Multimedia Systemsce.sharif.edu/courses/93-94/2/ce342-1/resources/root/LectureNotes/… ·...

Multimedia Systems

Introduction

Hamid R. RabieeMahdi Amiri

February 2015

Sharif University of Technology

Course Presentation

Multimedia Systems, Introduction

Multimedia System

Review course website resources

Announcements, Password, Handling large files

Previous session


Multimedia System

Text

sms address to me.

Drawing

Let me see the bar chart for this data table.

Audio

Can’t chat, I have to call you.

Still image

See to believe.

Video

Wonder how it works.

Media

Also inside above categories: Graphs, Maps,

Animations, 3D Objects or Models, Diagrams, etc.


Multimedia System

Ascii art

Early printers often lacked graphics ability.

Ultrasonography

Visualizing subcutaneous body structures.

Spectrogram

Audio signal analysis.

Magnetic Resonance Imaging (MRI)

Media: Visual Representation


Multimedia System

Haptics

The sense of touch. It is a form of nonverbal

communication.

Hugging, Shaking hands, Vibration, Tickling.

Haptics are enabled by actuators that apply forces

to the skin for touch feedback, and controllers.

Common Haptic Feedback: Cause the handlebars

to vibrate during a collision with another vehicle in

racing video games.

Now are gaining widespread acceptance as a key

part of Virtual reality systems.

Media: Sense of Touch


Multimedia System

Example Haptics: Tactus Technology



Multimedia System

Why This Haptic Steering Wheel Could Save Your Life


Seth Porges, 2012-08-05 20:15:04 UTC

The car world's best hope for fighting in-car distractions can be summed up with one word: Haptics.

Haptics is the study of touch, and haptic feedback is when a device directs a sensation at you. You've felt this form of feedback

every time your smartphone has vibrated, or your Xbox controller has rumbled along with the explosions on the screen.

Here's how it involves cars. Since touchscreens don't have the feel of actual buttons, they require users to pay extra attention to

making sure they've pressed the right key. This is a particular problem for in-car touchscreens, since every second a driver's eyes are

off the road increases their chance of a collision. With haptic touchscreens, such as a prototype developed by California-based

Tactus Technology, the flat screen pops up into actual buttons when they're needed. Users would technically spend less time with

their eyes off the road. In other words, they'd be safer.

This is probably where the emphasis on haptic touchscreens as a safety measure sort of misses the point. The safest in-car systems

will keep your eyes on the road and your hands on the wheel. With haptic touchscreens, you still need to move your hands, and you

still need to at least glance their way.

This is why the prototype steering wheel that was jointly developed by researchers at AT&T Research Labs and Carnegie Mellon

University is so interesting. The steering wheel is embedded with a series of tiny motors, similar to the ones that cause you

cellphone to vibrate. As drivers get closer and closer to a turn, the motors cause the steering wheel to vibrate with increasing

frequency in a clockwise or counterclockwise pattern, depending on if it's a left or right turn.

According to Kevin Li, the AT&T researcher who developed the wheel, these vibration patterns trigger a “human perception trick”

that causes the brain to sense a number of discrete vibrations as a continuous line of motion. So you don't just feel a vibrating

steering wheel, but actually sense a clockwise or counterclockwise motion, which causes you to instinctively turn the steering wheel

along with it.

Li says his research has shown this has a noticeable impact on how much certain drivers keep their eyes on the road. “Interestingly,

this seemed to overload the senses of older drivers,” Li says. “But for younger drivers, eyes off the road as a proportion of driving

time decreased by about 10%.”

But sensing upcoming turns isn't all haptics can do. The same sensory trick that causes discrete vibrations to feel like a continuous

line can also be used to convey other, more complex types of information to drivers as well. For example, Li says that he is playing

around with a haptic seat that lets drivers "feel" a car pass through a blind spot. This sensory trick would allow the vibrations to tell

drivers where a car is, and how it is moving in relation to them.

The way I see it, this is basically a sort of “spidey sense,” where you instinctively feel the presence of on-the-road danger. And you

do it without moving your eyes, or your hands.

Source: http://mashable.com/2012/08/05/haptic-car-technology/ Turn when the steering wheel tells you

(AT&T Labs Research)


Multimedia System

MethodsAll computerized scent output systems work in the same way: the

computer, be it a full-featured desktop machine or a simple embedded

chip, sends a signal out through a serial or parallel port to a relay,

which turns on the output device itself for a designated period of time.

Media: Olfaction, The Sense of Smell

Nasal Ranger, an olfactometer, in use.

An olfactometer is an instrument used to detect and measure ambient

odor dilution. Olfactometers are used in conjunction with human

subjects in laboratory settings, most often in market research, to quantify

and qualify human olfaction (en.wikipedia.org/wiki/Olfactometer).

