1 MULTIMEDIA TECHNOLOGY SMM 3001 MEDIA - TEXT

2 What is Text? the basic element of most multimedia the basic element of most multimedia consisting of words, sentences and paragraphs in the form of consisting of words, sentences and paragraphs in the form of Page titles Page titles Labels for pictures Labels for pictures Instructions for operating the applications Instructions for operating the applications used to convey information that have no visual or aural component used to convey information that have no visual or aural component e.g. feeling e.g. feeling

3 What is Text? (con’t) concerned with text from 2 view points: concerned with text from 2 view points: the way the text is presented the way the text is presented easy to read easy to read well-designed (font, colour and size) well-designed (font, colour and size) what lies behind the text what lies behind the text interactive link/hypertext/hot text interactive link/hypertext/hot text

4 Using Text in Multimedia Application choose fonts that are more readable choose fonts that are more readable READABLE (Century font)  (symbol font)

5 Using Text in Multimedia Application (con’t) keep the number of font typefaces to a minimum keep the number of font typefaces to a minimum too many fonts can be distracting too many fonts can be distracting This is to show that too many font typefaces will be certainly distracting This is to show that less font typefaces will be better

6 Using Text in Multimedia Application (con’t) text should not be too close to a picture or video text should not be too close to a picture or video difficult to read difficult to read consider colour, font and sizing when placing text over graphics consider colour, font and sizing when placing text over graphics Graduation ceremony

7 Using Text in Multimedia Application (con’t) vary size, boldness, style vary size, boldness, style e.g. use bold & larger font to get attention e.g. use bold & larger font to get attention ATTENTION !!!

8 Using Text in Multimedia Application (con’t) use white type on a black background or other reverse colours use white type on a black background or other reverse colours avoid colours which blend into each other avoid colours which blend into each other Can u read this?

9 Using Text in Multimedia Application (con’t) hypertext to other media facilitate information access on demand hypertext to other media facilitate information access on demand lower case letters are more legible than upper case letters lower case letters are more legible than upper case letters This is a text to show the different of lower case and upper case effect. Which is easier to read? THIS IS A TEXT TO SHOW THE DIFFERENT OF LOWER CASE AND UPPER CASE EFFECT. WHICH IS EASIER TO READ?

10 Text technology Text elements fall into few categories : Text elements fall into few categories : alphabets alphabets number number special character special character

11 Typeface graphic representations of the alphabet, numbers and special characters vary by type sizes and styles graphic representations of the alphabet, numbers and special characters vary by type sizes and styles graphical systems are able to create and use fonts due to a process called rasterization. graphical systems are able to create and use fonts due to a process called rasterization. rasterization occurs when the computer draws the font onto the display one pixel at a time. Fonts can appear jagged. Therefore, a technique called anti-aliasing is used to blend the font into the background by transitioning the colour from the font colour to the background colour. This technique minimizes the jagged edges making for a smoother overall appearance. rasterization occurs when the computer draws the font onto the display one pixel at a time. Fonts can appear jagged. Therefore, a technique called anti-aliasing is used to blend the font into the background by transitioning the colour from the font colour to the background colour. This technique minimizes the jagged edges making for a smoother overall appearance.

12 Typeface (con’t) Jaggies

13 Typeface (con’t) a computer must encode text as a series of numbers. a computer must encode text as a series of numbers. It must interpret processed numbers as text to be displayed on a screen, printer or other output device. It must interpret processed numbers as text to be displayed on a screen, printer or other output device.

14 Character character is defined as any symbol that requires one byte of storage character is defined as any symbol that requires one byte of storage this includes all the ASCII ad extended ASCII characters, including the space character. this includes all the ASCII ad extended ASCII characters, including the space character.

15 Encoded Text uses embedded codes to determine the appearance of the text uses embedded codes to determine the appearance of the text  The codes are separated with special characters e.g. line feeds or bracketed by symbols such as “ ”.  HTML is an example of text-based encoding  e.g. This is a title heading - the tags determine what formatting is used to present the text.

16 Encoded Text (con’t) Codes may be used to define Codes may be used to define typeface and size of font typeface and size of font font features e.g. bold. Italic, underlining and colour font features e.g. bold. Italic, underlining and colour paragraphs, indenting, bullets and alignment paragraphs, indenting, bullets and alignment page layout including header and footer, page numbering and background colour page layout including header and footer, page numbering and background colour

17 Data Compression Storing data in a format that requires less space than usual. Storing data in a format that requires less space than usual. Compressing data is the same as packing data. Compressing data is the same as packing data. Data compression is useful in communications especially because it enables devices to transmit the same amount of data in fewer bits. Data compression is useful in communications especially because it enables devices to transmit the same amount of data in fewer bits. Two technology - lossless and lossy compression Two technology - lossless and lossy compression

18 Data Compression - Lossless Codec - Codec - short for compressor/decompressor short for compressor/decompressor is any technology for compressing and decompressing data is any technology for compressing and decompressing data lossless compression refers to data compression techniques where no data is lost. lossless compression refers to data compression techniques where no data is lost. Example : The PKZIP compression technology is an example of lossless compression. It can reduce up to 50%. Example : The PKZIP compression technology is an example of lossless compression. It can reduce up to 50%.

19 Data Compression - Lossy For greater compression, lossy compression is applied For greater compression, lossy compression is applied lossy compression refers to data compression techniques in which some amount of data is lost. lossy compression refers to data compression techniques in which some amount of data is lost. Lossy compression technologies attempt to eliminate redundant or unnecessary information. Most video technologies such as MPEG use a lossy technique. Lossy compression technologies attempt to eliminate redundant or unnecessary information. Most video technologies such as MPEG use a lossy technique.

20 Data Compression - General View In general, data compression involves taking a stream of symbols and transforming them into codes. In general, data compression involves taking a stream of symbols and transforming them into codes. The resulting stream of codes will be smaller than the original symbols. The resulting stream of codes will be smaller than the original symbols. data compression is concerned with redundancy. Redundant information takes extra bit to encode and if we can get rid of that extra information, we will reduce the size data compression is concerned with redundancy. Redundant information takes extra bit to encode and if we can get rid of that extra information, we will reduce the size