Magic Bullet deartifactor - how to
 

I've recently bought Magic Bullet Editors v 2 for Vegas 7 and am very interested in using their chroma cleanup plugin - deartifactor. When I activate it I see three presets - 4.1.1; 4.2.2 and 3.1.1 but I am in PAL land 4.2.0. There is no preset for that and I don't see much in the way of tutes on the subject. Can you tell me how to use it on a PAL job please. The source images are PAL Dv.Thx

some info
 

what does the deartifactor do? seriously?

Vegas' chroma blur effect will basically do the same thing, and with much much better render times.

Wow...thats a shock to the system. If you are right, hardly seems worth having designed it.

Anyway, I want to try it out so can you tell me whats going on with the presets...there's no 4.2.0 settings. What am I missing? I want to test its chroma clean up [in deartifactor], make an avi then work on it in Fusion 5 in 4.2.2 space.

Whether it was worth designing it or not is not for me to call (though it must have been if people are paying for it), but as far as I can tell, Vegas' chroma blur does the same thing.

First of all, no plug-in in the world is ever going to extract enough color information from DV video to give you a true 4:2:2 color space. Think about it: you're talking about adding color resolution in post. Can you add luma resolution in post? If you can, tell me how... I'm going to go convert all of my DV stuff to 4k @ 4:4:4. ;)

The best the Magic Bullet deartifactor can hope to do is to smooth some of the chroma blockiness in 4:2:0 or 4:1:1 color space. Red Giant says that their deartifactor uses a "proprietary engine" to accomplish this smoothing. But if you think about it, blurring is about all that can be done. You can't add pixels that weren't there when the camera threw them out to compress the original footage. :) I guarantee that if you try both the MB deartifactor and the Vegas chroma blur, you'll get pretty much the same thing. Either one of these techniques will help with compositing and chroma key and things like that, but only a tiny little bit. There's no real "magic" plugin that can fix everything in post. :)

Now, for the presets... The page that John linked to explains that the DV/HDV preset compensates for 4:1:1 or 4:2:0. So if your footage is 4:2:0, that's the one you'd want to use.

Then try using chroma blur to do the same thing and see if it doesn't render faster. :) The Vegas effect calls it what it is and doesn't get your hopes up. In addition, you have more control over the amount of blur with Vegas' effect.

Ths was supposed to have gone out 24hrs ago...maybe I messed it up cos it was 3 or 4am!

"First of all, no plug-in in the world is ever going to extract enough color information from DV video to give you a true 4:2:2 color space."...point taken but I want to try to extract as much out of these images as possible.

I did a test on MB deartifactor using the 4.1.1 setting. It sure did take a l-o-n-g time and I don't see any difference at all. Maybe because it shoufl have been 4.2.0 but there is no setting for that, only 4.1.1 Has anyone out there used the deartifactor in PAL? can you see 4.2.0 in the setting cos i sure can't.

The biggest reason i want to clean up the chroma is for DVD burn - to sharpen the image as much as possible while retaining clean colour.

Again, according to (the maker of Magic Bullet) Red Giant's own web site, the DV/HDV setting (4:1:1) is for use with both 4:1:1 and 4:2:0. It is supposed to compensate for chroma blocking in these color spaces, but the effect is relatively minor. And for the record, all things Magic Bullet will take 16 eons to render. :)

Try Vegas' chroma blur! It renders quite a bit faster, and you have more control over it. At the max settings, the difference is quite visible--especially with blocking on red and orange objects.

Thx, I'll try that tonight Jarrad.

Odd that 4.2.0 isn't indicated but thx for letting me know.

I am looking at the Chroma Blur window - there appears to be no preview, so it's all a suck and see is it?

Without sounding like a slouch, do you have any recommended settings or is it entirely dependant upon the source material?

Keith Kolbo's tutorial "Using Chroma Key and Chroma Blur in Sony Vegas" tutorial at http://amediaprof.com/content/index....d=16&Itemid=59 will walk through how to do this properly and yes, it is dependent on the source material.

Thx a bunch for the link Mike - I'm headed there now.

The chroma key info is interesting although the chroma blur stuff is a bit on the sparce side. Thx anyway.

There's really no need for a tutorial as far as chroma blur goes. You just adjust the sliders for horizontal and vertical blur until your "jaggies" are either gone or as smoothed as you can get them. It's a very simple effect.

I'm not sure why you're not seeing a preview, either. The footage previews in the preview window just like every other effect.

If you're expecting a really massive improvement, you may not be able to get it. Even with chroma smoothing, your footage was written to tape at 4:2:0, and there is no way to convert it to a higher-resolution color space because the additional picture information simply doesn't exist.

