1. Multimedia Building Block
Presented by GHOLAMREZA KAKAMANSHADI
Panjab university
Nov. 2013

2. Multimedia Building Block
Digital environment
USER
Multimedia is a combination of various elements, such as text, images, video, sound, and animation.
Interactive multimedia allows the user to control what and when the elements are delivered
Elements of Multimedia

3. Text in history Written text came into use about 6000 years ago
Initially text was written in symbols
- Pictographic signs and cuneiforms

4. Text in Multimedia A key component of any multimedia product
Multimedia product depends on text for various reasons
Page title
Content of the information
Label and instruction
etc.

5. The power of meaning… Word must be chosen carefully
Precise and accurate meaning to describe what you mean
Word must be chosen to illustrate to a few meaning
Word appears in titles, menus and navigational aids.
Test the words that you plan to use on several users and observe their reaction.

6. Types terminology ARIAL Courier Times New Roman
Typeface: a family of similar characters that may include many sizes and styles
ARIAL
Courier
Times New Roman

7. Font: characters of a single size and style, which are part of the same fontface family
Arial – Arial Italic – Arial size 28
Arial Narrow
Times – Times extra – Times bold
Style: attributes of a font, such as italic, bold, underline, shadow etc.

8. Point: the font size is usually measured in point.
A point is 1/72 of an inch (0.0138)
Leading: the vertical space between lines of text
Line one
Line two
Leading

9. Kerning: the space between two characters
Adjusting the space between the characters is also called tracking

10. Character metrics: the general measurements of individual characters.

11. Cases Capital letters are called uppercase
Small letters are called lowercase
Text is generally easier to read with mixed uppercase and lowercase letters.

12. Issues when designing with text
Font compatibility: not all font is available on every operating system.
Choose regularly used fonts such as Arial, Times New Roman, Courier
If you want to use your own font, that font must be first installed.

13. Designing menu and icon
Menu: choose word with precise meaning
Icon/symbols : choose icon which has very few meaning for interpretation, or go for something which is globally understood.
Can be useful if language barrier is an issue
Consider using text label together with icons.

14. In some multimedia projects it may be required to create special characters. Using the font editing tools it is possible to create a special symbols and use it in the entire text.
Following is the list of software that can be used for editing and creating fonts:
Fontographer
Fontmonger
Cool 3D text

15. Images : Images whether represented analog or digital form, plays a vital role in a multimedia. It is expressed in the form of still picture, painting or a photograph taken through a digital camera.
Still images are the important element of a multimedia project or a web site.

16. Digital Image
A digital image is represented by a matrix of numeric values.
When I is a two-dimensional matrix, then I(r,c) is the intensity value at the position corresponding to row r and column c of the matrix.

17. Captured Image Format
The image format is specified by two main parameters: spatial resolution, which is specified as pixels x pixels (e.g. 640 x 480)and color encoding, which is specified by bits per pixel. Both parameter values depend on hardware and software for input/output of images.
Stored Image Format
When we store an image, we are storing a two-dimensional array of values, in which each value represents the data associated with a pixel in the image. For a bitmap, this value is a binary digit.

18. Bitmapped and Vector Graphics
Bitmaps: The computer stores information about the screen location and color value of each dot.
The refresh rate for bitmap is usually faster than for vector images
Used for Photo realistic images
Vector images: are composed of a large number of lines and circles, each reflecting a mathematical relationship.
Therefore, when refreshing a screen with a vector image, the computer must calculate all vectors again.
However, vector images are more precise and require less memory.
Vector’s are scalable with out losing resolution or quality

19. The Windows Paint accessory provides bitmap editing
Computer-aided design (CAD) programs have traditionally used vector-drawn object systems for creating the highly complex and geometric rendering needed by architects and engineers.

