Page 118 - DCAP303_MULTIMEDIA_SYSTEMS

Multimedia Systems

notes • Fingerprint scanner
• Barcode reader
• 3D scanner
• Medical imaging sensor technology
 Computed tomography
 Magnetic resonance imaging
 Positron emission tomography

 Medical ultrasonography
audio input Devices

The devices used for capturing audio are:
• Microphone
• Speech recognition
Note that, MIDI allows musical instruments to be used as input devices as well.

Touchscreens
Touchscreens are monitors that usually have a textured coating across the glass face. This coating
is sensitive to pressure and registers the location of the user’s finger when it touches the screen.
The Touch Mate System, which has no coating, actually measures the pitch, roll and yaw rotation
of the monitor when pressed by a finger, and determines how much force was exerted and the
location where the force was applied.

Other touchscreens use invisible beams of infrared light that crisscross the front of the monitor
to calculate where a finger was pressed. Pressing twice on the screen in quick and dragging the
finger, without lifting it, to another location simulates a mouse click-and-drag. A keyboard is
sometimes simulated using an onscreen representation so users can input names, numbers, and
other text by pressing “keys”. Touchscreen recommended for day-to-day computer work, but
are excellent for multimedia applications in a kiosk, at a trade show, or in a museum delivery
system anything involving public input and simple tasks. When your project is designed to use
a touchscreen, the monitor is the only input device required, so you can secure all other system
hardware behind locked doors to prevent theft or tampering.

6.5 output Devices

Presentation of the audio and visual components of the multimedia project requires hardware that
may or may not be included with the computer itself-speakers, amplifiers, monitors, motion video
devices and capable storage systems. The better the equipment, of course, better the presentation.
There is no greater test of the benefits of good output hardware than to feed the audio output of
your computer into an external amplifier system: suddenly the bass sounds become deeper and
richer, and even music sampled at low quality may seem to be acceptable.

6.5.1 audio Devices
All Macintoshes are equipped with an internal speaker and a dedicated sound clip, and they
are capable of audio output without additional hardware and/or software. To take advantage
of built-in stereo sound, external speakers are required. Digitizing sound on the Macintosh
requires an external microphone and sound editing/recording software such as SoundEdit16
from Macromedia, Alchemy from Passport, or SoundDesigner from DigiDesign.

112 LoveLy professionaL University