Understanding Multimedia Systems and Data Processing
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Explore the components and functions of multimedia systems, handling both time-independent and time-dependent media streams. Learn about compression, encryption, enhancement, and recognition techniques. Discover the history of bandwidth in computer networks and the network requirements for different data streams.
Understanding Multimedia Systems and Data Processing
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Presentation Transcript
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.)
Time-Independent Media • Example (Image)
Time-Independent Media • Example (Image) Who is angering you?
Time-Independent Media • Example (Image) Who is sad?
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 • 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
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
Encryption • Example
Encryption • Example
Encryption • Example (Decryption)
K K A-B A-B K (m) m = K ( ) A-B A-B Encryption • Text/String encryption algorithm decryption algorithm ciphertext plaintext plaintext message, m K (m) 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.
PowerPoint • Example
PowerPoint • Example
PowerPoint 48
App • http://processing.org/tutorials/android/