Transcript Advanced I/O Devices

CIT 1100
In this chapter, you will learn how
to:
◦ Explain visual capture devices
◦ Describe audio devices, both
input and output
◦ Explore game controllers
◦ Explain television tuners
Scanners
 Used to make digital copies of existing
photos, documents, drawings, and more.
 Better scanners have the option of copying
directly from a photographic negative or
slide
 In this section, you'll look at how scanners
work and what you need to know to select
the correct scanner
All flatbed scanners work the same way, a photo or
object placed face down on the glass, close the lid,
then software initiates the scan.
The scanner runs a bright light along the length of
the glass tray once or more to capture the image
 A moving scanning arm contains sensors. Glass,
mirrors, and electronics, work to convert the light
into signals sent to the computer
 Nearly every manufacturer has some sort of drivers
and other software to create an interface between
your computer and the scanner
Image-editing software can be used to capture
the scanners output allowing modifications to
the original object
 The most commonly used software for
capturing output into an application is TWAIN
 TWAIN stands for Technology Without an
Interesting Name
Most scanners offer a feature called optical
character recognition (OCR), a way to scan a
document and have the computer turn the picture
into text that you can manipulate by using a word
processing program
The contents of the textbook was scanned using
OCR, which was used to create the Power Point
presentation used in this class
Even inexpensive scanners will scan at high
resolution
All modern scanners can do 48-bit scans for
capturing enormous amounts of color information
The 48-bit number represents three16-bit
sensors, one for each color: red, green, and
blue (RGB)
The number of bits reflects how many variations
of color can be captured, 16-bits allows 65536
variations of color from a single spot
Judging one scanner from another, boils down
to three factors:
 Quality of the optics, sensors, and electronics
 Capability of scanning transparent objects
 Auto-feeding capability
Digital cameras and camcorders electronically
simulate older film technology
 Camcorders record moving pictures
 Modern digital cameras and camcorders
aren’t just still/motion devices they can do
both
 You can record a movie on a small camera,
for example, or still images on a camcorder
Consumer grade digital cameras replace film
with removable storage – Flash Memory Cards
Some camcorders use high-speed tape or
tiny hard drives called Micro-drives
Nearly all digital cameras have the capability
to plug directly into a Hi-Speed USB port
The newest method incorporate HDMI
Consider the amount of information a particular camera
can capture when comparing features, expressed as
megapixels
 Instead of light-sensitive film, digital cameras have
one or more CCD (charge-coupled device) sensors
covered with photosensitive pixels (photosites) to
capture the image
 The more pixels the higher the resolution of the
images
 A two-megapixel camera produces snapshot-sized
4x6” picture with print photo quality, a five megapixel
unit can produce photo quality 8x10 inch print
Camcorders capture video in one of two formats,
High Definition (HD) or Standard Definition (SD)
 HD captures will be widescreen to match HD TV
 SD captures stay within the 4:3 aspect ratio to
match older style televisions and monitors
 HD captures higher-resolution images for the
most part, though a high-end SD camera will
outperform a lower-end HD camera any day
PC cameras, Webcams are fairly new type of advanced
I/0 device
 Features to look for when buying webcams and some
problems you can run into using them:
◦ Image quality - measured in pixels. There are webcams with
resolutions of as few as 100,000 pixels, all the way to
webcams with millions of pixels which would require a huge
amount of internet bandwidth
◦ Frame rate - number of times the camera scans per second,
higher frame rates make for smoother video using more
bandwidth, 30 frames per second is considered the best.

A good camera with a high resolution and fast frame
rate will provide excellent video conferencing capabilities
Sound controllers enable the computer to play
and record sound. All modern computers come
with sound controllers built into the
motherboard
The simplest sound controllers have three 3.5
mm audio ports, called jacks
Most sound controllers have color-coded jacks for the
specific connections:
Connector
Color
Purpose
Line out
Green
Main speakers or headphones
Microphone
Pink
Recording sounds
Line in
Blue
Sound input from an audio device
Subwoofer
Orange
Thumping bass with a subwoofer attached
Rear surround sound
Black
Rear speakers
Middle surround sound
Gray
Extra speakers in a 7.1 sound setup
Video games come with a host of controllers for
controlling aspects of the game. You can get a
joystick for controlling flight simulation games
Force feedback game controllers are output
devices as well as input devices, when the stick
is shaking on a hard turn and resisting your
efforts
Most local TV stations broadcast high definition
signals, with the proper TV tuner, you can watch
HDTV on a PC
 By incorporating a cable or satellite feed you can
watch television as you would with a regular TV
 To install HDTV requires four components:
1.
2.
3.
4.
Tuner device
Antenna or cable connection
Tuning application
Program guide

Tuners come in just about every expansion
option available for computers:
◦
◦
◦
◦
PCI
PCie
PC Card or Express Card
Hi-Speed USB for desktop and laptop computers
Tuner hardware comes with a
standard coaxial connection
Once installed you need to load the specific
application or applications
 If you have Windows Media Center (through
either that version of Windows XP, Windows
Vista Ultimate, or Windows 7), that will often
be the tool of choice
 Ubuntu MYTH TV provides a complete open
source Home Media application