1. Graphics (image)

2. Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
Menunjukkan Penggunaan Gambar pada Aplikasi Multimedia

3. Outline Materi What is an Image Image Media Types Bitmap Image
Vector Image
3-Dimensional Graphic Models
Working With Graphics

4. What is an Image?
An image is the graphical and visual representation of some information that can be displayed on a computer screen or printed out
Images come in a variety of forms:
Photographs
Drawings
Paintings
Television and motion pictures
Semantics
Maps, etc.
Images play an important part in multimedia
Navigation
User interface components
Help systems
Clip art

5. Image Media Types Images can be generally divided into two formats:
Bitmapped or Raster images
Draw-type or Vector graphics or Metafile images
Bitmapped images are stored as an array of pixels. It represents the image as an array of dots, called pixels
Vector graphics are stored as geometric shape to represent the image

6. Bitmaps Image
A pixel is the smallest element of resolution on a computer screen (Screen Resolution)
A pixel is the basic unit of a digital images. Digital image is a picture that may be stored in, displayed on, processed by a computer.
As mentioned, bitmap is composed of a matrix elements called pixels
Each pixel can be in a specific colour and each pixel consists of two or more colors.

7. Bitmaps Image The range of these colours is known as the colour depth.
The color depth determined “How much data in bits used to determined the number of colors”.
Colour depth is measured in bits per pixel
Remember: a bit (binary digit) is either 1 or 0 and that there are eight (8) bits in a byte

8. Colour depth 1 bit per pixel = 2 colours (monochrome)
2 bits per pixel = 4 colours
4 bits per pixel = 16 colours
8 bits per pixel = 256 colours
Generally good enough for colour images
16 bits per pixel = colours
Better quality for photograph-like images, also known as high colour
24 bits per pixel = >16 million possible colours
Used to recreate photo realistic images, also known as true colour

9. Bitmaps Image
The more colours that are allowed per pixel, the greater the size of the image
The number of pixels is related to the size of file that required to store an image.
Remember, two factors effect the size file bitmap are:
Resolution
Color Depth

10. Bitmaps images
Original image
Shown
magnified

11. Image (Bitmap)
pixel

12. Image Total number of pixels is HxV Every pixel represented by
1 bit (bw)
1 byte (greyscale)
1 byte (256 color)
2 byte (64K color)
3 byte (16M color)
Pixel
H (horizontal number of pixel)
V (vertical number of pixel)
IWAN SONJAYA, ST.MMT,MT

13. Greyscale Image (1 byte per pixel)
Image 500 x 400 pixel
Total number of pixel is pixel
Each pixel represented by 1 byte
Total image capacity x 1 byte = byte
Pixel-2
Pixel-n
= 1 byte
Pixel-1

14. Color Image (true color, 3 byte per pixel)
Image 400 x 500 pixel
Total number of pixel is pixel
Each pixel represented by 3 byte
Total image capacity x 3 byte = byte
Pixel-1
Pixel-2
Pixel-n
= 1 byte

15. Color vs Greyscale vs BW
Black and White

16. Black and White (1 bit per pixel)
8 pixels
8 pixels
= 1 byte
8 pixels
Greyscale
Black & White

17. Calculating the size of a raster image
Where:
Width of the images measured in pixels
Height of the images measured in pixels
Colour depth is the number of bits used for color measured in bits per pixel
Remember:
1024 bytes = 1 kilobyte (KB)
1024 kilobytes = 1 megabyte (MB)

18. Example
A 640 x 480 pixel image in 24-bit colour would require how much disk space?

19. Popular bitmap formats
Microsoft bitmap (.bmp)
Used in microsoft windows
TIFF - Tagged Image File Format (.tif)
Used for faxing images (amongst other things)
JPEG - Joint Photographic Expert Group (.jpg)
Useful for storing photographic images
GIF - Graphics Interchange Format (.gif)
Used a lot on web sites
PNG - Portable Network Graphics (.png)
A new format for web graphics
PCD – Kodak photo CD
A new format for store image in a compressed form on a CD

20. Advantages and Disadvantages of using bitmap images
Convey detail of information quickly
Real life
Disadvantages
Depend on a Resolution
Effect to the image quality
Size file is big

21. Software to create bitmap images
Popular PC packages include:
Microsoft Paint
Included with microsoft windows
Microsoft PhotoDraw 2000
Adobe Photoshop
Paint Shop Pro
Macromedia Fireworks

22. Vector images
Vector images are stored as the set of graphic primitives required to represent the image
A graphic primitive is a simple graphic based on drawing elements or objects such as shape
e.g. square, line, ellipse, arc, etc.
The image consists of a set of commands (mathematical equations) that are drawn the object when needed.