Scentography is the technique of creating and storing odor by

artificially recreating a smell using chemical and electronic means.

iSmell Personal Scent Synthesizer, one of

the "25 Worst Tech Products of All Time"

by PC World Magazine.


Multimedia SystemMedia: Olfaction, The Sense of Smell

Madeleine, a prototype of a desktop device to record aromas (Jul. 2013).

www.amyradcliffe.co.uk

en.wikipedia.org/wiki/Scentography

Click on image to play video.

Amy Radcliffe

Click on image to play video.

../Resources/Smell as Media/Madeleine/The Camera That Smells.mp4

../Resources/Smell as Media/Madeleine/MADELEINE A CAMERA THAT CAPTURES SMELL - technexo.blogspot.com.mp4


Multimedia System

Computer controlled integration of

different media

Text Audio Graphic

Drawing Still image Video

Haptics Animation

Every other type of

data representation forms

Multimedia…


Multimedia System

Where multimedia used to be … digitally.

Processed

Generated

Represented

Stored

Transmitted

Retrieved

Delivered

System


Multimedia System

HyperText

A text which contains links to other texts

Ted Nelson, 1965

Non-linear traversal

HyperMedia

Can include other media too

Text, HyperText, …, HyperMedia


Multimedia Systems

WWW

PowerPoint

Adobe Acrobat

iSilo

Text compression, Hyperlinks,

Images, Tables, Formatted text

ePUB

Free and open e-book standard

HyperMedia Examples

Tim Berners-Lee

first proposal for www: 1989


Multimedia Systems

HTMLNo version management, no rights management.

Project XanaduA word processor capable of storing multiple

versions, and displaying the differences between

these versions.

Find more at: http://transliterature.org/

ZigZagData Model, Database and visualization

system

See the movie at

http://xanadu.com/zigzag/

HyperMedia: True generalization!

Ted

Nelson

Computer documents are not just to

SIMULATE paper. They should

allow us to improve on paper.


Multimedia Systems

Computer controlled

IntegratedSeamless

Data are represented digitally

Interactive interfaceEnd-user is able to control the elements of media

Non-linear

Characteristics


Multimedia Systems

Digital representation

Analog to digital conversion, sampling.

Large data requirements

Storage, compression.

Distributed networks

Bandwidth, QoS.

Maintaining temporal relationship between data

Sequencing (playing frames in correct order/time frame in video).

Synchronization (inter-media scheduling, e.g. Lip synchronization).

Challenges


Multimedia Systems

Hardware

Very high processing power.

Efficient and high performance I/O.

Large storage and memory units.

Network support.

Software

Multimedia capable file system.

Special operating system.

User friendly software tools:

Easy to use, Easy to understand.

Network support.

Desirable Features


Multimedia Systems

Capture device

Video camera, Audio microphone, Keyboard

, Mouse, Tablet, OCR, different sensors.

Storage device

Hard-disk, CD-ROMs, DVD-ROM.

Communication Network

LAN, Intranets, Internet.

Computer System

Multimedia desktop machine.

Display Device

Speaker, Monitor, Printer.

Components


Multimedia Systems

World Wide Web.

Video conferencing.

Interactive TV, Video-on-demand.

E-learning, Hypermedia courseware.

Home shopping.

Games, Virtual reality.

Digital video editing and production systems.

Collaborative software , Groupware.

Edutainment, Infotainment.

Applications


Multimedia Systems

Format

Raw text, Rich text format.

Bitmap graphics (Image raster), Vector graphics.

Time independent (text), Time dependent (video).

Size

Typ. PAL digital video: 720 by 576 pixels for each one of 3 color

components, 25 frames per sec. ~ 30 MB per sec., ~ 104GB per

hour.

Standards

JPEG

MPEG-2, MPEG-4

Multimedia Data

largest capacity of a commercially

available HDD at the end of 2010


Multimedia SystemsGraphics Example

vector vs. raster (bitmap)

graphics

Raster graphics

Are composed of pixels.

.gif or .jpg

Data file contains: an array of pixels of

various colors.

Pro.: Small file size for lower resolutions.

Con.: Will become "blocky" if scaled up.

Vector graphics

Are composed of paths.

.eps file or Adobe Illustrator (.ai) file.

Data file contains: the points where the paths

start and end, how much the paths curve, and

the colors that either border or fill the paths.

Pro.: The images can be scaled to be very

large without losing quality (logos are typically

created in vector forma).

Con.: Not the best format for photographs.


Thank You

1. http://sharif.edu/~rabiee/

2. http://www.dml.ir/

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