Subject | Re: Is RGB to Lab lossy? - was(Re: Lenses and sharpening) |
From | Eric Stevens |
Date | 10/06/2014 10:35 (10/06/2014 21:35) |
Message-ID | <csk43a5ksgmeitftukl861detb599ksemg@4ax.com> |
Client | |
Newsgroups | rec.photo.digital |
Follows | nospam |
Followups | nospam (1d, 12h & 51m) |
nospamNot at all. If you are going to criticise conversions to Lab on the graonds that they incur losses, then you have to acknowledge that there are other things you can do in Photoshop which are equally lossy.
In article <s7h13a1fccm418skpdorc8ea5jvm4gm40j@4ax.com>, Eric Stevens <eric.stevens@sum.co.nz>wrote:nospamEric StevensEric Stevensnospam
I couldn't see the difference at all, but then I didn't want to push the screen with excessive brightness. Instead I relied on the subtraction and the histogram to find the differences, which were almost zero.
'almost zero' is not zero.
you are actually proving my point.Eric Stevensnospam
nospam has backed off considerably from his original views but I expect that won't stop him from trumpeting them again in the future.
i have *not* done any such thing. stop lying and twisting what i say.
i have *always* said it's not lossless and it is not.
There is nothing you do in image processing which is not lossless.
straw man.
'Bad' is a value judgement. Why should your value judgement be taken any more seriously than anyone elses?Eric Stevensnospam
For some reason the conversion of RGB -->Lab has been particularly singled out for criticism in this respect.
it's a bad workflow because what can be done with an rgb->lab-rgb conversion can be done *without* the conversion and with better results.
So is editing/retouching the image. --nospamthis is a fact, no matter how much you or anyone else say otherwise.Eric Stevens
It's as lossless as anything else you can do.
it's more lossy than not doing the conversions.