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coursenote:005

<note important> 本节编撰作者(鼓励有兴趣的同学自由撰写,总评成绩可适当加分):

  • 张三 (3080100999), 编写了…

浙江大学2008-2011版权所有,如需转载或引用,请与 作者联系。 </note>

What is Multimedia: –To distribute and present information coded as • Text, Graphics, animation, audio and video.. –By • Computer, TV, phone, etc.

a number of key aspects of multimedia: –Multimedia involves “Many Media” • THE MEDIA DOMAIN –Multimedia involves Computers • THE SYSTEMS DOMAIN –Multimedia enhances the presentation and communication of information • THE APPLICATION DOMAIN


Why do we need multimedia? 1.A computer database supports many basic data types: 2.Inadequate to hold documents such as letters, application forms or image (student photograph). 3.Need a document image processing system including: 4.Further enhancement to handle other types of information (voice)A short video clip

Media types can be divided into two groups: Temporal media types: • audio, video, music, animation Non-temporal media typ • text, graphics, images


Media Type: TextDifferent Representation

ASCII
ISO character sets
Marked-up text
Structured text
Hypertext

Media Type: Image Different Representation

Color model
Alpha channels
Number of channels
Channel depth
Interlacing
Indexing
Pixel aspect ratio
Compression

Media Type: Graphics: Different Representation

Geometric models
Solid models
Physically based models
Empirical models
Drawing models
External format for models

Media Type: Analog Video:

Different Representation
Frame rate
Number of scan lines
Aspect ratio
Interlacing
Hypertext
Quality
Component/Composite

Media Type: Digital Video: Different Representation

Sampling
Sampling rate
Sampling size and quantization
Data rate
Frame rate
Compression
Support for interactivity
Scalability

Media Type: Videos Media Type: Digital Audio Media Type: Audio

Media Type: Music Different Representation

Operational/Symbolic
  MIDI
  (Musical Instrument Digital

Interface)

Media Type: Animation Different Representation

Cel models
Scene-based models
Event-based models
Key frames
Articulated objects and hierarchical

models

Scripting and procedural models
Physically based and empirical 

models


Characteristics of MM Data – challenges about managing MM data Huge Size Data Volume Similarity-based Search Quality of Service (QoS) Synchronization Content-Based Retrieval Temporal Aspects Media Representation


Characteristics of MM Data – challenges about modeling MM data 1.High level content abstraction is natural to the way humans think 2.Effective modeling of MM data is critical 3.Low level representation of multimedia data, which encodes the physical reality, leads to the problem of huge amounts of data. 4.Another reason for introducing abstractions (providedby the user/system) is to allow the user to refer to the data in terms of abstractions which make up his modeof the application domain.


MMDBMS –a framework that manages different types of data potentially represented in a wide diversity of formats on a wide array of media sources

Uniformly query data represented in different formats Query data represented in diverse media Retrieve media objects from a local storage devices in a smooth, jitter-free manner Provide audio visual presentation of a query result Deliver presentation to satisfy quality of service requirements


Multimedia equation Multimedia = presentation + context presentation: sensory, aesthetic part (美学)

context = convergence + information + architecture • convergence = data +platform + distribution • information = storage and retrieval • architecture = compression + components + connectivity

coursenote/005.txt · Last modified: 2015/11/13 08:49 (external edit)