introduction tsung-yi wu introduction what is a multimedia system? –a multimedia system supports...
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Introduction
Tsung-Yi Wu
Introduction What is a multimedia system?
– A multimedia system supports the integrated storage, transmission and representation of the discrete media types text, graphics and image and the continuous media types audio and video on a digital computer.
A Hybrid (analog/digital)
Multimedia System Early multimedia system, around 1985
Digital Multimedia System
The media streams are digital. They can be processed (e.g., compressed/ decompressed,analyzed) in the computer.
Time-Independent Media
Information is not related to timing of the data stream
All „classic“ media in the computer, such as:– text– graphics (line drawings, vector graphic)– image (photo, pixel graphics).
Time-Independent Media
Example [Kitaoka 2003]
Time-Independent Media
Illusory Motion (Ming-Te Chi et al.)Ming-Te Chi et al.)
Time-Independent Media
Example (Image)
Time-Independent Media
Example (Image)
Time-Independent Media
Example (Image)
Time-Independent Media
Hybrid Image– http://cvcl.mit.edu/publications/
publications.html
Time-Independent Media
Example (Graph)
Time-Independent Media
Example (3D Stereogram)
Time-Independent Media
Example (How to see, 14 cyclic stones)
Time-Independent Media
3D Stereogram – DIY
http://www.flash-gear.com/stereo/
Why do they look 3D? – http://www.kondo3d.com/stereo/why-3d/
why-3d-e.html Paper
Time-Independent Media
Why do they look 3D?
Time-Independent Media
Example (3D ASCII Stereogram)
Time-Independent Media
Example (3D ASCII Stereogram)
Time-Independent Media
Optical Illusion– http://www.johnsadowski.com/
big_spanish_castle.php
Time-Dependent Media
Information is time-related, must be shown to the user at specific points in time
Continuous data streams– Data appears in regular intervals
Examples:– Video (continuous)
Time-Dependent Media
Examples:– An animation (not a continuous stream,
but time-dependent)
– An interactive game on the Internet (not a continuous stream, but has real-time requirements)
– Audio (continuous)
Time-Dependent Media
Image Morphing – Morphing is a special effect in motion pictures and
animations that changes (or morphs) one image into another through a seamless transition.
Morph Tools– FantaMorph– Fun Morph
Time-Dependent Media
3D Stereogram Movie in Ascii http://www.kammerl.de/ascii/AsciiStereoMovie.php
3D Animated Stereograms – http://www.hidden-3d.com/
stereogram_theory.php
Multimedia System Integrated
production,processing,storage,representation, Transmission, etc.
of several time-dependent and time-independent media streams
History of Bandwidth in Computer Networks
Network Requirements of Different Types of
Data Streams
Multimedia Processing Compression/Decompression Encryption/Decryption Enhancement Transformation Recognition Etc.
Compression Goal
– The compression of multimedia data streams saves
storage space transmission
bandwidth
Compression Lossless
– If the recovered data are assured to be identical to the source
– Lossless compression techniques are requisite for applications involving textual data
e.g. ZIP
Lossy– Other applications, such as those involving voice
and image data, may be sufficiently flexible to allow controlled degradation in the data
Compression Lossy
– Example (DCT) Although there is some loss of quality in the reconstructed
image, it is clearly recognizable, even though almost 85% of the DCT coefficients were discarded.
Encryption Example
3
1
0
2
Encryption Example
Encryption Example
Encryption Example (Decryption)
Encryption Text/String
plaintextciphertext
KA-B
encryptionalgorithm
decryption algorithm
KA-B
plaintextmessage, m
K (m)A-B
K (m)A-Bm = K ( )
A-B
Enhancement Examples
Transformation Example
Transformation Example
– Original – Changed
Recognition Example
Tools Matlab
I = imread('cameraman.tif');I = im2double(I);T = dctmtx(8);B = blkproc(I,[8 8],'P1*x*P2',T,T');mask = [1 1 1 1 0 0 0 0 1 1 1 0 0 0 0 0 1 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0];B2 = blkproc(B,[8 8],'P1.*x',mask);I2 = blkproc(B2,[8
8],'P1*x*P2',T',T);imshow(I), figure, imshow(I2)
Tools Matlab
Tools PhotoImpact
Tools Audacity
FrontPage HTML Javascript
function encode() { if(document.form2.R1[0].checked){ Result="0 分 "; } if(document.form2.R1[1].checked){ Result="30 分 "; }document.form1.S1.value=Result;}
Java
Anfy Anfy (Java™) includes 52 applets, top
effects and menu for web sites and blogs. Plus screensaver.
Flash MX
PowerPoint Example
PowerPoint Example
PowerPoint
49
App http://processing.org/tutorials/android/