Return-Path: Received: from outmail146037.authsmtp.co.uk ([62.13.146.37] verified) by media-motion.tv (CommuniGate Pro SMTP 4.2.10) with ESMTP id 5048820 for AE-List@media-motion.tv; Tue, 23 Apr 2013 20:05:34 +0200 Received: from punt10.authsmtp.com (punt10.authsmtp.com [62.13.128.91]) by punt12.authsmtp.com (8.14.2/8.14.2/Kp) with ESMTP id r3NIDr7h089285 for ; Tue, 23 Apr 2013 19:13:53 +0100 (BST) Received: from mail-c235.authsmtp.com (mail-c235.authsmtp.com [62.13.128.235]) by punt10.authsmtp.com (8.14.2/8.14.2/Kp) with ESMTP id r3NIDru5054612 for ; Tue, 23 Apr 2013 19:13:53 +0100 (BST) Received: from [192.168.1.100] (c-67-169-45-154.hsd1.ca.comcast.net [67.169.45.154]) (authenticated bits=0) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id r3NIDfn2046940 for ; Tue, 23 Apr 2013 19:13:49 +0100 (BST) User-Agent: Microsoft-MacOutlook/14.3.1.130117 Date: Tue, 23 Apr 2013 11:13:40 -0700 Subject: Re: [AE] Keying and other things From: Peter Litwinowicz To: After Effects Mail List Message-ID: Thread-Topic: [AE] Keying and other things In-Reply-To: Mime-version: 1.0 Content-type: multipart/alternative; boundary="B_3449560430_55916396" X-Server-Quench: 8d91537e-ac41-11e2-b5c5-002590a15da7 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCdyYwEUBFZNQRgX IjkJEi5bSAIjKA0K ChgGOyJ3ZX4IThh5 N0tWL1MWNVoARFZf HSJNFVZXTywxG3x3 awtSfQRUaEtNVQBo Hk5OXFNUHRtsBAIA AxoBUBxwchpGNjxz Gz8WCC5ZXEB8fEJ9 DE9WFmgHK280YWEa U0cNalIHdAJXfx4Q aE0tUSAIfGUHZH9p RwZqYjw4YiNlJXYd cSggGBoxTFcKGDF0 ThYOVTIzHUAfDzkz LhopMTb9 X-Authentic-SMTP: 61633133393137.1023:706 X-AuthFastPath: 0 (Was 255) X-AuthVirus-Status: No virus detected - but ensure you scan with your own anti-virus system. > This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. --B_3449560430_55916396 Content-type: text/plain; charset="ISO-8859-1" Content-transfer-encoding: quoted-printable > The standard AE grain removal plugin can be bit coarse when it comes to > temporal smoothing, but it's better than nothing. >=20 We recommend using our DE:Noise plugin for just this purpose=8A to help temporally smooth for keying help. However, we use optical flow motion estimation to do the temporal smoothing, which the AE grain removal plugin does not, so I believe our temporal smoothing is better at this problem. Just a thought. And I'm biased of course. http://www.revisionfx.com/products/denoise/ Pete Litwinowicz RE:Vision Effects, Inc. From: Chris Zwar Reply-To: After Effects Mail List Date: Friday, April 19, 2013 11:07 PM To: After Effects Mail List Subject: Re: [AE] Keying and other things You basically learn from difficult keys, sometimes there's no easy solution= . One thing to look at is pre-processing your footage before keying. In many cases noise reduction or grain removal can have dramatic results on your output. The standard AE grain removal plugin can be bit coarse when it comes to temporal smoothing, but it's better than nothing. Grain / noise management is really important for good clean keys. Apart from grain removal, for keylight you can try doing a hue shift to increase the difference between the green channel and the red and blue channels. This will give you a different result, but not necessarily a better result. Keylight is a difference keyer - it looks at the difference between the green channel and the red / blue channels. Greenscreens are very rarely a purely 'digital' green - most greens have a lot of red in the= m and are actually quite yellow. Apply the hue / sat filter, and then apply the levels filter so you get a histogram. You should be able to see three clear peaks in the histogram for red / green / blue. Adjusting the hue wil= l move these peaks, and shifting the hue by a few degrees will move the red peak further away from the green, and start moving the blue closer (or vice versa). Find a value that puts the most difference between the green and the red/blue channels. In SOME cases this will give you a better result with fine edge detail such as hair. I've done a few side-by-side comparisons with hue shifted green screens and they've been better about half the time. If you are hue-shifting by a large amount you'll probably want to use the keyed layer as an alpha matte for the original source. -Chris On 20/04/2013, at 2:10 PM, Jonathan wrote: > Good day to all. >=20 > I've been using Keylight to do some green screen work and, basically star= ting > from scratch, went through a number of tutorials, including three from Th= e > Foundry for Nuke but which are applicable to After Effects. All the tutor= ials, > however, are general and don't deal much with pulling difficult keys, suc= h as > shots of little girls with frizzy hair. I've gone about as far as I can g= o > with what I've learned and my results aren't very good: the hair in the > transparent areas chatters like crazy. Fortunately I'm scaling from full = HD > down to 720 X 405 so some of the noise becomes a minor problem. However, = there > is one shot that is really not acceptable. >=20 > I'm using a pre-comped layer to create a matte for the same layer below i= t, > trying everything I can but still missing it. I realize this may be diffi= cult > to answer without seeing the project, but any tips anyone might want to o= ffer > would be much appreciated. (CS 6, Keylight 1.2) Thanks in advance. >=20 > Jonathan >=20 >=20 > JONATHAN PENZNER > VIDEO EDITING =80 MOTION GRAPHICS =80 DESIGN >=20 > | STUDIO 626 345-0285 | > | CELL 818 321-2890 | >=20 > sureal@c harter.net --B_3449560430_55916396 Content-type: text/html; charset="ISO-8859-1" Content-transfer-encoding: quoted-printable
 The standard AE grain removal plugi= n can be bit coarse when it comes to temporal smoothing, but it's better tha= n nothing.

