What is Multimedia/Digital Media

• Multimedia involves the use and integration of media (for example, text, images and graphic elements, animation, sound and music, and video) to create digital products that are available online or offline..

Examples of Multimedia product

An online encyclopedia can be an example of multimedia product

Other Examples include;

• Online or digital Games
• Interactive Websites
• Online Movies on DVDs etc

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http://www.britannica.com/

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Components of Multimedia �

A multimedia system should have most of the following combinations of media

• Texts
• Images
• Videos
• Audio
• Music
• Animations
• Simulations

We will examine each of the above in detail

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TEXTS

We use an interactive website as our product.

All websites must have text in them.

Texts in a Computer

01 Bits Byte Character Word

The word “Welcome” is made up of 7 bytes which is 56 bits

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Try to convert text to binary in

http://nickciske.com/tools/binary.php

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Texts Formats

The common text formats are

.TXT,

.RTF,

.LOG,

.DOCX. �Others include .dotz, .dsc,.eml

Why is it important to know the text format of a file?

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Hypertext and Hypermedia

Hypertext is a non-linear text that connects various elements (nodes, pages) through links. “Hypertext is text with links, to other texts or pages”

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Hypermedia is an extension to hypertext that but this supports linking graphics, sound, and video elements in addition to text elements. The World Wide Web is a partial hypermedia

Activity 1

If a page in a digital book contains 240 words per page and each word averaging 6 letters, how many pages can

1. A 700MB disk hold?

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b) A 2 GB Flash disk hold?

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Images

Most website have images on them.

How are images captured for computer processing?

• Using digital cameras
• Scanning
• Drawing using software

http://www.dl-c.com/basics.pdf

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Computer Images

• Digitization is the process of converting information into a digital format.
• Computer images are composed of Pixels (short for picture elements).
• Each pixel represents the color (or gray level for black and white photos) at a single point in the image.
• So a pixel is like a tiny dot of a particular color.
• A digital image is a rectangular array of pixels sometimes called a bitmap

• The density of pixels in an image is referred to as its resolution. The higher the resolution, the more information the image contains.
• Color depth is the number of bits devoted to each pixel.
• There are two quite different techniques for creating, storing and processing computer images: bitmap graphics and vector graphics.

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Bitmap Graphics

• A bitmap image is a computer file used to store a picture. It consists of tiny blocks called pixels.
• Images taken with a digital camera, scanned images and most of web images are bitmapped images.
• Bitmap formats include: jpg, bmp, gif, png and tiff.

Bitmap file formats

• BMP: an outdated and limited file format
• EPS: a flexible file format that can contain both bitmap and vector data. It is gradually being replaced by PDF.
• GIF: mainly used for internet graphics
• JPEG: or rather the JFIF file format, which is mainly used for internet graphics
• PDF: Portable Document file format that can contain just about any type of data including complete pages, it is widely used to exchange just images
• PICT: file format that can contain both bitmap and vector data but that is mainly used on Macintosh computers and is not very suitable for prepress.
• PSD: the native file format of Adobe Photoshop (which can also contain vector data such as clipping paths)
• Tag Image File Format (TIFF) a popular and versatile bitmap file format internet graphics

Disadvantages of Bitmapped images

• Does not tend to resize very well.
• It is not easy to enlarge the image without the image becoming pixilated.
• Bitmap file is a large file size.
• Such large a file can take a long time to load, send, or receive. To combat this, different compressed file formats can be used.
• many times compressing a bitmap file can result in artifacts, areas of blurry or incorrect color in the image.

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JPEG (.jpg or .jpeg) and CompuServe Graphics Interface (.gif) are both compressed bitmap file types.

The JPEG file type may work on a very large and detailed file, such as a photograph, but a GIF may be best suited for graphics, text, or animations.

Vector Graphics

• Vector graphics are images that are completely described using mathematical formulas.
• Vector graphics image is stored in memory and processed as lines rather than a series of dots,

Vector Graphics File Formats

• EPS: the most popular file format to exchange vector drawings even though PDF is quickly gaining ground.
• PDF: Portable Document file format that can contain just about any type of data including complete pages.
• PSD: the native file format of Adobe Photoshop.
• AI: the native file format of Adobe Illustrator.

Others include; cdr, dxf, emf, svg and swf.

Vector Graphics Merits

• They generally have smaller file size than bitmaps
• They are so easy resizing.
• You do not easily loss in quality of image while resizing. Fonts are a good example of vector graphics no matter how you enlarge your font, it will look very sharp.
• Converting from a vector to a bitmap is generally much easier than the opposite. To convert from bitmap to vector, you need something like tracing. It is almost like; drawing over the bitmap to get a vector. E.g. accomplish this task like in Adobe Illustrator CS2
• Some file formats could have both raster (bitmap) and vector like pdf, pgm and emps.

Activity

Convert Bitmapped image to vector graphic image using

http://vectormagic.com/home

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Converting Vector to Bitmapped graphics

Use http://www.online-utility.org/image_converter.jsp?outputType=JPEG

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Google Vector images and convert them to Bitmapped images and compare their size

Photo editing Techniques

• What are the different types of photo editing software?

