Multimedia Tech

Introduction to

Multimedia TechnologyCourse

Ghifar

Overview Multimedia course in

Informatics Engineering UNPAR

Introduction to Multimedia

Compression: A handy invention

MULTIMEDIA COURSE@ INFORMATICS ENGINEERING UNPAR

Multimedia Tech. Course

What will you learn ? Graphics/Image, Audio, and Video

Representation

Compression Algorithms and Techniques

Compression Standards

JPEG, H.261, MPEG, etc

Digital Rights

State-of-The-Art Multimedia TechVoIP

Video conference

INTRO TO MULTIMEDIA

What is Multimedia ? When different people mention the term multimedia,

they often have quite different, or even opposing, viewpoints A PC Vendor : a PC that has sound capability, a DVD-ROM

drive, and perhaps the superiority of multimedia-enabled microprocessors that understand additional multimedia instructions

A consumer entertainment vendor: interactive cable TV with hundreds of digital channels available, or a cable TV-like service delivered over a higher speed internet connection

A Computer Science (CS) student: applications that use multiple modalities, including text, images, drawings (graphic), animation, video, sound including speech, and interactivity

Multimedia and CS : Graphics, HCI, visualization, computer vision, data

compression, graph theory, networking, database systems

Components of Multimedia Multimedia involves multiple modalities

of text, audio, images, drawings, animation, and video. Examples of how these modalities are put to use:

Video teleconferencing

Distributed lecturers for higher education

Tele-medicine

Co-operative work environments

Searching in (very) large video and image databases for target visual objects

Augmented reality: placing real-appearing computer graphics and video objects into scenes

Components of Multimedia (2)

including audio cues for where video-conference participants are located

build searchable features into new video, and enabling very high-to very low bit-rate use of new, scalable multimedia products

Making multimedia components editable & distributed

Video understanding => “Inverse-Hollywood”

Using voice & speech Recognition to build an interactive environment, say a kitchen-wall web browser

Multimedia Research Multimedia processing & coding

multimedia content analysis, content-based multimedia retrieval, multimedia security, audio/image/video processing, compression, dll

Multimedia system supports & networking

network protocols, internet, operating systems, servers and clients, quality of service (QoS), databases

Multimedia tools, end-systems & applications

hypermedia systems, user interfaces, authoring systems

Multi-modal interaction and integration

“ubiquity” – web-everywhere devices, multimedia education (Computer Supported Collaborative Learning), design and applications of virtual environments

Current Multimedia Projects

1. Camera-based object tracking technology

2. 3D motion capture :used for multiple actor capture so that multiple real actors in a virtual studio can be used to automatically produce realistic animated models with natural movement

3. Multiple views : allowing photo-realistic (video-quality) synthesis or virtual actors from several cameras or from a single camera under different lighting

4. 3D capture technology : allow synthesis of highly realistic facial animation from speech

Current Multimedia Projects (2)

5. Specific multimedia applications : aimed at handicapped persons with low vision capability and the elderly – a rich field of endeavor

6. Digital fashion : aims to develop smart clothing that can communicate with other such enhanced clothing using wireless communication, so as to artificially enhance human interaction in a social setting

7. Electronic Housecall system : an initiative for providing interactive health monitoring services to patients in their homes

8. Augmented Interaction applications : used to develop interfaces between real and virtual humans for tasks such as augmented reality

Let’s watch some interesting videos ….

Compression : A handy invention

That handy invention can answer the questions here

Do you eager to know :

How does the ZIP/RAR application work?

How can images be sent and loaded fast via Internet ?

Why can the VoIP be implemented ?

How can video be streamed through the relatively narrow communication lines ?

The obvious example Suppose we have a string :

“ABCCCCCCCCDEFGGGG“ (17 characters)

By exploiting some redundancies, we can rewrite that string so that become : “ABC!8DEFG!4” (now only 11 characters)

“!” refers to the next character is the frequency of the previous character

Min. 4 same consecutive chars

Is there any disadvantage ?

Run-Length Coding (RLC)

“Ask not what your country can do for you - ask what you can do for your country”

- John F. Kennedy -“ask” appears 2 times“what” appears 2 times“your” appears 2 times“country” appears 2 times“can” appears 2 times“do” appears 2 times“for” appears 2 times“you” appears 2 times

The Second Example: note this famous quotation below…

How can we compress the quotation ?

One of the method is using the “dictionary”

Supposed this is our dictionary :

Our sentence now reads :

Lempel & Ziv adaptive dictionary-based

What about compressing other multimedia besides text ?

The 2 previous compression techniques are simply not enough to compress multimedia data such as image, audio, or video

For others, sometimes they need more sophisticated encoding algorithm or advanced math. computation to compress more data

Discrete Cosine Transform (DCT)

Karhunen-Loeve Transform (KLT)

Continuous Wavelet Transform (CWT)

Discrete Wavelet Transform (DWT)

Embedded Zerotree of Wavelet Coefficients (EZW)

The Principals of Compression

From previous examples, we can summarize 2 main factors :

1. Data Redundancy Number of repetitions/occurrences,

spatial redundancy, temporal redundancy

2. Human Perception Generally, human perception is not

sensitive with small errors

Have an error tolerance without really affecting the effectiveness of the communication

Types of Compression1. Lossless Compression

You have already seen the example The compression result must able to

be decompressed ! But, it’s not really small enough e.g. : ZIP, RAR, GZIP, binary program,

some of GIF and PNG images

2. Lossy Compression The compression result needs not to

be decompressed It’s enough to be used the smaller

form The result size is far smaller than

“the lossless” e.g. : JPEG, MP3, MPEG

Is there any difference ?

Summary for Compression

Compression is the process of encoding information user fewer bits than the original

Reduce the consumption of expensive resources, such as hard disk space or transmission bandwidth

There are numerous methods of compression techniques which some of them are suitable with the specific multimedia data and others are not.

Principals of compression : Data Redundancy and Human Perception

Types of compression : Lossless and Lossy

ANY QUESTION

THANK YOU