20. How Vector Drawing Works
Vector-drawn objects are described and drawn to the computer screen using a fraction of the memory space required to describe and store the same object in bitmap form.
A vector is a line that is described by the location of its two endpoints. A simple rectangle, for example, might be defined as follows:
RECT 0,0,200,200

21. Properties of Digitized images
Bit resolution or color resolution
1 bit (2 color)
2 bit (4 colors)
4 bit (16 colors)
8 bit (256 colors) Good
16 bit (65,536 colors) Excellent
24 bit (16.7 million) Photo-realistic
Device resolution or output resolution (dpi)
Refers to dpi of output device, a typical monitor is 72 dpi
Screen resolution (screen frequency)
Image resolution

22. Two important Notes
The higher the image resolution the greater the file size
Do not lower the resolution and later increase the resolution

23. Image File Formats GIF – 8 bits of color depth or 256 colors
Gif compresses drawings and cartoons that only have a few colors much better than jpeg
JPEG – 24 bits of color depth (millions of colors) is powerful but uses a lossy compression method.

24. Software used for creating images
Coreldraw
Paint
Autocad ….

25. Animation

26. Animation makes static presentations come alive
Animation makes static presentations come alive. It is visual change over time and can add great power to our multimedia projects.
Carefully planned, well-executed video clips can make a dramatic difference in a multimedia project.
Animation is created from drawn pictures
Video is created using real time visuals.

27. Principles of Animation
Animation is the rapid display of a sequence of images of 2-D artwork or model positions in order to create an illusion of movement. It is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in a number of ways.

28. The most common method of presenting animation is as a motion picture or video program.
The following shows a few cells or frames of a rotating logo.
When the images are progressively and rapidly changed, the arrow of the compass is perceived to be spinning.

30. Animation Techniques Cel Animation Computer Animation Kinematics
Morphing

31. The term cel derives from the clear celluloid sheets that were used for drawing
each frame, which have been replaced today by acetate or plastic.
Cel animation artwork begins with keyframes (the first and last frame of an action).

32. Example: when an animated figure of a man walks across the screen, he balances the weight of his entire body on one foot and then the other in a series of falls and recoveries, with the opposite foot and leg catching up to support the body.

33. The animation techniques made famous by Disney use a series of progressively different on each frame of movie film which plays at 24 frames per second.
A minute of animation may thus require as many as 1,440 separate frames.

34. Computer Animation
The same logic and procedural concepts as cel animation.
using layer, keyframe, and tweening techniques.
The primary difference between the animation software program is in how much must be drawn by the animator and how much is automatically generated by the software.

35. In 2D animation the animator creates an object and describes a path for the object to follow. The software takes over, actually creating the animation on the fly as the program is being viewed by your user.
In 3D animation the animator puts his effort in creating the models of individual and designing the characteristic of their shapes and surfaces.

36. Kinematics
It is the study of the movement and motion of structures that have joints, such as a walking man.
Inverse Kinematics is in high-end 3D programs, it is the process by which you link objects such as hands to arms and define their relationships and limits.
Once those relationships are set you can drag these parts around and let the computer calculate the result.

37. Morphing
Morphing is popular effect in which one image transforms into another.
Morphing application and other modeling tools that offer this effect can perform transition not only between still images but often between moving images as well.
The morphed images were built at a rate of 8 frames per second, with each transition taking a total of 4 seconds.

38. Following is the list of few Software used for computerized animation:
3D Studio Max
Flash
Animation Pro …

39. Animation File Formats
Some file formats are designed specifically to contain animations and can be ported among application and platforms with the proper translators.
Director *.dir, *.dcr
Animation Pro *.fli, *.flc
3D Studio Max *.max
Super Card and Director *.pics
CompuServe *.gif
Flash *.fla, *.swf

40. VIDEO

41. Using Video in Multimedia:
Carefully planned and high-quality video in which one can perceive text (title), image, animation, and sound all together can make an amazing difference in an interactive multimedia product. With the digital video technology we can use the power of video for multimedia and Web delivery.

