ADOBE AFTER EFFECTS: Forum Expressions Tutorials Creative Cloud

Getting rid of white backgrounds

COW Forums : Adobe After Effects

<< PREVIOUS   •   FAQ   •   VIEW ALL   •   PRINT   •   NEXT >>
anita sancha
Getting rid of white backgrounds
on Jan 3, 2011 at 5:11:54 pm

How best to get rid of white backgrounds.

I have 50 different fish all chasing this one. Some are stop motion crayon drawings made by children filmed on white paper. Some are captured being drawn on screen using Painter in real time and have white backgrounds. But I want to know if I can remove the white background around these fish, especially when there are many on the screen at the same time, (a masking nightmare,) I have tried using a difference key with a white layer, autotraces, I have tried mattes and end up with a semi transparent fish. I want to add a water background to these many fish. So the entire fish need to be opaque even if they are partly white. Maybe I was on the right track with some of my trials, but would welcome some help thanks

CS4 so no rotobrush.



Thanks for all your help
Anita Sancha.

http://www.anitasancha.co.uk


Return to posts index

Kevin Camp
Re: Getting rid of white backgrounds
on Jan 3, 2011 at 6:13:17 pm

i would probably do this in photoshop.

photoshop's select>color range tool can be pretty effective at selecting white. using that to create a layer mask, then using curves or level to tweek the mask should give good results. also (after applying the mask) you can use layer>matting>remove white matte or defringe to help clean the white fringing/halo up.

also, you can often use a specific rgb channel as a mask -- create a mask for the layer, then goto channels and see if any of them would make a good mask, then copy/paste that channel into the layer mask channel. tweak the matte from there.

in after effects, you might try the luma key effect, but i doubt that it will yield much better results than what you've tried thus far.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW


Return to posts index

Roland R. Kahlenberg
Re: Getting rid of white backgrounds
on Jan 3, 2011 at 7:02:49 pm

You can use the Multiply Blending Mode if you don't need an Alpha Channel for the fishes. If you want an Alpha Channel OR if there are white areas within your fish then you'll need to create a matte for the fish.

You can try the Color Key and use the colorpicker on the white area. a value of 33 on my end did a decent job. Then use Matte Choker to clean up the edges. The default setting for Matte Choker did a decent job.

Another method is to apply Effect>Stylize>CC Threshold. A value of 245 for threshold was used to create a silhoutte effect for the fish. Then apply Effect>Channel>Shift Channels and set Take Alpha From to Luminance. Then apply Simple Choker with a setting of -3 to clean up the edges.

Use this layer as a track matte for the original fish image.

For both methods, the Paint tools; eraser and brush may come in handy to clean up certain spots.

It's good to have more than one technique handy as one may work better than the other on specific issues. I keep thinking there's another useful method but I just can't recall it right now. Hopefully these will work for you.

When dealing with stills, remember to render out the images after keying and BEFORE animating so that you're not keying more than the one frame that you need for stills.

HTH
RoRK

AE Training in South East Asia. AE templates for sale and rental. Click here for more


Return to posts index


Chris Wright
Re: Getting rid of white backgrounds
on Jan 3, 2011 at 7:54:05 pm

procedural matte keyer.

it's a combination of luma and chroma. I originally created it for skies to key out clouds, but it works perfect for your fish, enjoy.


matte controls adjustment layer
http://www.megaupload.com/?d=AA6X17LF

http://technicolorsoftware.hostzi.com/


Return to posts index

anita sancha
Re: Getting rid of white backgrounds
on Jan 3, 2011 at 8:16:20 pm

Thanks guys I will need a little time to sort these different trys out... Most appreciated.


CS5 ?? would the rotobrush have made a huge difference to this project.?

Thanks for all your help
Anita Sancha.

http://www.anitasancha.co.uk


Return to posts index

Michael Szalapski
Re: Getting rid of white backgrounds
on Jan 3, 2011 at 10:15:57 pm

Rotobrush is more useful for moving objects. You'll get a similar effect with the magic wand in Photoshop on a still object like this. Heck, even ye olde Autotrace might do the trick.

- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')

No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.


Return to posts index


Roland R. Kahlenberg
Re: Getting rid of white backgrounds
on Jan 4, 2011 at 12:11:53 am

YUP! Autotrace is another option. I tried out the fish with these settings -
Channel - Luminance
Tolerance - .1
Minimum Area - 2
Threshold - 90
Corner Roundness - 1

When Autotrace is not set to create a new layer (when the Apply to new layer option is not selected), the masks that Autotrace creates are applied to the layer itself. Further the masks are created, have their Mask Modes set to None.

You may find that extraneous masks are created during the Autotrace procedure. Creating outlines such as this exercise is, will result in the mask that you want to use to be the last mask in the list. Simply select the said mask and change it's Mask Mode to Add. You may safely delete the unwanted masks.

When you need to use multiple masks to create a desired effect, it is useful to start working either from inside out or from outside and work your way inwards. The former seems to be the technique employed by the Autotrace algorithm.

Apply Effect>Matte>Simple Choker with a value of about 3 to clean up the edges. You may also feather the mask to create a softer edge. The downside to Autotrace is that you can't save it as a preset although it remembers its previous settings.

HTH
RoRK

AE Training in South East Asia. AE templates for sale and rental. Click here for more


Return to posts index

Simon Giles
Re: Getting rid of white backgrounds
on Apr 18, 2012 at 4:44:04 pm

Hi Chris,

I have a similar situation and was wondering if you could please re upload your 'matte controls adjustment layer' file?

I am creating miniature watercolor animations and would like to bring them into after effects and layer them into the same composition.

I have been playing around with frame blending and the problem I have is that if I want to move one of my watercolor animations around the frame I can see the edges of the animations frame because it is not pure white. It is very close to pure white but not exactly. I think your file might be of help!

I don't need an alpha channel, just a way of masking the edges of my composition.

Hope to hear from you,
Simon
:)


Return to posts index

Chris Wright
Re: Getting rid of white backgrounds
on Apr 20, 2012 at 12:08:19 pm

add a keying-linear color key effect
eyedrop the brightest key color white
set its matching softness 0%
add a matte choker effect


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]