23. Vector images
Storing and representing images by mathematical equations is called vector graphics or Object Oriented graphics.
Each primitive object has various attributes that go to make up the entire image
e.g. x-y location, fill colour, line colour, line style, etc.
Example:
RECTANGLE : rectangle top, left, width, height, color is ( 0, 0, 200, 200, red)
CIRCLE : circle top, left, radius, color
LINE : Line x1, y1, x2, y2, color

24. Vector images
Vector image or vector graphics can be resized without losing the integrity of the original image.
Scaling a vector is a mathematical operation - only the attributes change, the image is unaffected

25. Primitive geometric drawing objects
Basic
Line
Polyline
Arc
Bezier curve
Text
Font, weight
Shapes
Circle
Ellipse
Rectangle
Square
Pie segment
Triangle
Pentagon, hexagon, heptagon, octagon, etc

26. Scaling vector graphics
Shown
magnified
Original image

27. Advantages and Disadvantages of using vector image
Relatively small amount of data required to represent the image.
Therefore, it does not required a lot of memory to store
Easier to manipulate
Disadvantages
Limited level of detail than can be presented in an image

28. Software to create images
Graphics programs are tools that allow an artist to create and edit designs used in multimedia applications.
Generally, graphics programs can be categorized as:
Drawing programs
Creating draw type graphics
Provide freehand. Example geometric shape
Example : Adobe Illustrator, Corel Draw, Macromedia Freehand
Paint programs
Those creating bitmaps
Useful in creating original art
Example: Paint Shop Pro
Image editing programs
Making changes to existing images, such as manipulating the brightness or contrast, applying textures, patterns
Examples : Adobe Photoshop, Corel PhotoPaint

29. Vector formats Windows metafile (.wmf) Used by Microsoft Windows
SVG - Scalable Vector Graphics (.svg)
A new format devised for the web
CGM - Computer Graphics Metafile (.cgm)
Older format commonly used for clip art
Adobe PostScript (.ps)
A page description language used to control printers
Adobe Portable Document Format (.pdf)
A page description language common on the web
Drawing Exchange Format (.dfx)
Store 3D image created by design program AutoCAD
Encapsulated PostScript (.epf)
Professional printing: Illustration program, Adobe Systems, Desktop Publishing programs

30. 3-Dimensional Graphic models
A 3D model is a variation on the vector format
The location of a 3-dimensional object is specified using x, y and z co-ordinates
Further primitives can be found in 3D models
Cube, sphere, pyramid, etc.
Camera, spotlight, texture, shading etc. X
3D model Y Z

31. 3-Dimensional Graphic models
3D graphics offer the photorealistics effects that have you seen in TV, Computer Games
Examples, Motion Picture films such as:
Jurassic Park, Terminator 2, Lost World and Toy Story
Examples 3D programs:
Carigali Truespace
3D Studio Max
Infini-D

32. 3-Dimensional Graphic models

33. Hardware used to acquire images
Scanners and digital imaging products
Many forms of scanner
Drum
Flat-bed
Negative / slide
Hand-held
Important to check the optical resolution of the scanner
measured in dots per inch (DPI)

34. Hardware used to acquire images
Digital camera
Uses digital memory instead of film
Images are transferred to computer via a cable
Can be very high resolution
Stills from a camcorder or PC “web-cam” type camera
Home products tend to be low resolution

35. Hardware used to create / edit images
Graphics tablet and pen
Preferred by digital artists
Pressure sensitivity
Digitiser tablet
Preferred by technical artists
Mouse has accurate crosshair to help digitise drawings
Tablet and pen
Digitiser

36. Converting image formats
TrueType / PostScript Type font
Bitmapped font
Render as bitmap
Text
Bitmapped image
Vector image
Contour trace
Optical Character
Recognition (OCR)

37. Working With Graphics
Considerations and guidelines when we are working with graphics:
Choose the graphic depend on your work
Choose the correct software
Use minimum color depth
Delivery Systems

38. How graphics/images can be used effectively
Different types of graphics are used in different ways:
Line drawing are graphical representations of physical objects. There are 3 kinds of line drawings:
Isometric - represent 3-D objects without realistic perspective
Orthographic - are 2-D representations of objects
Perspective - represent objects in their most realistic form

39. How graphics/images can be used effectively ?
Graphs and Tables
In just a glance, graphs can provide specific data, show general trends in data or depict the relationships between data and data trends
Diagrams
Help users conceptualize a process, flow or interrelationship. Examples of diagrams include: Flow charts, Schematic Drawings and Block Diagrams.

40. Advantages and Disadvantages of using images
Convey a lot of information quickly
Add visual simulation and colour
Can communicate across language borders
Enhance other media
Disadvantages
Do not provide in-depth explanations
Graphics rarely suffice to convey a whole message in business, technical or safety settings
Can be misinterpreted
Graphics should be used carefully to make sure the message is not ambiguous or cryptic

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