42. Digital Video
Digital video has supplanted analog video as the method of choice for making video for multimedia use.
Motion is emulated by showing images in rapid succession
Visual persistence causes us to see an image for a split second after closing our eyes

43. Human eyes can process approximately 20 images per second before losing the ability to distinguish the transition of one image to another.
Motion picture industry standard uses 24 frames per second (fps) to create a continuous motion effect

44. A stick figure drawn in different positions can be brought to life by flipping the pages in rapid succession.

45. Digital Image and Video Formats
Digital images and videos could not be captured, stored, and disseminated without the existence of standard formats for compression
These formats provide the sets of rules, or protocols, required to compress and view images on display devices such as televisions, computer screens, cellular phones, and PDAs

46. Image Formats JPEG: Joint Photographic Experts Group
GIF: Graphics Interchange Format
PNG: Portable Network Graphics
BMP: Bitmap Picture
TIFF: Tagged Image File Format

47. Video Formats MPEG: Moving Pictures Experts Group
AVI: Audio Video Interleaved
WMV: Windows Media Video
MOV: Apple (Quicktime)

48. The video subsystem of a PC consists of two main components: ■ Monitor (or video display) The monitor can be a CRT or an LCD panel for desktop use, or a wide screen LCD TV, plasma display, or projector using LCD or DLP technology. ■ Video adapter (also called the video card or graphics adapter). On many recent low-cost desktop systems and virtually all portable systems, video might be built into the motherboard or included as part of this motherboard’s chipset.

49. Display Technologies CRT: Cathode Ray Tube LCD: Liquid Crystal Display
LED: Light Emitting Diode
Plasma Display

50. CRT Displays CRT Cathode ray tube emits three electron beams
The original display technology
Some computer monitors
Traditional television sets
Cathode ray tube emits three electron beams
Strength and direction of travel is controlled electromagnetically by a beam deflection mechanism
Follows a raster scan format

51. Components of a CRT Display

52. CRTs consist of a vacuum tube enclosed in glass.
One end of the tube contains an electron gun assembly that projects three electron beams, one each for the red, green, and blue phosphors used to create the colors you see on screen; the other end contains a screen with a phosphorous coating.
When heated, the electron gun emits a stream of high-speed electrons that are attracted to the other end of the tube. Along the way, a focus control and deflection coil steer the beam to a specific point on the phosphorous screen.
When struck by the beam, the phosphor glows. This light is what you see when you watch TV or look at your computer screen.

53. Three layers of phosphors are used: red, green, and blue
Three layers of phosphors are used: red, green, and blue. A metal plate called a shadow mask is used to align the electron beams; it has slots or holes that divide the red, green, and blue phosphors into groups of three (one of each color).
Various types of shadow masks affect picture quality, and the distance between each group of three (the dot pitch) affects picture sharpness.

54. Pixel/Dot Pitch

55. High voltage is used to produce the magnetism that controls the electron beams that create the picture displayed on the front of the CRT.
The electron beam moves very quickly, sweeping the screen from left to right in lines from top to bottom, in a pattern called a raster.
The horizontal scan rate refers to the speed at which the electron beam moves laterally across the screen.
During its sweep, the beam strikes the phosphor wherever an image should appear on screen. The beam also varies in intensity to produce different levels of brightness. Because the glow begins to fade almost immediately, the electron beam must continue to sweep the screen to maintain an image—a practice called redrawing or refreshing the screen.

56. Most current CRT displays have an ideal refresh rate of about 85 hertz (Hz), which means the screen is refreshed 85 times per second. Refresh rates that are too low cause the screen to flicker, contributing to eyestrain.
The higher the refresh rate, the better for your eyes.
Low-cost monitors often have flicker-free refresh rates available only at 640×480 and 800×600 resolutions; you should insist on high refresh rates at resolutions such as 1024×768 or higher.

57. It is important that the refresh rates expected by your monitor match those produced by your video card. If you have mismatched rates, you will not see an image and can actually damage your monitor.
Generally, video card refresh rates cover a higher range than most monitors. For this reason, the default refresh rate used by most video cards is relatively low (usually 60Hz) to avoid monitor damage. The refresh rate can be adjusted through the Windows display properties sheets.

58. Phosphor-based screens come in two styles: curved & flat
The traditional screen is curved both vertically and horizontally.

59. Curved CRT is inexpensive to produce, the curved surface can cause distortion and glare, especially when used in a brightly lit room.
Some vendors use antiglare treatments to reduce the reflectivity of the typical curved CRT surface.

60. LCD Displays LCD displays
Laptop computers
Digital camcorders
Gaming devices
Cellular phone
Use liquid crystal materials, whose properties can be varied by electrical signals.
An LCD system contains two glass plates that sandwich a liquid with tiny crystals filled in small cells, two polarizing filters on each side of the glass plates, a color filter, and backlighting for illumination from one face of the plates.

