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DeBayer settings

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Joe Huggins
DeBayer settings
on Aug 18, 2008 at 9:09:49 pm

Men,

What a great source you all are by the way.

We did a test render in Red Cine to ProRes HQ at half debayer and then full debayer. half was 6:1 render time, full 20:1 render. What is the difference technically and visually and which shoud be used for most final work in HD output? We also found 20:1 to be the rate for 2K and HD 1:1 (using an 8-core processor)

Also, what is a 'debayer' in short laymen's terms?



Thanks, Film Joe


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Chris Borjis
Re: DeBayer settings
on Aug 19, 2008 at 7:09:21 pm


for 1080P HD, half debayer is just fine as is.


"The DeBayer filter is used to convert raw image data into an RGB image. In a raw color image, every pixel represents a value for one basic color, instead of three as is the case for an RGB image. In order to get a real color image, the two missing colors have to be interpolated. This is exactly what this filter does."



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Joe Huggins
Re: DeBayer settings
on Aug 19, 2008 at 9:36:36 pm

Thanks. So if we were going to HD 4:4:4, it would be better to have a full DeBayer, more color depth in each pixel? Does half mean 4:2:2, or what 'half' of 3 colors does it represent?

Thanks, Film Joe


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Chris Borjis
Re: DeBayer settings
on Aug 20, 2008 at 7:50:26 pm


no, I believe it's for resolution purposes.

for editing anything bigger than 1080P (2k or 4k) should probably
be full debayer.

anything more is overkill for HD.



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gary adcock
Re: DeBayer settings
on Aug 20, 2008 at 8:12:51 pm

[Chris Borjis] "for editing anything bigger than 1080P (2k or 4k) should probably
be full debayer."



reserve the full debayer for full rez imagery only - and since there is no 4K in FCP nothing more than 1/2 debayer is really needed. This will cut your rendering times by about 2/3 also


gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD




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Joe Huggins
Re: DeBayer settings
on Aug 20, 2008 at 9:44:19 pm

Gary,

Thanks, that's very helpful. Oh, did my render time estimates seem correct(20:1 and 6:1)? Are there any other settings that reduce the render times from Red Cine? I read on the Cow that an Avid edit, imported to HD in a 2:1 ratio, which seemed very quick for an Avid DNxHD project. Here's the cow thread that linked to a user's 48hr film award:
http://library.creativecow.net/articles/reeve_dylan/48hours.php

Thanks, Film Joe


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gary adcock
Re: DeBayer settings
on Aug 20, 2008 at 11:11:52 pm

joe

with RED it is all about the CPU/ GPU/ RAM combo in your computer...

if you want to go faster the only thing you can do is add hardware.

did you see that AJA released the RED compatible Driver- meaning that you can cut in the proxy files and still maintain quality? The card is doing what looks to be 1/2 debayer (still testing) for a 2K output.
That means using the proxies and hitting "play" to get what you are doing in RedCine.

Look into RedRushes- very sweet little app and I now prefer it to RedCine


FYI did you read Dylan's note at the bottom of the page that commented that he was hoping to do an HD version from the same cut- so that 2:1 import time for 1K 8bit conversion for an SD delivery is about correct it is the other 5 steps to get audio and TC into the Avid that just sucks.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD




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Graeme Nattress
Re: DeBayer settings
on Aug 21, 2008 at 1:31:19 am

Full debayer is necessary to extract 4k resolution for 4k footage. It also makes for the best 2k when scaled down. However, if you're going direct to 2k, the half debayer is optimized to extract to the full 4k and scale down to 2k in one step, and hence is much quicker. If you're just going to 2k, then the half is fine, but you may get a percent or two more quality going the full debayer + scale route.

- http://www.nattress.com - Film Effects and Standards Conversion for FCP


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gary adcock
Re: DeBayer settings
on Aug 21, 2008 at 12:30:14 pm

Thanks for that Graeme....


Since the vast majority of users are looking at HD finish and SD delivery for most of their content I have followed that guideline.

If it is a 1080 ProRes edit I have found that most cannot see the difference between the full and the half debayer.

If you are planning a 2K / 4K DPX conform go full debayer and for Crimson / Scratch workflow it does not matter since Scratch handles Full debayering in realtime on output.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD




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Joe Huggins
Re: DeBayer settings
on Aug 21, 2008 at 3:03:17 pm

Gary, I'm having a 'duh' moment and my tech staff is out today. I've found web posting about Red Rushes, but I can't seem to find the site to purchase the software itself. Can you provide the right link?

I have noticed many people posting their problems with Rushes, but you like it better than Red Alert you say?

Joe

Thanks, Film Joe


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Russell Lasson
Re: DeBayer settings
on Aug 21, 2008 at 6:34:08 pm

It's part of the Red Alert download.

