1 revision. 2 multimedia systems 2 lecture 1 - introduction to multimedia lecture 2 - perception...

27
1 Revision

Upload: abel-hunt

Post on 29-Dec-2015

228 views

Category:

Documents


2 download

TRANSCRIPT

Page 1: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

1

RevisionRevision

Page 2: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

2

Multimedia Systems 2Multimedia Systems 2 Lecture 1 - Introduction to Multimedia Lecture 2 - Perception (Light and colour, true and palette colour) Lecture 7 - Image Formats (vector/bitmap, GIFF, JPEG etc.) Lecture 3/4 - The Internet & Networked Multimedia Lecture 5 - The World Wide Web Lecture 6 - Web Pages Lecture 8 - Digital Video (MPEG) Lecture 9 - Streaming Video Lecture 10 - Multimedia Design Lecture 11 - Video Displays Lecture 12 - Display Adapters Lecture 13 - Graphics Lecture 14 - 3D Graphics Accelerator Cards & APIs Lecture 15 - Communications Theory

Page 3: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

3

PerceptionPerception

Electromagnetic spectrum

Page 4: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

4

Colour Sources/DisplaysColour Sources/Displays

TypesActive sources - monitorsPassive sources - printed documents

Primary Colours (RGB,CMY)

Principle of Operation

Page 5: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

5

Colour Models Colour Models

Colour GamutHuman Colour SensitivityOther Colour Models

HLSHSV

Page 6: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

6

True Colour Image Data Model

True Colour Image Data Model

Y

X

Pixel

Image

R G B

Colour

Page 7: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

7

Palette Colour Image Data Model

Palette Colour Image Data Model

Y

X

Pixel

Image

Index

R G B

Palette

R G B

Colour

165 16 49

R G B

Page 8: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

8

True colour Vs. Palette colour

True colour Vs. Palette colour

True Colour:High qualityExpensive hardwareRequire more memory (normally 3 times)

Palette ColourLimited number of coloursCheap hardwareEnables easier implementation of certain

techniques

Page 9: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

9

Image FormatsImage Formats

Two principle methods of representing graphical dataVectorsBitmaps (raster or pixel maps)

• Lossless Compression

• Lossy Compresion

Advantages/Disadvantages

Page 10: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

10

Graphics Interchange Format (GIF)

Graphics Interchange Format (GIF)

Advantages/DisadvantagesFile FormatFunction of each sectionAnimatedTransparent

GIF Signature

Screen Descriptor

Image Descriptor

Global Colour Map

Local Colour Map

Image Data

GIF Terminator

Repeated 1 to n times

Identifies GIF and format

GIF87A or GIF89A

Page 11: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

11

Joint Photographic Experts Group

Joint Photographic Experts Group

JPEGAdvantages/DisadvantagesJPEG stagesApproximate compressionProblems of over-compression

Page 12: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

12

The Internet & Networked Multimedia

The Internet & Networked Multimedia

Interconnected set of networks Design principles

Interoperability Uniform naming and addressing Layering SimplicityEnd-to-end protocols

Page 13: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

13

Uniform naming and addressing

Uniform naming and addressing

The IP 32-bit addressing structure139.184.14.13

Domain Name Servers (DNS)PurposeFunctionDNS process

Domain Names IP addresses

Classes

Page 14: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

14

LayeringLayering

Reason for using layered systemFunction of each layer

Application Layer (e.g. HTTP, SMTP)

Transport Layer (TCP, UPD)

Physical Layer (e.g.Ethernet)

Network Layer (IP)

Page 15: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

15

Internet ProtocolInternet Protocol

The main functions of IP IP Datagrams and packets in general

Datagram structureIP SecurityRouters

M

Version Header Length Type of service

Total Length

Identification

Fragment OffsetD

Time-to-live Protocol

Source IP Address

Header checksum

Data (<=64kB)

Options

Destination IP Address

Header

Page 16: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

16

Transmission Control Protocol (TCP)

Transmission Control Protocol (TCP)

What does it provide that IP doesn’t?PurposeOperation

TCP connection set-up

Source port

Destination port

Sequence Number

Acknowledgement Number

Data

Urgent Pointer

Data offset

Reserved Flags

Window

Checksum

Header

Page 17: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

17

Web PagesWeb Pages

StaticHTMLSHTML

DynamicNSFASPPHPCGI

Server side and Client side scripting

Page 18: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

18

Digital VideoDigital Video

Moving Picture Experts Group MPEG2OperationCompression

I B B P B B P B B I

Page 19: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

19

Video DisplaysVideo Displays

Display technologyCathode Ray TubeFlat panel displays

• Liquid Crystal (LCD)

OperationAdvantages/Disadvantages

Page 20: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

20

General operation Function of:

Electron gunsPhosphors Raster scanShadow mask /

Aperture grill

Colour CRT DisplaysColour CRT Displays

Page 21: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

21

CRT DisplaysCRT Displays

Dot pitchResolutionScanning

InterlacedNon-interlacedFrame/ Refresh rateScan rateDot clock

Screen sizesScreen Curvature

Page 22: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

22

Colour Liquid Crystal Displays

Colour Liquid Crystal Displays

Light source ReflectedGenerated

• backlit• edgelit

Operation of a Colour LCDNematic TechnologyPassiveActive

Page 23: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

23

GraphicsGraphics

2D GraphicsVectorBitmap

3D GraphicsCoordinate system X,Y,Z Geometry dataTexture dataDefining 3D objectsGraphics Pipeline

Page 24: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

24

Defining 3D ObjectsDefining 3D Objects

Objects in the 3D scene and the scene itself are transformed through five spaces when proceeding through the 3D pipelineModel SpaceWorld SpaceView SpaceClip SpaceScreen Space

Function of each

                            

                       

Page 25: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

25

View Frustrum and ClippingView Frustrum and Clipping

View frustrumPurposeOperation

ClippingPurposeOperation

Perspective divide

Page 26: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

26

Graphics PipelineGraphics Pipeline

Purpose and OperationStages

Application/SceneGeometry

• Translation

• Rotation

• Scaling

• Skewing

Triangle Set-upRasterization / Rendering

Page 27: 1 Revision. 2 Multimedia Systems 2  Lecture 1 - Introduction to Multimedia  Lecture 2 - Perception (Light and colour, true and palette colour)  Lecture

27

FinFin

Fin