[Joe Moya]

This may not be a matting issue at all…

… can’t you just narrow the lighting? That may create the effect you want… if not…

…then it is still a alpha matting issue…

…Add an alpha matte layer (perhaps inverted?) to the layer between the light layer and the scanned photo. That’s it… the lighted area will only come through where the matte is transparent with the watch in the layer below the matte (i.e., background).

You can feather the alpha matte layer for the image if you want to make the lighting appear as a smooth transition… this is called an edge matte. You can duplicate the (inverted?) matte footage, apply a Channel>Shift Channels to this track footage and apply a Alpha>Full On Red>Alpha Green>Alpha Blue>Alpha… Then, apply a Stylize>Find Edges effect and (invert it – maybe?). Then, blur the edges a bit and use Color Corrections>Curves, Color Correction>Levels or Channels>Mini-max to +/- the range of the matte.

Joe

[Joe Moya]

I am not sure why you would want to draw a mask/matte in this fashion…the cube is already a mask/matte. You simply need to invert the alpha channel and the “square/cube” becomes transparent… to replace the cube back into the video… you simply need to add a layer behind the now transparent “square/cube”.

A convalute way to change the background and still keep the “square/cube” in the video would be to take the original alpha matte with a transparent background… add what ever background you want… save as an AVI file… then, import this new matte (i.e., new background with transparent area where the “square/cube” use to be)… then, add back the “square/matte” by placing a new layer with the “square/cube” under the saved AVI file(w/alpha) to put the missing object back into the video.

If you got rid of the background in the video… then you have your matte… there is no rotoscoping needed. Rotoscoping (or keylighting using Luma or what ever) is process used to remove backgrounds from a chosen forground element. In your example, you already got rid of the background with the luma key.

Invert the matte…. that is the solution.

Joe

[Joe Moya]

Yes… this is what I referred to as inverting the alpha channel…

Normal alpha channels make the background transparent… inverting the alpha channel does the opposite… it makes the background visible and makes the foreground invisible.

I typically do this with editiing software since it much easier… in AE, you can do this a couple of ways… you can switch the layers between what is forground vs. background relative to the matte…and/or… use inverted version of luma matte or alpha matte with or without invert effect (Effect>Channel>Invert).. each method produces different matte inversion matte effects.

Basically, if you have a rotoscoped or keylighted seperated elements of you videio… then you can make either elements transparent. But first, you need to rotoscope each frame (or use Mocha) if you want to create tight mattes.

There are ways to make rotoscoping process a tad bit more easier, but I have never used AE for this purpose because even with this process the rotoscoping is still very time consuming. If memory is correct… this rotoscoping “help” is done by using Paint and changing the duration for the paint stroke (or erase) that will interpolate between frames by changing custom setting (in the paint pallette) to 2 f (frames). If you do a search you will probably find better instructions for this process.

Good looking manually producing rotoscoped frames is difficult to get… most instances, you will get a “lava lamp” effect for the edges because you can not get the edges to match from frame to frame… this is why having AE interpolate between frames helps (specially, if you use more than 2 frames… the trade off is this… more frame interpoliation produces smoother edges for the matte but less accurate… less frame interpolaltions produces greater edge accuracy but less smooth edges (i.e., lave lamp edges).

If you are doing trees/people moving, you will find that rotoscoping is EXTREMELY difficult… specially, if you have motion or moving legs involved or Hair. You might notice that most tutorials use objects as samples and not people… why?… because they are much easier to rotoscope than organic shapes that are moving (i.e., such as people/persons).

Hope this helps.

Joe

[Joe Moya]

Hmmm… OK… it sounds like what your asking for is called the alpha channel of the video that has been rotoscoped or keylighted with a green/screen. But… some how I don’t think I am answering your question.

What I want is for it to automatically create a mask around anything that isn’t transparent for every frame of the clip. Is this possible?

An alpha channel does this… and you can invert the channel to make either the background transparent or the foreground.

An alpha channel can be created (or automatically created) with any rotoscoped video. The alpha channel is the matte.

Are you asking… Can you create multiple mattes of a video with more than one object within a video at one time?

… Not that I know of… but, you can make many layers for each object within the video to create multiple mattes for each object within the same video.

[Joe Moya]

Well… yes rotoscoping can be avoided… but that requires a blue/green screen background…

If your video doesn’t have a distinquishable background to seperate (as in a blue/green screen) then the answer is no… or at least that I know of using AE. On the other hand, Mocha by Imagineer can do this easily if you can afford the software.

Joe

[Joe Moya]

I could be wrong… or , don’t quite understand… but, I think the reason your picture “squashes” up is because it is a 2D picture… no other reason.

When you rotate 2D pictures you see it for what it is… a 2D picture… there is no depth.

[Joe Moya]

Right click on any one of the Keyframes and choose Keyframe Interperlation (or something like that… don’t have AE open… but, I think it is the fourth choice from the top)…a window will open up and you can change it to linear.

[Joe Moya]

I have had this happen frequently with my Optura40… and, it took me forever to find out why this would happen off and on (well, sort of…).

Most of the time, my problem was caused the connection to the camera and/or firewire connection on the computer.

Are you using the same connection cable? You need to be specially aware of the connection end that attaches to the camera…. you need to push it in all the way… with mine, I have to push it REALLY hard. Which BTW, really doesn’t make sense since I also see it as hardware that is being recognized but with the “?” mark in the device manager.

Now that I noted a common solution to my problem… I have to admited that there have been instances where I had to simply rebooted the computer to get the digital camera to work (make sure the camera is turned on and connection is good).

Another solution which I have tried (…which is one among many… so many of which I can’t remeber some of the attempts… but one thing that seemed to work frequently is that I used MS’s Movie Maker because in some instances no other software I had worked (and, I have a lot of software to choose from). You might try and us MS’s Movie Maker.

I am not sure what this problem is exactly… but, it seems to only happen with my Canon… personally, I think it IS a driver issue… but, I can’t prove it.

Hope this helps… Joe Moya

[Joe Moya]

Nope… just went back to the site again… and it has the problem it had earlier… waaaay slow moving from page to page.

There is something wrong with the site…

[Joe Moya]

hmmm… interesting… I went back to the site and it seems to be working normal now…

… must have been something wrong at the time I had accessed the site….