1. Using Video The science of video Why do we perceive it? The psychology of video Where do we use it? The technology of video How can you capture and edit it? QuickTime VR process

2. The science of video Exploited human visual limitation: We cannot perceive easily visual difference when they change faster than 10 Hz

3. The psychology of video A powerful medium, conveying: Motion Changing facial expressions Associated audio Significant emotional impact Tend to relate video with reality Disadvantage: Slow for users with dialup connections (but improves quickly) Best for users with broadband connections Which is approaching half of U.S. households that have Internet connection Includes most company intranets

4. The technology of video If it is recorded as raw video, i.e., a full image per frame, it can be huge. Rate = frames/sec (aka: fps) Raw size = frame size * length of video For 10 sec raw 30 fps video of size 640 x 480 true color video (640 * 480 pixels) * (24 bits/pixel) * (30 frames/sec) * 10 sec / 8 bits/byte = ________ Compression algorithms record only differences between frames Quicktime.mov Mpeg Avi

5. 5 Tips for recording video Choose camera carefully. Steady the camera, use a tripod. Avoid shooting into light and backlit scenes. Limit pans and zooms. Frame the subject. Make inventory of required shots. Use highest resolution available. Add external microphones. Use headphones to monitor sound quality. Record background sound for use in editing. Don’t break the time code.

6. Medium shot

7. Close up shot

8. Extreme close-up – the best

9. Video formats for the Web NameFile extension OriginatorAdditiona l codec? Streaming?Additiona l player? Audio-Video Interlaced.aviMicrosoftYesNo QuickTime.mov.qtAppleYesConfigurableNo MPEG Video (MPEG-4).mpgMotion Picture Expert Group No Real Video.ram.rmRealNetworksNoYes – requires server software Yes Chapter 11: Multimedia Copyright © 2004 by Prentice Hall