Here is my problem: I have shot a documentary in which I used a car and on that car I've put some stickers from the sponsors. Now, one of the sponsors won't pay and I feel like removing his sticker from the car in the post, but I don't know how to do it. The sticker is not very big (depending on the shot: it can be very big on the screen, but it's not very big on the car itself).

Is there a software that can track a moving object across the screen and either blur that part of the picture or stick something else over it?

Notice that I have no problems removing the sticker in the static (i.e. tripod) shots, only when the car is moving, or when the camera is handheld. Doing it frame by frame would be a nightmare...

Help on this issue would be very much appreciated indeed!!

Senad

Well I know you can do it pretty easily in Avid. What software are you using? You just need some motion tracking software.

You could do this in After Effects. I would track the sticker area, there are lots of ways to do this depending on how the shot is composed. Could you upload a 30sec clip to Vimeo in final quality and I will download it.

James

Thanks for the replies

I use Premiere for editing. I can't use After Effects but my friend who did the grafics work can. However he doesn't seem to be aware of a tracking option in AE (he's using CS2). Where can we look for tracking options in AE?

I have no Vimeo account but you can take a look at the trailer on you tube

http://www.youtube.com/watch?v=qwkuW_ciqeU

There are about 4 shots of the car in the trailer but they are very short so this is just for info.

Thanks again, this is a burning issue!!!

Have your AE friend watch this: VIDEO COPILOT | After Effects Tutorials, Plug-ins and Stock Footage for Post Production Professionals (http://www.videocopilot.net/tutorials/basic_sky_replacement/)

It tracks a sky but you can apply the principal to anything and track it really.

And Vimeo has a free account - 500MB a week upload limit.

Thanks Shaughan, I will forward the link to my partner. Hope we get out of this somehow...

Senad...

What you're asking seems pretty straightforward and is a classic example that's often used in tutorials.

AE, the broadcast version, has a tracker that can help you do the trick. The most recent version of AE comes with Mocha, a very powerful planar tracker that can even deal with perspective distortions.

Imagineer Systems - Products (http://www.imagineersystems.com/products/mocha/)

Dean, thank you for your reply.

I imagine that the issue is familiar to people who do the FX, compositing or other digital tricks but I'm just a simple cameraman good only to open/close the iris and pull the focus... ;-)

In any case, I'm glad I have posted my question at the right place and I hope that, with the guidance I have received, I'll be able to fix this issue.

Thanks to all for your help.

Senad

The only potential problem I see with the shot is that there is a lot of distortion due to wide angle lens. Just not sure if AE can deal with the fact that the rectangular sign sometimes looks like a football shape - I'm pretty sure that Mocha could do it.

Imagineer used to have a special price for their stuff for freelancers - I think it was about 10% of list price. Not sure they still do this but worth checking.

Before you spend any money on Mocha, check to see if you have the latest version of AE.

If you do, then it has the Mocha plug-in. If not, you might consider upgrading to get Mocha that comes with the upgrade.

Good point Dean! It's included with the CS4 version of AE.

We do have the CS4 now. However, we haven't started working on this issue yet, but I guess it will be pretty soon.

Thanks everyone for your comments!

Senad

I've been rummaging through some of my training materials on Mocha AE and am getting more concerned that it won't do what you want unless you un-distort the footage first. I think you'll need some kind of workflow like 1) remove lens distortion, 2) track an undistorted rectangle (Mocha should be good for this) 3) Replace the rectangle with a new one, and 4) Re-distort the footage back to the way it was.

I'm pretty sure something like this kind of workflow will be necessary but am not likely to be much help on the details of how to do it with any particular software package.

You can manually compensate for changes in aspect and distortion in Mocha.

Also, AE CS5 now has a roto-brush tool that is absolutely incredible. It might be a faster way of handling this problem.

PFTrack also has undistort ability. Have to go through the Mocha stuff again and get smarter.