Characteristics

Characteristics Of Multimedia Systems

These Characteristics of an multimedia system are as follows:

- Text and numbers

- Text is a meaningful string of characters; 7 bits per character; A = 65

- Rules for using text

- Must be broken in paragraphs with clear headings

- Have correct spelling an grammar

- Have consistent formatting (size, font face, colour)

- Hyperlinks

- A link that transports the user to other parts of the system; allowing them to freely explore areas of interest

- Based on HTML codes (stored as text files)

- Anchor: transport user to another part of the same webpage

- Link: transport user to a new webpage

- Audio

- Music, speech and sound effects

- Must actually enhance presentation and not be large to reduce loading time

- Sampling converts sound waves into digital signals

- Sampling rate (number of sample of wave)

- Sampling size (number of bits used to represent each sample)

- Images

- Line drawings, photographs, icons, scanned documents

- More interesting than text; used for analysis

- When preparing images, need to consider: bitmap/vector; compression (lossy/lossless); bit depth; image resolution; screen resolution

- Image resolution: number of pixels used to display an image in a given space.

- Higher resolution images = better quality = use more pixels = require more storage

- Bitmap

- Composed of a matrix of pixels which can be controlled individually

- Bit depth is the number of bits per pixel (the higher bit depth, the more colours possible)

- Enlarging the image enlarges the pixels (creating a jagged effect and reducing resolution). This can be fixed by anti-aliasing (blend image to background).

- To calculate file size (kB) of an uncompressed bitmap image:

Horizontal pixels × Vertical pixels × Bit depth

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8 × 1024

- Vector

- Composed of primitives (basic shapes)

- Each line has mathematical coordinates for start and end points (but no points in between, which reduces file size)

- Not suitable for photographs (no shading)

- Can be resized without loss of quality

- Animation

- Creating the illusion of movement

- Cell based – a sequence of images where each cell is slightly different to the previous cell and when played gives the illusion of movement

- Path based – a character follows a drawn line across the background

- Video

- Combines image and sound data

- To represent video in binary, each frame is represented as a bitmap = large file sizes

- To calculate file size for video:

- Calculate total frames (frames/sec × number of seconds)

- Calculate size of each frame (Horizontal pixels × Vertical pixels × Bit depth)

- Calculate total file size (frames × size of each frame = bits)

- Buffering prevents delay when playing videos

- Need to consider: frame resolution, frame rate, bit depth and bit rate

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Table for reference to the above Media types

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Differences between print and multimedia:

- Print has higher resolution than multimedia.

- Print is static = minimal interactivity. Multimedia is dynamic = designed for interactivity so user controls content (hypermedia, keyword searches, navigation buttons, site map, realistic displays)

- Print is harder and more expensive to distribute (heavy). Multimedia is easier to distribute (stored on lightweight devices; cheaply transmitted via internet)

- Distribution for print requires printing presses, ink, paper and willing publisher. Multimedia requires hardware, software and basic skills.

- Updates to print are not immediate (cannot be edited without reprinting). Updates to multimedia are immediate (e.g. online news).

- Print tends to be more trusted (books are checked by third parties)

Table for reference to the difference of media

Characteristics of Multimedia: Video

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Environmental Factors of Multimedia designs

One of the positive factors of introducing this system to the general public across all schools would be the efficiency of the system at finding the information of what you need to succeed in these specific categories giving students a very easily accessible way to view this information that gives them raw text book definitions which is exactly what students are looking for. But one negative that comes with this is its too specific in the information that it gives which will lead students to stray away from the text book and to not read all of it which poses a really by problem if students stop reading the text book that has all the information in it for only some specific information about the systems. A solution to this problem would be to number what pages certain information is from on the website therefore giving the students a very easy way to find the full information that they need to get from the book not only just some specific things about the multimedia system.

Another positive factor is that students do not need to actually buy the associated text book that you would find this information in saving students a lot of money but also time that they would have spent looking for this information either countlessly scrolling through websites to find it or getting stuck on the text book that they had to buy. A negative is that the text books could become useless if this multimedia system covers too much of what it was designed to do therefore it could even start to break copyright laws or cause the book makers to lose a lot of money on what they were owed for writing the books. A solution to this problem would be to include this multimedia system as a sort of side reference website for when you purchase a copy of the book therefore providing a good information point but at the same time saving the creators of the book.

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