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• List down the different photo editing techniques

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• Photo editing allows photographs to be transformed into new fake images as shown below;.

http://fx.worth1000.com

Activity

Source: [http://fx.worth1000.com/entries/599273/loose-ball]

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Create a fake image using any software similar to the above

Photo editing techniques

• Superimposition idea: e.g. two or more original photos to appear as one and create a fictitious situation
• Editing / alteration of existing image: e.g. add/erase information.
• Morphing- Transforming an image into something else
• Photo masking:  Photo masking is one of the most necessary pre-production work of graphic designing and used for background removal of any complex image.
• Photo stitching: Panorama stitching is the process of combining multiple photographic images with overlapping fields

Audio files

• An audio file is a record of captured sound that can be played back.
• Sound is a sequence of naturally analog signals that are converted to digital Sound is a sequence of naturally analog signals that are converted to digital signals by the audio card, using a microchip called an analog-to-digital converter (ADC).
• When sound is played, the digital signals are sent to the speakers where they are converted back to analog signals that generate varied sound.

• Audio files are usually compressed for storage or faster transmission.
• Audio files can be sent in short stand-alone segments - for example, as files in the Wave file format.
• In order for users to receive sound in real-time for a multimedia effect, listening to music, or in order to take part in an audio or video conference, sound must be delivered as streaming sound.
• More advanced audio cards support wavetable, or precaptured tables of sound. The most popular audio file format today is MP4 (MPEG-1 Audio Layer-4).

Audio file Formats

Mp3

• Most popular audio file format
• The MP3 format is a compression system for music.
• The MP3 format helps reduce the number of bytes in a song without hurting the quality of the song's sound.
• With MP3, a 32 megabyte song on a CD compresses down to 3 megabytes or so.
• This lets you download a song in minutes rather than hours, and it lets you store hundreds of songs on your computer's hard disk without taking up that much space.
• MP3 file format will not sound like the original file

MP3

• The file is easily played with RealAudio Quicktime, and the new Windows Media Player,
• Many others also support the format.
• MPEG is the acronym for Moving Picture Experts Group. It is an encoded format for small efficient files true to the instruments and studio conditions that produced the sound. MPEG supports both analog and digital recording formats.

WAV file format

• The Microsoft .WAV file format is a technique for storing analog audio data in a digital format.
• A *.WAV file is a digital recording of the sounds made by any instrument or human voice. It basically cannot be modified.
• When a PC plays back a WAV file, it converts numbers in the file into audio signals for the PC's speakers.
• A complete tune recorded in .WAV format is always very large.

AU file format

• AU is short for AUdio, a common digital sound file format used on Unix machines and the standard audio file format for the Java programming language.
• The file has a very simple structure: the file header specifies the basic parameters of the sound - sampling rate, sample size, number of channels and type of encoding - followed by the sound data.
• AU files are relatively low quality and are not highly compressed.

MIDI File Format

• MIDI Stands for Musical Instrument Digital Interface, and is one of the oldest format.
• These files are tiny, and make quick downloads. Most multimedia audio players will support the MIDI format.
• MIDI information tells a synthesizer when to start and stop playing a specific note, and may include the volume and modulation of the note. The synthesizer comprises your PC's sound card and device driver.
• Many tunes are available in MIDI format, and you can listen to these tunes using the free players that are

• A*.MIDI file contains what the composer (or the person who played a tune) did at his/her music keyboard. It keeps track of which note (key) was pressed, when it was pressed, for how long, and at what pressure.
• Playing back a MIDI file requires a device (sound card) that can generate the sounds of common instruments (for example, Piano, Violin, Drum) on its own.
• The note data is sent to the device, which then generates the sounds that were intended (or sometimes not intended).
• A MIDI file is comparatively very small and can be edited (including changing the instruments altogether).
• The quality of the sound is dependent upon the quality of the synthesizer on a PC's sound card.
• Because MIDI files are synthesized audio and not sampled audio, they play back in audio quality only as good as your PC's sound card.
• MIDI files sound different on different computers.

AVI file format

• The AVI (Audio Video Interleave) format was developed by Microsoft.
• The AVI format is supported by all computers running Windows, and by all the most popular web browsers.
• It is a very common format on the Internet, but not always possible to play on non-Windows computers.

Podcasts

• Podcasts are audio files that are automatically delivered directly to your desktop computer, and can be transferred to your iPod or other MP3 player.

Digital Video

• Digital video is just a digital representation of the analogue video signal.
• A Video file is collection of images, audio and other data.
• Video capture is the process of converting an analog video to digital video

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Video File Formats

Write brief notes on the following video file formats

• AVI ( Audio Video Interleaved )
• MOV
• ASF ( Advanced Streaming Format )
• RM ( RealMedia )
• MP4 ( MPEG-4 )
• SWF, SWV ( Shockwave Flash )
• NSV ( NullSoft Video )

Video Editing software

Video editing Enables people to edit videos on a computer. Example include

• VideoPad Video Editor
• CyberLink PowerDirector
• Windows Movie Maker (Windows XP)
• PhotoStage Slideshow Producer Professional

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Video software Techniques

• Morphing
• Digital video fingerprinting .

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Vidcasts

Vidcasts are short for video podcasts. This

Describes the online delivery videos on demand, Similarly to podcasts.

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Special Effects

The illusions used in films, television and

Theatres Used to simulate the imagined events in a story are called Special effects. These Effects can either be done on the computer or mechanically

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Social And Ethical Issues