With that in mind, realize that there are limits to what can be done with the chroma blocking. As I was saying earlier, the effect is most apparent/beneficial when there are high-contrast reds and oranges in the shot--but it can still be very beneficial with chroma blocking issues that come into play with chroma key footage.

What kind of problem are you having with chroma blocking, anyway? I don't think we've ever really addressed the particular situation you're dealing with. Blocking is usually only an issue when keying or when reds (which the DV codec doesn't handle well) are visibly blocky in regular footage. You seem to be dealing with neither of these situations. You mention cleaning up the footage for DVD, but what do mean by that exactly? Give us a precise description of what it is you want to try to fix.

Ok - I read somewhere that cleaning up chroma can increase the apparent sharpness for a DVD burn...did I get that wrong? Thats all I'm trying to do - maximize the output.

If anything, chroma blur will slightly decrease sharpness, at least as far as the chroma part of the image is concerned. Blur and sharpness are opposites. :)

I wouldn't recommend chroma blur as the kind of thing you'd use as a matter of course. It's really only needed in certain situations, like those I explained earlier. I'm thinking that the chroma blur effect is probably previewing perfectly well, but that the footage you're applying it to maybe doesn't really need it. If there are no obvious chroma-blocky areas in the image, then you won't really see much difference, if any.

As far as maximizing the quality of your images for DVD goes, it's hard to offer suggestions when I'm not sure what you'd consider to be optimal. Is there anything about your video's look in particular that you're trying to fix? You can't really get to an optimal place unless you have a very clear idea of what "optimal" means. Does that make sense?

Ok maybe you're right thats there is nothing blocky in the images so Vegas Chroma Blur won't pick it up...BTW, should there be any sliders in the MB deartifactor for DV/ There isn't any here.

The DVD saga is this - loss of sharpness and contrast from what I see is going on in the edit. If i switch to the external monitor [a Tv] during editing, sharpness is great. Thats with no CC or Fx. By the time I use the default settings in DVDA 3 for PAL, two things have happened - sharpness takes a dissapointing hit and so to does contrast - a noticeable flatness has veiled itself over the entire program. So they are the things i am trying to clean up.

No, the settings aren't adjustable in the MB deartifactor--which is why I was saying you have more control with Vegas' chroma blur.

OK, now we're cooking with gas. :)

Some of that is just due to the fact that the video has been highly compressed, so there's not too terribly much you can do. You might try rendering your project to an .avi intermediate before going to MPEG and then boosting sharpness and contrast ever so slightly before rendering using a DVDA template. It may take some trial and error, but if you can find a "sweet spot" where you're not adjusting those two things so much that you go to far with them, but also making sure there's enough of an adjustment to make a difference, then you might be able to improve your image a bit. But again, DVD video is extremely compressed, and that means you're throwing out huge chunks of the original image data. That's just the nature of the beast.

Someone else might have better suggestions.

On the chroma blurring side of things...

I find that using a median filter (set to around 2) on the chroma of a blocky DV section of footage gives a better result than using a chroma blur.

I am not sure how you would do this in Vegas, but I achieve it in After Effects by simply applying the median plug-in to a blank layer, make that layer an adjustment layer and then set its transfer mode to 'color'.

Works much better then MB deartifactor (really!) and like Jarrod pointed out with regard to 'chroma blur' you have much more control over the effect.

Don't do it!

Do your MPEG2 renders in Vegas - you'll get much more control of the results. The defaults in either program aren't that great.

Check out Edward Troxel's excellent newsletter at www.jetdv.com for some basic guidance on this, Vol. 1 #7 has the info. Also look at Vol. 4 #1. Note that Edward's bitrate table is for NTSC video at 29.97fps, with PAL at 25 you have a few more bits to give to quality.

Try it - I think you'll like the results.

There are tricks you can use to improve the chroma. One of them is chromaticity-style interpolation (you intepolate in a chromaticity-style color space instead of a chroma-based color space). You can see the difference between these three images (they have 300% zoom to make things easier to see):

http://glennchan.info/articles/techn...e-original.png original
http://glennchan.info/articles/techn...romaticity.png chromaticity-based interpolation
http://glennchan.info/articles/techn...a/e-chroma.png chroma based interpolation

It just so happens that all chroma-based interpolation has a tough time with red lines on a black background. No 4:2:2 codec that I'm aware of can do it without visible artifacting.

In more real world situations, those small chroma errors may not be a big deal. Red lines on a black background are exceedingly rare, and your footage will likely go back to 4:2:2 or 4:2:0 anyways (and they will get screwed up again).