A Media Computation Cookbook

1. A Media Computation Cookbook Manipulating Images and Sounds for Use in Alice Part 1: Image Manipulations Part 2: Advanced Image Manipulations, e.g., changing colors in an area Part 3: Chromakey for digital video effects Part 4: Manipulated Alice images Part 5: Sound manipulations Part 6: Manipulated sounds in Alice

2. How to use image manipulation with Alice • A. Create an image to appear as a Billboard in an Alice world. • B. Create images in Alice that you can manipulate as snapshots. • Like with chromakey • C. Make movies in Alice that you can then manipulate as video.

3. A. Loading images as billboards in Alice • Step 1: Make a cool image that you want to appear as an object in your Alice world. • Step 2: Import the image as a Billboard.

4. Step 3: Move it around and use it like an object

5. B. Manipulating an Alice world snapshot • Step 1: Set up an Alice world the way you want it. • If you want to chromakey, • drag the “Ground” into the trash • make the “Atmosphere Color” of the world blue (default) or green.

6. Creating the snapshot • Step 2: Program your objects to move where you want them to go. • Step 3: Play your world, and at the right time, hit “Pause” and “Take Picture”

7. >>> capturedbirds = makePicture( getMediaPath("capture00.jpeg")) >>> capturedbirds Picture, filename W:\mediasources\capture00.jpeg height 360 width 666 >>> birds = scale(capturedbirds, 0.75) >>> birds Picture, filename None height 271 width 500 >>> chromakeyBlue(birds,moon) Snapshot from Tutorial,Moved to the Moon

8. C. Manipulating an Alice video • Step 1. Tell Alice not to remove frames after making a video! (Change Preferences.)Only have to dothis once.

9. Record your video • Step 2: From File menu, choose “Export Video.” • Click “Record” then “Play” • When done, “Stop Recording” and “Export Video.”

10. Your frames are now saved

11. Doing Chromakey to a Set of Frames import os def chromakeySet(frames,background): newdir = "C:/temp/" for file in os.listdir(frames): if file.endswith(".jpg"): printNow(file) frame = makePicture(frames+file) chromakeyBlue(frame,background) writePictureTo(frame,newdir+file)

12. Using Chromakey to put Penguin in the jungle >>> jungle = makePicture( getMediaPath("jungle.jpg")) >>> chromakeySet( "W:/mediasources/frames/", jungle)

13. Try it! • Take a snapshot of an Alice world and put it on a new background. • Put yourself into an Alice world. • Put an Alice character into our world. • Create a collage with various pieces of the pictures we have.