need help finding a place to track on my footage

i've been trying to track this footage for sometime now. every time i get a track and apply it to my layers it finds a way to shift and move. not very much, but enough for me to notice.

here is the footage.

i'm trying to find a place to track to add text.

should i use the piping on the wall, the bricks?

any advice is greatly appreciated

The Pipe would work well cause of the contrast, as well the ' between the two letters.

Wait for Hype to see this, he can help you out best I think, You are using AE right?

maybe track the letters "Coca Cola" on the wall. I'm assuming there's no huge, drastic camera move happening here. You said you're getting a little bit of drift?

I would track at least 2 spots on this thing, probably more like 4, and average them together. The pipe would work, like Mike said, and you could also track the Coca Cola letters. If the track drifts on them, in the tracking options try changing it from "Luminance" to "RGB", cuz the red channel on this image is probably nice and contrasty. If it still drifts, leave it on whichever worked better (luminance or RGB), and click the little box that says "adapt feature on every frame".

Also, if there's rotation in this, you're going to want to be careful where you track both the position and the rotation. For example, if you're going to use compositing to replace the image of the pipe, or maybe put a picture of something like a bottle sitting on the pipe, you'll obviously want to track the position at the pipe, and the rotation and scale elsewhere, like the Coca Cola letters. But, if you're trying to replace the Coca Cola letters on the wall with your own advertisement, then track the position of the letters, and use the pipe for tracking rotation and scale.

another thing you could do is pre-comp this footage, and in the pre-comp, add a levels adjustment and really turn up the contrast. like, REALLY, REALLY high! then go back into the other comp and it should track fine. when you're done and you have your track, just go delete the levels adjustment.

if I was replacing the Coca Cole letters with my own letters, I would track four points on the word Coca Cola. Imagine you drew a box around the words Coca Cola. I would track the letters as close to the four corners of that imaginary box as I could. then I would average all four of them together using this script:

http://www.aenhancers.com/viewtopic.php?t=136

I would apply that averaged track data to a null layer or a solid with the invisibility turned off. then I would track the center of the letters, and have the scale and rotation tracking the pipe in the corner. I would apply that data to a second solid.
then i would copy/paste the rotation and scale keyframes from the second solid onto the solid with the averaged position data.
then i would parent my new advertisement layer to that solid.

holy crap, can I babble or what?! sorry that's so long, just trying to be thorough... hope that helps! if not, post the footage and I'll track it while video capturing my screen, then i'll post the video.

hey man, this should be no problem, all I've done here is desaturate the footage, invert it, do a levels adjustment, and put a small blur on it. Do this to your footage, then track it, then take the effects off of it. I think you'll find that it tracks better when it's tracking the luminance rather than the rgb channels. Also, trackers work better while tracking dark on light rather than light on dark. I have circled a couple places where I would start to track, if they don't leave screen you should be allright, but if they do, you can offset the search region and still get away with quite a bit.

Give it a try and let us know what happens.

-Z

nice one zach! yeah, do what zach says!

well, to be honest the coca-cola text is something i've added to the footage. it originally had PEPSI text. my goal with this video is to remove and add an object to the footage, making it as realistic as possible. granted it's not a cg object. baby steps.

i'll try to post the footage. just have to find a place to host it. it's hand held footage.

i'll get your opinions on it and see if i should adjusted or if i'm just seeing things. if you all agree it drifts i'll try both of your techniques. i have the averaging script, etc. etc.

almost forgot, i'm using AE 7

brb.

Here is my original tracked footage. i think it drifts a bit.

http://media.putfile.com/Coke-Wall

Here is the side by side comparison of the original footage and my original tracked footage.

http://media.putfile.com/coke-wall-comparison

Are you guys talking about tracking in After Effects?

yeah man, it drifts a little. What you are going to want to do is mix the techniques I mentioned earlier, and even try those and track it backwards instead of forwards, sometimes that helps too. But if you are going to do a replacement like that one, I'd definately do the four point track and cornerpin your footage.

Iest: You bet man. The glorious art of tracking in AE.

hope this helps you man.

-Z

i tracked it and recorded my efforts. will post it as soon as its done compressing.

ok, here's my little effort at tracking the footage you posted.
I just did a four track average. In the video tutorials section I have a corner pinning tutorial called "Screen Replacement", if you want to go that route and have never tried corner pinning.

i use that script i mentioned earlier. i think it's 15 minutes long.

http://www.mackdadd.com/tutorials/coke_ ... xample.mov (1.05 Mb)

http://www.mackdadd.com/tutorials/coke_ ... torial.mov (156 Mb)

hype: when you were choosing an area to track the footage did you use the edges of letters? or did you find a black spot and just put the track in the middle of the spot?

i've seen other tutorials on tracking in AE and they always place the track a corner or edge of an object. i wasn't sure.

yay i knw how to track in AE now... thx dude, i'll see if i can come up with somthing.... oh, do you need to do somthing more when you rotate the camera around for the tracking to work?

thx a lot dude

hype: after watching the tutorial you posted i finally understand the tracker. i was focusing the tracker position on specific pixels, not shapes. that makes a lot more sense. also, thanks a lot for actually making a tutorial just for my question.

i'll try tracking the footage tomorrow using the technique you showed and post it on here.

thanks man.

bzudo - no problem, dude! super easy, and i figure since i paid for my little screen capture utility, i might as well use it once in a while...

richard, i don't know what you mean about sotating the camera, exactly. if you mean you bring in footage, rotate it in AE, and then try to track it, it will use the unrotated original footage for the track. to track on your roatated footage, simply pre-comp your rotated footage and be sure to select "move all attrubutes into new composition" in the dialogue window that opens. then, in your original composition, you can track on the rotated footage.

bzudo - do you mind if I post this in the video tutorials section here at SimplyCG? I'm asking cuz it's your footage I used to do it. But it seems like maybe it would help alot of people to see how basic tracking works in AE.

Nice one man, thanks a lot for making the tutorial - it looks super easy to track within AE - I have deeply under-estimated AE, I think im gonna get to know this software a little bit better.

Another thing I was wondering was - say if you track your scene in AE - is there anyway to export the tracking data to Maya or Max? That would just be the piece de resistance!

Ha ha - It's great you've got a folder with everyone's picture in it man!! good going!

well here is my try at following the tutorial hype posted. i think it tracks a lot better. let me know what you think. how does it look?

http://media.putfile.com/coke-wall-retry-2

Great Job, looks very realistic!

yep, much better! nice work!