We recommend using our DE:N= oise plugin for just this purpose… to help temporally smooth for keyin= g help.  However, we use optical flow motion estimation to do the tempo= ral smoothing, which the AE grain removal plugin does not, so I believe our = temporal smoothing is better at this problem.

Just = a thought.  And I'm biased of course.


Pete Litwinowicz
RE:Visi= on Effects, Inc.


From: Chris Zwar <chris@ch= riszwar.com>
Reply-To: Afte= r Effects Mail List <AE-List@med= ia-motion.tv>
Date: Friday,= April 19, 2013 11:07 PM
To: After= Effects Mail List <AE-List@medi= a-motion.tv>
Subject: Re: [= AE] Keying and other things

You basically learn from difficult keys, sometimes there's no easy solut= ion.  One thing to look at is pre-processing your footage before keying= .  In many cases noise reduction or grain removal can have dramatic res= ults on your output.  The standard AE grain removal plugin can be bit c= oarse when it comes to temporal smoothing, but it's better than nothing. &nb= sp;Grain / noise management is really important for good clean keys.
Apart from grain removal, for keylight you can try doing a hue s= hift to increase the difference between the green channel and the red and bl= ue channels.  This will give you a different result, but not necessaril= y a better result.  Keylight is a difference keyer - it looks at the di= fference between the green channel and the red / blue channels.  Greens= creens are very rarely a purely 'digital' green - most greens have a lot of = red in them and are actually quite yellow.  Apply the hue / sat filter,= and then apply the levels filter so you get a histogram.  You should b= e able to see three clear peaks in the histogram for red / green / blue. &nb= sp;Adjusting the hue will move these peaks, and shifting the hue by a few de= grees will move the red peak further away from the green, and start moving t= he blue closer (or vice versa).  Find a value that puts the most differ= ence between the green and the red/blue channels.  In SOME cases this w= ill give you a better result with fine edge detail such as hair.  I've = done a few side-by-side comparisons with hue shifted green screens and they'= ve been better about half the time.  If you are hue-shifting by a large= amount you'll probably want to use the keyed layer as an alpha matte for th= e original source.

-Chris

On 20/04/2013, at 2:10 PM, Jonathan <sureal@charter.net> wrote:

Good day to all.
I've been using Keylight to do some green screen work and, basi= cally starting from scratch, went through a number of tutorials, including t= hree from The Foundry for Nuke but which are applicable to After Effects. Al= l the tutorials, however, are general and don't deal much with pulling diffi= cult keys, such as shots of little girls with frizzy hair. I've gone about a= s far as I can go with what I've learned and my results aren't very good: th= e hair in the transparent areas chatters like crazy. Fortunately I'm scaling= from full HD down to 720 X 405 so some of the noise becomes a minor problem= . However, there is one shot that is really not acceptable.

I'm using a pre-comped layer to create a matte for the same layer b= elow it, trying everything I can but still missing it. I realize this may be= difficult to answer without seeing the project, but any tips anyone might w= ant to offer would be much appreciated. (CS 6, Keylight 1.2) Thanks in advan= ce.

Jonathan


JONATHAN PENZNER
VIDEO EDITING • MOTION GRAPHICS • DESIGN

|&nb= sp;STUDIO      626 345-0285 |
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