you want to actually *see* the effects of what Carl
is talking about, my RGB reference images
<
http://www.brucelindbloom.com/index.html?ReferenceImages.html>
illustrate this perfectly:
DeltaE_8bit_gamma1.0.tif shows the posterization problem Carl identifies.
This scene is illuminated with a soft edged spotlight, which produces very
gentle gradations of tone (without any noise). Look at the "Dark Skin" patch
of the ColorChecker chart (upper left patch) and also the periphery where
the light falls off to nothing. You can plainly see the posterization.
Compare that to the DeltaE_8bit_gamma2.2.tif, which is exactly the same, but
with gamma 2.2 instead of 1.0. No posterization.
Compare also with DeltaE_16bit_gamma1.0.tif. This image also avoids
posterization even though it is gamma 1.0, but in order to do so, must
resort to 16-bits per channel.
Note: when opening these images in Photoshop, be sure to "Use the Embedded
Profile."
--
Bruce J. Lindbloom
www.brucelindbloom.com
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