Setting Exposure - Page 2 at DVinfo.net

Go Back   DV Info Net > Windows / PC Post Production Solutions > What Happens in Vegas...

What Happens in Vegas...
...stays in Vegas! This PC-based editing app is a safe bet with these tips.


Reply
 
Thread Tools Search this Thread
Old February 16th, 2008, 01:33 PM   #16
Inner Circle
 
Join Date: Jun 2003
Location: Toronto, Canada
Posts: 4,750
Quote:
Having designed various hardware encoders, decoders, input and output modules in my career, I'm stunned when the standard YUV <=> RGB equations aren't used, and aren't noted in the UI.
But there's multiple equations... :D
Rec. 601 coefficients
Rec. 709 coefficients
(There are also coefficients that correspond to the SMPTE C primaries I think.)

And if you want to do a better job, you can calculate luminance correctly.
Use the 709 coefficients, apply the saturation adjustment on the gamma-corrected R'G'B' values. You need to do this in the gamma-corrected domain to get the hue looking right.

You need to multiply the resulting values by some factor to get the correct luminance. You need to do those calculations in the linear light domain.
Glenn Chan is offline   Reply With Quote
Old February 16th, 2008, 04:19 PM   #17
Inner Circle
 
Join Date: May 2006
Location: Camas, WA, USA
Posts: 5,513
Yeah, back in my hardware days (Grass Valley Emphasys Encoders & Decoders, Model 1000, Model 1200...) we only had to worry about 601.

It wasn't SD then. It was just video. :)

Glenn, do you have a good link/reference for Rec. 709?
__________________
Jon Fairhurst
Jon Fairhurst is offline   Reply With Quote
Old February 16th, 2008, 11:39 PM   #18
Inner Circle
 
Join Date: Jun 2003
Location: Toronto, Canada
Posts: 4,750
ITU has a 3 free downloads promotion! (Yes, I get excited by stuff like that.) Take advantage of it, and download ITU-R BT. 709 for free.

Poynton's book and gamma FAQ and his website are also good resources.
Glenn Chan is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Windows / PC Post Production Solutions > What Happens in Vegas...

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 06:38 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network