Matthew Racki's Assignment

Multimedia is the presentation of information using text, graphics, animation, audio and video. It uses at least three different data types. Multimedia has the potential to provide a better experience than any other information medium. This eLearning product will teach you about multimedia and how you can use it.

What Is Multimedia?

An Introduction to Multimedia

The video below explains the definition and history of multimedia. Make sure you take notes.

What Year Was The Term Multimedia Coined?

  • 1966
  • 1993
  • 1999

What Does Multimedia Mean?

  • Multimedia is a program developed by Microsoft in 1966.
  • A type of website.
  • Multiple means of communication.

Types of Data and How They Can Be Manipulated

Text

Text is data in the form of letters, numbers and other special characters. Text is written using a word processor or within the authoring software. It is edited in many different ways, such as deleting, inserting, moving and copying. It is essentially raw text without any formatting. 

Graphics

Graphics are pictures such as drawings, paintings or photographs.Graphics are used to create interest and provide information. They can be stored, edited and transferred in similar ways to text. Graphics are created using graphics programs or captured using a scanner,digital camera or video camera. All graphics are displayed using tiny dots called pixels. A pixel (picture element) is the smallest part of the screen that can be controlled by the computer. The total number of pixels on the screen is called its resolution. There are two types of graphics: bit-mapped graphics and vector graphics.

Bit-mapped graphics (raster graphics) store and manipulate each pixel. They produce good quality images where shading and fine detail are needed. However, when resized bit-mapped graphics become ragged and suffer loss of resolution. Enlarging the graphic enlarges each pixel and creates a staircase pattern along a diagonal or curved line called jaggies. Bit-mapped graphics are created and edited using a painting program.

Vector graphics (object-oriented graphics) store pictures as a collection of objects such as shapes and lines. Each object is defined by its characteristics such as position, line width and pattern. These characteristics are stored as mathematical expressions and displayed on the screen as pixels. Vector graphics are created and edited using a drawing program. A hard copy of a vector graphic appears smoother than a bit-mapped graphic when enlarged.

Audio

Sound travels through the air in waves with a particular amplitude (volume) and wavelength (pitch or note). Audio is sound that has been digitized or represented in the form of digits. Audio is used to explain concepts, reinforce selections and for special effects. Audio signals from a computer are converted into analog sound waves for transmission through speakers. Sounds are edited in many different ways, such as deleting, changing the speed, adding an echo, overlaying (mixing) sound files and altering the quality of the sound file.

Animation

Animation is the apparent movement of an object. It is the result of a series of graphics or frames presented in rapid succession. Animations often direct the attention of the user to an area of the screen or an interesting feature. They are usually started automatically when a frame is viewed or by the user clicking a button. When creating an animation the user needs to consider the size of the graphic and the speed of the movement. Animation is created using path-based and cel-based animation. Cel-based animation creates an animation by using a sequence of individual still images, each displayed in a frame or cell. It is possible to have a fixed background, however, the shape of the animated objects and their position must be changed. Path-based animation creates an animation by displaying the movement of an animated object onto a fixed background in a particular sequence or path. The shape of the animated object remains the same.

Video

A video is made up of frames that contain individual images. When the video is played, the frames are displayed in sequence. The number of frames per second is the frame rate. Video has a frame rate ranging from 15 to 60 frames per second (fps).

Types of Files - Quiz

  • Text is...
    data in the form of letters, numbers and special characters.
  • Graphics are...
    pictures such as drawings, paintings or photographs.
  • Audio is...
    sound that has been digitized.
  • Animation is...
    a series of frames presented in rapid succession.
  • Video is...
    a series of images displayed in a sequence usually with audio.

File Sizes

Text

Text is digitized using a standard method of conversion such as ASCII.It works by assigning each character with a decimal number and converting this number into binary code. A scanner creates digital data from any printed page of text. However, unless instructed otherwise it will represent this text as an image. Optical character recognition (OCR) software converts text on paper into digital data that can be edited. The software matches the image from a scanner to the shapes of individual characters. Characters that are read are stored using ASCII codes and characters that cannot be read are usually indicated with a tilde (~).

Take Note Of The Following Formulas

Graphics

Graphics are digitized using a process called bit-mapping. Bit-mapping is the relationship between the graphic on the screen and the bits in memory. All graphics are made up of tiny dots called pixels. Each pixel in a graphic is assigned one or more bits. The number of bits per pixel is called the bit depth (or colour depth). At the simplest level,a graphic with a bit depth of one would have two colours. The 0 bit would be white and the 1 bit would be black. To determine the file size of a graphic in kilobytes we use the following formula:

Audio

Sound is digitized using a method called sampling. Sampling converts a sound wave to audio. It has three important characteristics called the sampling rate, bit resolution and the number of channels:• Sampling rate is the number of times a sample (slice) is taken from the sound wave. During a sample the amplitude of the wave is measured and converted to a number. The higher the sampling rate the better the sound but the larger the file size.

• Bit resolution (or sample size) is the number of bits per sample.The most common sampling sizes are 8-bit, 16-bit or 24-bit sound. The larger the bit resolution the better the quality sound.Voice is often produced using 8-bit sound. CD quality stereo sound requires at least 16-bit resolution and larger file sizes.

• Channels used by the sound. Mono uses one channel and stereo uses two channels (left and right) of sound. Stereo sound result sin better sound.

To determine the file size of audio in kilobytes we use the following formula:

Video

Video is made up of frames that contain individual images. To satisfactorily play a video we need to consider the speed at which the image can be shown. The speed of a video or animation is called the frame rate. It is measured by the frames per second (fps).The higher the frame rate the smoother the video or animation.

To calculate the file size of a video we need to first calculate the total number of frames. This is determined by multiplying the frame rate by the length of the video in seconds. Each frame will contain a graphic that has to be digitized. For this reason a formula to determine the file size of a graphic is required. The formula below calculates the file size of a video in kilobytes: