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

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.

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.

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

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.

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”

Snapshot from Tutorial, Moved to the Moon >>> 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)

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

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

Your frames are now saved

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)

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

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.