Transcript MULTIMEDIA TUTORIAL-II SHASHI BHUSHAN SOCIS, IGNOU Hardware and Software Capturing & displaying image Graphics Adaptors Scanners Digital Cameras Photo CD Monitors Hardware and Software for Capturing & Displaying Image Refresh Rate Resolution Magnetic Fields Graphics.

MULTIMEDIA TUTORIAL-II
SHASHI BHUSHAN
SOCIS, IGNOU
Hardware and Software Capturing
& displaying image
Graphics Adaptors
Scanners
Digital Cameras
Photo CD
Monitors
Hardware and Software for
Capturing & Displaying Image
Refresh Rate
Resolution
Magnetic Fields
Graphics Adaptors
Also called video cards are limiting
factors in display
Two standard


VGA
Super VGA (S-VGA)
Graphics Adapters
VGA Standard provides 16 colours at
640 x 480 or 256 columns at 320 x 200.
VGA standard is insufficient for multimedia application
SVGA is generally used for multimedia
application

(640 x 480 in the 64 k colours)
Graphics Adapters
SVGA is not a standard and different
drivers are needed for each card.
Colour depth of a card depends upon
the amount of memory
Graphics Adapters
Graphics cards are usually supported
with 1024 x 764 with 16 million colours
and 2 M memory.
Many cards claim to be graphics
accelerators having an extra IC which
does the calculation necessary to
determine what parts of video memory
need updating.
Digital Cameras
Digital camera, also known as still video
cameras, take still photographs and put
them directly into digital media without
using film. The images are usually
saved to a floppy or hard disk and can
then be downloaded into your
computer.
Refresh Rate
Minimum refresh rate of a monitor
should be 60 Hz (I.e. the screen is
redrawn 60 times a second)
Preferable 70-75 Hz in order to prevent
any flicker
Computer Colour Models
RGB (Red, green blue)
HSB (Hue, Saturation, Brightness)
HSL (hue, Saturation, lightness)
CMYK
CIE
RGB
In RGB, colour is specified by setting
the amount of red, green and blue in
the range of 0 to 65535.
HSB and HSL
In the HSB and HSL models, you specify
hue or colour as an angle from 0 to 360
degree on a colour wheel and
saturation, brightness and lightness as
percentage
HSB and HSL
A lightness of 100%
colour
A lightness of 0% A lightness of 50% -
-
White
Black colour
Pure colour
HSB and HSL
Saturation is the intensity of the colour.
At 100% saturation, the colour is pure;
at 0 percent saturation, the colour is
white, black or gray.
Location of Colour in colour
wheel
Colour
Red
Yellow
Green
Cyan
Blue
Magnets
Degree
0
60º
120º
180º
240º
300º
Video
Of all the multimedia elements, video
places the higher performance demands
on your computer and its memory.
Video : Storage Requirement
Requirement of a still colour image
- 1 M Byte (Assumption)
For Appearance of motion multiply by 30 (30
times/sec.) – 30 x1 M Byte (to play video per
second)
To play video per minute – 60x30 MB = 1.8
GB
To play video per hour –1.8 GB x60
=108GB/h
Broadcast video standards :
Analog
Three analog broadcast and video
standards and recording formats are in
use around the world.
NTSC
PAL
SECAM
HDTV
Broadcast Video Standards
Each system is based on a different
standard that defines the manner in
which information is encoded to
produce the electronic signal that
ultimately creates a television picture.
National Television Standard
Committee (NTSC)
Used in Japan, USA for broadcasting
and displaying video.
Defines methods for encoding
information into the electronic signal
NTSC
As specified by the NTSC standard, a
single frame of video is made up of 525
horizontal scan lines drawn into the
inside face of a phosphors coated
picture tube of every 1/30 of a second
by a fast moving electron beam.
NTSC
The picture is laid down on the screen
in two passes, first odd numbered lines
and then even of 60 passes/second or
60 Hz. Using two passes like this is
known as interlacing and helps prevent
flicker. Remember that computer
monitors draws the lines of an entire
frame in one scan, without interlacing.
PAL (Phase Alternate Line)
Used in UK, Europe, Australia and South
Africa.
Uses 625 lines in the frame rate of 25
frames/s
Like NTSC it is interlaced at 50 Hz.
SECAM (Sequential Colour and
Memory)
Used in France, Russia and other
countries
Uses 625 lines and 50 Hz. System
Differs from NTSC and PAL in basic
technology and broadcast method
HDTV (High Definition TV)
Going to be the Next Standard
Provides 1200 lines
3, different standards available, two of
which are analog and the third digital.
Digital Video
Variety of digital video formats
Video files are very large, all formats
include some kind of compression.
Formats such as AVI – Microsoft's video
for windows and Apples Quick time use
several different kinds of compression.
Video Colour
Colour reproduction and display is
different between television and
computer monitors.
Computer use RGB component video
(they split colours into red, green and
blue signals) Their colours are purer
and more accurate then those seen on
a television monitor.
Video Colour
NTSC television uses a limited colour
palette and restricted luminance
(brightness) levels and black levels (the
richness of the blocks). Some colour
generated by a computer that display
fine on RGB monitor may be illegal for
display on an NTSC television.
Video Recording Formats
Several video recording formats existing
Formats represent different means of
putting the video signal onto tape.
Video Recording Formats
S-VHS
Hi-8 (High Band 8 mm)
Betacam
S-VHS and Hi-8
S-VHS video keeps the colour and
luminance information on two separate
tracks, which gives better quality.
Hi-8 is better quality than S-VHS and
one can make unlimited VHS copies
without the degradation when copying
from VHS to VHS.
Principles of Animation
Animation is possible because of a
biological phenomenon known as
persistence of vision. An object seen by
the human eye remains mapped on the
eye’s retina for a brief time after
viewing.
Principles of Animation
If the location and shape of an object is
changed rapidly, the eye will perceive
change
Animation
Television video builds 30 entire frames
a picture every second; the speed with
which each frame is replaced by the
next one, makes the images appear to
blend smoothly into movement.
Movies are shot at 24 frames per
second.
Animation
To make an object travel across the screen
while it changes its shape, just change the
shape and also move it a few pixels for
each frame. Then, you play the frames
back at a faster speed, the changes blend
together and you have motion and
animation.
COMPUTER ANIMATION
One can usually set your own frames
rates on the computer, but the rate at
which changes are computed and
screens are refreshed which will depend
on the speed and power of Hardware.
Animation File Formats
Director (MMM)
Animator P & D (FLI & FLC)
Super Card, Director, Super DBD (PICS)
Window Audio Video Interfered format
(AVI)
Macintosh Time-Based Data Format
(Quick Time)
Making Animation that work
Multimedia Authoring Systems typically
provide tools to simplify creating
animation within that authoring system.
And they often have a mechanism for
playing the special animation files
created by dedicated Software.