-Russ

Russell Lasson
Kaleidoscope Pictures
Provo, UT


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gary adcock
Re: DeBayer settings
on Aug 22, 2008 at 3:15:41 pm

[Joe Huggins] "Gary, I'm having a 'duh' moment and my tech staff is out today."

what russell says.

RedRushes is installed as part of the new versions of RedAlert. Take some time to get to know it
it is really a great workflow tool that Graeme & the RED team made for us.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD




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Joe Huggins
Re: DeBayer settings
on Aug 22, 2008 at 7:09:20 pm

Gary,

Thanks, I did figure out that it is part of Red Alert. We'll review in more depth. Is there any short 'white paper' on the features and techniques of Red Rushes? I could not find much written about it or for it.

Joe

Thanks, Film Joe


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Ed Yonaitis
Re: DeBayer settings
on Aug 26, 2009 at 12:26:54 am

Nobody has answered what the difference is between Full and Half Debayer. I could be wrong, but it seems like Full Debayer would sample and average 4 pixels from the 4k source for every 1 pixel of the final 2k image, whereas Half Debayer would just select 1 pixel out of every 4 in the source to get the final pixel.

While the difference would normally not be noticeable, it would theoretically be very important when processing footage with a high ISO or low light, where there is a lot of noise in the source. By averaging out 4 pixels of random/noisy information, a more accurate/less noisy pixel could be created.

This is all speculation. Does any one know if it works differently than this?



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Joe Huggins
Re: DeBayer settings
on Aug 26, 2009 at 1:17:11 pm

Thanks, surprised you found this year old thread.

Thanks, Film Joe


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Joe Huggins
Re: DeBayer settings
on Aug 21, 2008 at 1:50:14 pm

Thanks for taking the time to reply. We use your famous filter pack in Color. I guess this is like getting your 'autograph.' smile

Joe

Thanks, Film Joe


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Graeme Nattress
Re: DeBayer settings
on Aug 21, 2008 at 2:44:16 pm

Thanks Joe.

Graeme

- http://www.nattress.com - Film Effects and Standards Conversion for FCP


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Uli Plank
Re: DeBayer settings
on Aug 30, 2008 at 5:30:57 pm

Hi Graeme,

someone recently wrote at reduser that you'll see more of a difference in low-light situations. Would this be the case even when going directly to 2K or only with 4K (plus downscaling after decode)?

TIA,

Uli

Director of the Institute of Media Research (IMF) at Braunschweig University of Arts


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Joe Huggins
Re: DeBayer settings
on Aug 21, 2008 at 1:55:41 pm

Gary, thanks once again. No, we have not looked recently on the driver update. That's good to know.

We'll review the Red Rushes for sure. We see many producers who use Red Cine rendered by a camera tech's settings on location, who do not follow the usual 'dailies' to 'finals' approach with Red. They use it like an HD camera, not a 'negative' camera, if you get my analogy. You guys are the best! Joe

Thanks, Film Joe


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Mike Most
Re: DeBayer settings
on Aug 23, 2008 at 2:32:20 pm

The Kona card/driver do not have anything to do with debayering. They get their input from Final Cut's output. If you're looking at proxies in Final Cut, there is no debayer going on at all, other than the "quick debayer" to turn the RAW information into an RGB image. Not to mention that Final Cut can't really play a 2K proxy at best quality in real time to begin with, you must set the playback quality to something lower, like "medium" or "low" (or dynamic, which will select one of those two depending on your computer's capabilities).

As far as I can tell, the only things the new Kona driver are doing are slight rescaling and cropping in order to get the image to a standard video frame size. That's it. It might look pretty good, but if you look closely, you'll see all kinds of jaggy edges and other artifacts as well, not to mention a softer image than you should be getting (if you're using proxies, not necessarily if you're using converted files).



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William Zitser
Re: DeBayer settings
on Jan 24, 2010 at 11:17:56 pm

Now I really don't understand. A red file that was 1.14GB, when converted to 1080 using Full Res it turned out 404MB, but when I did it again with Half Res(Standard) it came out 623MB.
Does that make any sense?

Thanks,

W.


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Fabio Airaudi
Re: DeBayer settings
on Jul 1, 2014 at 1:24:08 pm

You got the point! Your 400/600MB files are compressed(you don't say which codec, it doesn't matter).
Debayering at full or half quality makes a difference, e big one, even if in some case, with poor monitoring tools, and for a not so expert eye, ecc... it couldn't be noticed.
The file size difference is due to the fact that the worst quality of the data debeyered at half quality are far more harder to manage for the compression algorithm, and so you got a bigger (and probably worst) output


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