Assignment #1: Introduction to Chroma-keying

Due: 2/07/2006 2PM!

Goals | Part 1 | Part 2 | Part 3 | Submission Info

New for this 2006: (a) 2 videos required (b) A write-up required

Goals:

1. Undertake the entire pipeline from shooting video to digitizing video to maniplulating & processing video to rendering new video to encoding and saving a file for submission.
2. Learn the basics of Adobe Premiere and After Effects so you can use both for simple editing and so you know how to apply the built-in features, should you need them.
   OR learn the basics of Final Cut Pro / Shake for Mac Users!.
3. Spot the challenging aspects of compositing: segmentation, reflections, shadows, lighting, and real/virtual camera alignment.
4. Determine how to control the environment that best supports chroma-keying.

NOTE: This is a learning exercise, so it only affects your grade if you don't do it. Make the footage look as good as possible, but it won't be pretty for reasons we'll talk about in class.

NOTE For Mac Users: You can do this assignment using Final Cut Pro and Shake.

Part 1: DV capture

Bring a photo-copied version of your ID and a printed version of the sign-out form to checkout a camera and a tripod from the TA. Since we are using 10 cameras for over 30 participants, you better schedule your check-out early. Contact TA right after the class or by email (jerry@cc).

Film a subject in front of a solid-color background. It doesn't have to be fancy, just something that moves around for about 15sec. One good area to film in the chroma-key area is in the TSRB 325 or in any space that you can convert into a controlled space with fixed color background and controlled lighting. In TSRB 325 we have a green background and floor with plenty of lightings you can control. Please use them carefully. (Information on the access to TSRB 325 will be announced to you by email.)

The Lab(TSRB 325) Access Info:  The Green Screen Lab is in TSRB 325. You need a GT Buzz Card to access the building. If it is duiring regular business hours (10a-6p), you can enter the buidling, go to the third floor looking for IMTC and if you ask nicely, someone can let you in to the lab. Or you can look for Jerry on the second floor (TSRB230), too. For after hours/weekend access, you will need to upgrade your BUZZcard to a PROX BUZZcard (all that means is that it has a PROXIMITY sensor). I believe you can do this at a BUZZcard place for $15 (sorry!). If you have that, send a note to Scott Robertson (scott.robertson@imtc.gatech.edu) with "Access to Green Screen Space for 30 Undergrads for DVFX" in the subject line and give your name, GTID, and the 7-digit number on the back of your PROX Buzz card. He will get you the access. Deadline for getting this info to Scott is Monday 11am. NOW for something VERY IMPORTANT: There is a lot of expensive equipment in that space, be careful. Turn-off the lights and also DO NOT walk on the green screen with shoes.

Consider turning _off_ various auto-options of the camera (things like auto-focus and auto-gain will cause your solid color to change its appearance throughout the sequence). The footage is now a DV file sitting on the miniDV tape, and needs to be pulled onto a hard-disk as described in class.

Part 2: Premiere (These are for PC folks, MAC folks, feel free to use MAC OSX software as needed)

Composite the movie onto an image or movie of your choosing. If you are eager to learn this stage before getting access to a camera, some sample sequences are in

/net/dvfx/DVFX/2006/sampleData/*.avi.

Rather than ftp, we recommend you set up a symbolic link from your UNIX home, so you can put/get files through samba:

unix% ln -s /net/dvfx/DVFX/2006 DVFX (In Unix)

Guiding Steps

1. Run Premiere
2. Agree to the default project
3. File->Import->file your favorite of the movies on DVFX
4. Drag its icon from the project to the timeline's Video2 layer
5. Import an image or movie you found/generated/stole
6. Drag it to the Video1 layer.
7. In the time-line, play with the time-slider, moving files around in time, etc.
8. Right-click the green-screen footage and pick Video->transparency.
9. Try the different keying types. Especially play with the sliders for Chroma keying and Difference Matting (notice, this asks you for a matte-file, which you can extract from the sample movie by rendering out a frame).
10. Play with the Sample window and its controls (try holding down space-bar and Alt). Notice the 4 handles in the corners of the sample window.
11. When done, adjust the blue Workspace bar at the top of the Timeline window to select the part you want to render.
12. With the Timeline window active (won't work otherwise), File->Export->Movie.
13. Check all your settings! You want to export an .avi, and you want the codec to be none/DVRaptor/other at high quality. To stay under 200MB in final size, try rendering a shorter movie, or using a different output resolution.
    Extra: Add a title screen and a transition effect, and maybe some audio.

Part 3: After Effects (These are for PC folks, MAC folks, feel free to use MAC OSX software as needed)

1. Same as above, but very slightly different interface, and lots of other features to play with.
2. Run After Effects
3. Effect->Keying->Color Key, and play from there Also try Transfer Mode->Difference and others
4. It's not blue, but it's still just above the time-line.
5. Composition->Add to Render Queue.
6. Window->Render Queue, and adjust the settings to suit.
   Extra: make a split screen using masks and/or Transformation of the layer
    

Submitting results:

Videos:

Report (Write-up):

In addition to the above submitted video, create a webpage on your class swiki pages (see template) showing at least 1 image from both of your video, marked in some drawing program and a description of was the problem in the marked region and how it could be solved.
 

This assignment should not take long, even if you have never used these tools before. You're getting so much time to complete it because you're working individually, so not everyone can check out a camera at the same time... i.e. don't wait until the last minute.

Grading Breakdown:

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Last updated: March 08, 2006 01:41:21 PM.