Multimedia Elements II Graphics, Digital Video. UIT - Multimedia Production2 Multimedia Elements Multimedia elements include: Text Graphics Animation.

Multimedia Elements II

Graphics, Digital Video

UIT - Multimedia Production2

Multimedia Elements Multimedia elements include:

Text

Graphics Animation

DigitalVideo

DigitalAudio

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Multimedia Elements

Graphics Graphics is a digital representation of non-text informatio

n such as a drawing, chart, or photograph. It is also called a digital picture or image, and contains n

o movement or animation 3 fundamental characteristics of color

Hue (色調 ) Related to the wavelength of light

Lightness (亮度 ) Related to the amplitude of light

Saturation (彩度 ) Related to the purity of light


Multimedia Elements

GraphicsPixel A pixel is the smallest unit of programmable color on a

computer display or in a computer image Every computer graphic is made up of a grid of pixels There are two types of graphics

Bitmap graphics Vector graphics


Multimedia Elements

GraphicsBitmap Graphics Bitmap is a representation of a graphics image Consists of rows and columns of dots The value of each dot (whether it is filled in or not) is

stored in one or more bits of data Simple monochrome images use one bit to represent

each dot


Multimedia Elements

GraphicsBitmap Graphics The more bits used to represent a dot, the more colors a

nd shades of gray that can be represented:

1-bit image, 2 color: black or white

8-bit image, 256 colors (28=256)

24-bit image, 16777216 colors (true color)


Multimedia Elements

GraphicsVector Graphics Vector graphics are based on mathematical formulas

that represent curves and lines Very smooth looking and can easily be resized without

loss of image quality

Bitmap Vector

00000000000000 {(3, 2) (10, 2)}

00111111111100

00000000000000

00000000000000


Multimedia Elements

GraphicsVector Graphics An example of vector graphic is the clipart in MS PowerP

oint When you enlarge a clipart image, it will not distort


Multimedia Elements

GraphicsResolution Determines how sharply the image is represented Expressed in dot per inch (dpi), or simply by the number

of rows and columns, such as 640 by 480 Bitmap graphics suffer distortion in image quality when

being scaled up, this does not happen in case of vector graphics

Bitmap graphic Vector graphic


Multimedia Elements

GraphicsFormats A format is a standard

specifying how the data is arranged

For bitmap graphics BMP GIF JPEG

For vector graphics AI FH WMF


Multimedia Elements

GraphicsFormats BMP (.bmp)

Microsoft's native graphic file format GIF (Graphic Image Format) (.gif)

Only supports 256 colors; It serves as compressed web graphics. GIF works best when the number of colors within an image is small

JPEG (Joint Photographic Experts Group) (.jpg) Supports millions and allows for graphic compression. Most people use

JPEG for Web graphics that contain a multitude of colors and gradations - like photographic images

AI (Adobe Illustrator) (.ai) For graphics produced by Adobe Illustrator

FH (FreeHand) (.fh) For graphics produced by FreeHand

WMF (Windows Metafile Format) (.wmf) For exchanging graphics between Microsoft applications such as clipart

in Microsoft Office


Multimedia Elements

GraphicsGIF versus JPEG When the number of color of an image is large, JPEG

performs better

JPEG format, 6k bytes GIF format, 13.5k bytes


Multimedia Elements

GraphicsGIF versus JPEG When the number of color of an image is small, GIF

performs better

GIF, 1.5k bytes

JPEG, 5.4 bytes


Multimedia Elements

Computer-based AnimationAnimated GIFs Animated GIFs are a special kind of GIF file known as GIF89a An animated GIF file stores multiple images as separate blocks withi

n a single GIF file When being viewed on the Web, the multiple images are streamed

(played back one at a time) Streaming: the viewer does not have to wait for the entire GIF to be

downloaded before it begins running on a Web page

Multimedia Elements II Graphics, Digital Video. UIT - Multimedia Production2 Multimedia Elements Multimedia elements include: Text Graphics Animation.

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