61. LCDs have low-glare, completely flat screens and low power requirements.
The color quality of an active-matrix LCD panel actually exceeds that of most CRT displays.
LCD screens usually are more limited in resolution than typical CRTs.

62. Components of an LCD Display

63. LED Displays LED displays
Present both still and time-varying digital images.
Large billboards, concert hall, and sports events
An array of tiny light emitting diodes, similar to small bulbs, which emit light of a certain color.

64. Components of an LED Display

65. Plasma Displays
Use an ionized gas that is trapped inside cells between two glass plates.
Each cell acts like a miniature fluorescent bulb.
The intensity of light emitted by each cell is controlled with electrical signals, and various phosphors that glow as red, green, and blue painted on one of the glass plates as light from the cells impinges on them.
The combination of red, green, and blue phosphors forms the color of each pixel in the display.

66. Technical Characteristics of Display Devices
Spatial resolution
Screen size
Pixel/dot pitch
Brightness resolution (bit depth)

67. Measurement of Screen Size

68. Projection Systems Film-based projectors LCD-based projectors
Digital light processing (DLP) based projectors

69. Originally, data projectors were intended for use in boardrooms and training facilities.
portable projectors are an increasingly popular alternative to large-screen TVs and plasma displays.
They can be used with Windows XP Media Center PCs and video players as well as their traditional partners, laptop and desktop computers.

70. An LCD projector works by separating white light into red, green, and blue wavelengths and directing each wavelength through a corresponding LCD panel.
Each LCD panel’s pixels are opened or closed according to the signals received from the signal source (computer, DVD, or video player) and are combined into a single RGB image that is projected onto the screen.

71. DLP projectors use a combination of a rapidly spinning color wheel and a microprocessor-controlled array of tiny mirrors known as a digital micromirror device (DMD).
Each mirror in a DMD corresponds to a pixel, and the mirrors reflect light toward or away from the projector optics.
The color wheel provides color data to complete the projected image.

72. Compared to LCD projectors, DLP projectors are more compact, are lighter, and cool down more quickly after use; however, they are more expensive.

73. The earliest DLP projectors used a simple three-color (RGB) wheel, as shown below. However, more recent models have used a four-segment (RGB and clear) or a six- segment (RGBRGB) wheel to improve picture quality.

74. Components of a DLP Projector

75. Broadcast Video Standards
Four broadcast and video standards and recording formats are commonly in use around the world:
NTSC, PAL, SECAM, and HDTV
Because these standards and formats are not easily interchangeable, it is important to know where your multimedia project will be used.

76. NTSC (National Television Standards Committee)
The United States, Japan, and many other countries use a system for broadcasting and displaying video that is based upon the specifications set forth by the 1952.
These standards define a method for encoding information into the electronic signal that ultimately creates a television picture.
As specified by the NTSC standard, a single frame of video is made up of 525 horizontal scan lines drawn onto the inside face of a phosphor-coated picture tube every 1/30th of a second by a fast-moving electron beam.

77. PAL
The Phase Alternate Line (PAL) system is used in the United Kingdom, Europe, Australia, and South Africa. PAL is an integrated method of adding color to a black-and-white television signal that paints 625 lines at a frame rate 25 frames per second.
SECAM
The Sequential Color and Memory (SECAM) system is used in France, Russia, and few other countries. Although SECAM is a 625-line, 50 Hz system, it differs greatly from both the NTSC and the PAL color systems in its basic technology and broadcast method.

78. Summary Digital video is based on the principle of motion emulation.
Because the human eye can distinguish at most 20 images per second, the frame rate standard used in the motion picture industry is at least 24 frames per second (fps), which creates the illusion of a perfect continuous-motion effect
Formats such as JPEG, GIF, BMP, PNG, TIFF, MPEG, AVI, WMV, and MOV provide the rules for structuring and compressing files that allow us to share and display images and video

79. Summary (continued)
The most common devices for displaying digital images are plasma displays, LCDs, CRT displays, and LED displays.
The design features that contribute to the quality of display devices are spatial resolution, screen size, pixel pitch, and brightness resolution (also called bit depth)

80. The end