MultimediaTechnology Image Technology

Krich Sintanakul271430 Multimedia and Hypermedia

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Types of Images

• Raster Image– Digitize or sampling from the real world– Store in bitmap orientation– Need large storage and High compression– Edit by retouching tool

• Vector Image– Synthesized image– Store in object structure list (Smaller)– Reusable , Scalable , Animating– No stair problem

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Types of Images

• Raster Image

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Types of Images

• Vector Image

(xmin,ymin)

(xmax,ymax)

01Object RectanPPPPP PPPPPP

Data (xmin,ymin,xmax,ymax) Rectangular (xmin,ymin,xmax,ymax)

begin lineto (xmin,ymin,xmax,ymin) lineto (xmax,ymin,xmax,ymax) lineto (xmin,ymin,xmin,ymax) lineto (xmin,ymax,xmax,ymax)

end end object

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Types of Images

• From vector to raster display system

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Displaying Image in Computer

• - Cathode Ray Tubes and LCD panel

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Displaying Image in Computer

• Source of color

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Displaying Image in Computer

• Source of color in CRT

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Displaying Image in Computer

• Color Mixing in RGB model

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Displaying Image in Computer

• Raster scan display system

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Displaying Image in Computer

• Raster scan display system

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Displaying Image in Computer

• Color Raster scan display system

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Displaying Image in Computer

• Raster scan display system

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Type of color display system

• True Color system– 2416/ Bits each pixel– 3 /2 Bytes per pixel– PPPP PPPPP PPPPPPPPP PP PPPP P PPPPPP

• Index Color system– 8 (1 )bits byte per pixel– PPPP PPPPP PPPPP PP P PPP P2 56– Keep address of table in Frame buffer

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Type of color display system

• True Color system

N

M

Bit depthVideo

controller CRT

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Type of color display system

• True Color system– VGA 2 4 Bits 6 4 0 * 4 8 0 = 3 0 7 2 0 0 Pix

els = 9 2 1 6 0 0 Bytes– PPP1 6 6 40*480 307200

els = 6 1 4 4 0 0 Bytes– PPPPP24 800*600 = 480000 =1 440000– 16 800*600 480000SVGA Bits = Pi

xels = 9 6 0 0 0 0 Bytes

1 Byte 1 Byte

1 Byte 1 Byte 1 Byte

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Type of color display system

• Index Color system

P

y 501

01001

Color TableR G B

0

255

00

01001010010011110001101050

3 8 24colors x bits/column = bits

///

P

P 8 bits Frame Buffer

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Type of color display system

• Index color system– 256 640*480 307200 307VGA Color = Pixels =

200 Bytes PPPPP2 5 6 * 3 (2 4 ) 7 6 8

PPPPP307200 + 768 = 307968

– PPPPP256 800*600 = 480000 =4 80000 256*3 24 768Index table ( bits) Bytes

480000 768 480768Total + = Bytes

– 256 1024*768 786432 7SVGA Color = Pixels = 86432 Bytes

256*3 24 768Index table ( bits) Bytes

786432 768 787200Total + = Bytes

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How to display an image file(1)

• BMP indexed file structure

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Howt o di spl ay an i mage fi l e(2 )

• Step 1 Load image information

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How to display an image file(3 )

• Step2 Load col or i ndex t o vi deo pal let

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How to display an image file(4 )

• Step 3 Load pixel information by lookup color pallet