CISB 11 - Computer Information Systems

bewgrosseteteSoftware and s/w Development

Dec 13, 2013 (3 years and 5 months ago)

62 views



CISB 11
-

Computer Information Systems

Chapter Study Notes


Chapter 10
-

Multimedia and the Web

Multimedia refers to combining multiple types of media, such as text,
image
s, video, animation,
and sound

onto web pages
. One of the biggest developments

of the Internet over the last few
years has been the growth of multimedia

applications.


Common Web
-
based multimedia applications include:



Information delivery (news, companies, organizations)



E
-
Commerce (marketing and transactions)



Entertainment (music,
video, games)



Web
-
based training/education (companies and
schools
)


The most common multimedia elements are:



Text: characters, numbers, and punctuation displayed in a variety of sizes (10
-
point, 12
-
point, 14
-
point), typefaces (Times New Roman, Arial, Couri
er New) and colors.



Image
s: photographs, drawings, charts, clip
-
art, and other non
-
moving visual images.
The two most common image formats for Web pages are GIF and JPEG. GIF can
display up to 256 colors and is most suitable for non
-
photographic images.
JPEG can
display up to 16 million colors and is the standard format for Web page photographs.

o

The file size and format of an image can be changed using image editing
software.

o

A thumbnail image is a small version of an image that is linked to a
correspondi
ng full
-
size image. Thumbnails are used to save loading time.



Animation: refers to graphical images that are displayed rapidly one after another to
simulate movement. Java Applets
,

animated GIFs
, or
animation programs such as
Silverlight or Flash

are fre
quently used to add animation to a Web site.



Audio: includes music, spoken voice, and sound effects. Most audio files require either a
browser plug
-
in or player program such as
Apple
QuickTime Player, Windows Media
Player, or RealPlayer. Streaming audio
is when a small portion of the audio file is
downloaded and buffered (placed in memory or temporarily stored on the hard drive).
This allows the audio file to begin playing while the remainder of the file is still
downloading. Streaming audio is recomme
nded for large audio and video files.
Common audio formats are wav, mp3, and
aiff



Video: a continuous stream of visual information that is broken into separate images
(frames) when the video is recorded. There are many video formats (avi, mp2,
mp4, and
mov

a
re a few).


Designing Web Pages


When designing a Web site, it is important to keep two basic principles in mind:



Users like interesting and exciting Web sites (use of multimedia and a frequently changing


home page)



Users have little patience with slow
-
loading pages or
hard to use
applications
.


Because of the many different browsers, media plug
-
ins, screen sizes, and bandwidth capabilities
available to internet users web developers should attempt to develop web pages

that can be easily
viewed by many different co
mputer configurations. Factors

to consider include:



Eliminating features that require a specific browser



Try not to use media that require little used plug
-
ins



Keep images intended for PCs to 710 pixels wide
and 4
2
0 pixels high.



Limit

audio, video, and animation files
that require high
-
speed bandwidth

as not every
Internet user has a high
-
speed connection.



Before developing a Web site, you should ask two questions. The answers to these two questions
will
greatly determine both your Web site’s content and appearance:



What is the objective of the Web site? (influences Web page content)



Who is the intended audience? (influences Web page appearance)


Web developers typically design both the Web site and the
Web pages before creating the Web
files (see pg. 4
11
).



Web sites are designed using Web flowcharts



Web pages are designed using page layouts


Web sites should also be designed so that they are accessible by people using assistive
technology
--
hardware and
software specially designed for use by people with physical
disabilities. Techniques include:



Providing alternative text for all images



Having a high degree of color contrast between text and the background



Have descriptive hyperlinks (don’t just state
“click here”)


Web Development Languages:


Hypertext Markup Language (HTML) is the primary language used to create Web pages.

HTML uses tags to indicate where Web page content will appear and how it will appear
.



Pg 415 lists the purposes of some common HTM
L tags.



Pg 416 provides an example of HTML code and its resulting Web page.



Many tags also have a closing tag

which is a forward slash in front of the tag
abbreviation that indicates the end of that tag property.



Extensible Markup Language (XML) is a se
t of rules for exchanging data over the Web. XML
focuses on identifying the data itself

not the format of the data. There are no standard XML
tags

each organization can create their own customized XML tags.


XHTML is a newer version of HTML that supports

XML. With XHTML, XML controls the
content displayed, and XHTML controls the appearance and format of the Web page. XHTML
tags are very similar to HTML tags (pg 4
17
).


Wireless Markup Language (WML) is a language used to create Web pages to be displaye
d on
WAP
-
enabled devices, such as smart phones.


Scripting languages enable Web authors to create Web pages with dynamic content (such as user
interaction and database connectivity)

by putting programming code, called scripts, within the
web page code
.
Fo
ur

of the most popular scripting languages are JavaScript, VBScript and
PERL.



JavaScript
is used to add interactive content to Web pages, such as pop
-
up windows or
other objects that are displayed when the mouse points to an object, button, or menu item
on

a Web page.



VBScript, developed by Microsoft, is used for the same purposes as JavaScript. VBScript
code is very similar to the Visual Basic.NET programming language. A primary
disadvantage of VBScript is that it is
not

compatible with
some

browser
s
.



Perl is one of the most popular languages for writing CGI scripts

which are often used
to process data entered into Web pages forms that are linked to databases.



AJAX uses a combination of HTML, JavaScript, and XML to create faster and more
efficient inter
active web applications.


Web
-
authoring software simplifies Web development by enabling individuals to create Web
pages without writing HTML code. Most Web
-
authoring SW also has the capability to include
multimedia elements such as animations, audio cli
ps, and video clips. Two popular Web
authoring programs are Adobe Dreamweaver and Microsoft Expression Web. These programs
also enable the user to upload the completed Web site onto a Web server.



Review


Define multimedia as it relates to Web site des
ign.


Describe the types of multimedia elements that can be viewed and/or heard over the Internet.


What two questions should be asked before developing a Web site?


What factors should be considered when creating a Web site
.


What is a Web flowchart?


W
hat is a Web page layout?


Define the following terms:



HTML



XML



XHTML



WML



JavaScript



VBScript



PERL



AJAX



Web
-
authoring software


Name two popular web
-
authoring software products.





The chapter notes discuss the most important topics from the textbook.
Most of the quiz
and test questions will assess your understanding of the topics discussed in the chapter
notes. You are expected to know the information provided in the textbook abou
t these

topics

even if I do not discuss them during classroom lecture ti
me.