Dogs See in Black and White But most don`t surf the Web

Dogs See in Black and White
But most don't surf the Web
Color, Graphics, Animated GIFs,
and Image Maps
Working with Color
• 16 Basic Color Names (3.05)
• Extended Color names (3.05)
• These 32 Color Names are interpreted
differently according to browser. Some
older browsers cannot use them. Like
"Paleturquoise" or "Seagreen"
• Use hexidecimal instead
RGB to Hexadecimal
• RGB Triplet (3.07)
• (0-9) represents 10 integers
• 10 = A, 11 = B, 12 = C, 13 = D, 14 = E,
15 =F
• Take each RGB number. (255, 255, 0) and
divide by 16.
• (16 x 15) + 15 = FF
– Number + Remainder
Use a Color Selection Resource
• For most of our cases, use a color
selection resource.
• Watch for dithering (check Web resource
page for chapter)
• I recommend using hexadecimals all the
time. (3.08 and back of book)
Color Schemes
• Viable Color Schemes
<body bgcolor = "color" text = "color" link
= "color" vlink = "color">
• W3 has deprecated the alink (the initial
color of a link when clicked)
Spot Color
• Use the font tag for Spot Color
<font color = "color">Yadda</font>
Font Face
• You can also change the FONT type
<font face = "Arial, Helvetica, San
Serif">yadda</a>
Background Images
• Inserting a background image
<body background = "image.gif">
<body bgcolor = "color" background =
"image.gif" text = "color" link = "color"
vlink = "color">
Care in Selecting an Image
• Make sure a user can still read the text.
• Do not use a large image file. (Less than
20 KB) More will increase load times.
• Background must look seamless, not tiled.
Image Formats
• GIF
– GIF87
– GIF89a
• interlacing, transparent colors, animation
• JPEG (JPG)
GIFs
• Interlaced (3.20)
• Transparent
• Animated (Like a cartoon)
– Animated GIFs are much larger than a regular
GIF. Be careful with file sizes. If you are trying
to make a motion picture with an animated
GIF, you might consider another format ;}
JPEGs (JPG)
• JPGs can be compressed and yield smaller
file sizes in some cases
• Primarily used when you want to have all
16.7 million colors in an image instead of
256
Compressing JPGs
• The more one compresses, the less the
image quality. (see 3.25)
• Make sure you always
– Save the original
– Do incremental saves
• Progressive JPEG
– Newer image format. Same as a transparent
GIF, but retains image resolution and colors
ALT
• The ALT Property needs to be used
– nice for the mouseover
– when images are turned off
– text browsers
– searches
Image Placement and Size
• Can be used for some great effects.
<img src = "image.gif" align = "alignment">
<img src = "image.gif" align = "alignment" vspace
= "value" hspace = "value">
<img src = "image.gif" height = "value" width =
"value">
Quicker Pages
• Reduce image file sizes
• Reduce number of colors in images
• Go for smallest file type
• Thumbnails
• Reuse images and backgrounds
Dithering
• Changing 16.7 million to 256
• Big difference
• Safety Palette of 211 colors that will
display without dithering
• Resource for Lab page has more
• Dithering still has its place, but it's not
used as much anymore because of
increased system power.
Image maps (3.37)
• What is an image map?
• Server-Side
• Client-Side
• Both have advantages and disadvantages
• We will work with a client-side map
Hotspots
• <br clear="left"> (Puts a comment above
the map.)
• Use one of the recommended programs to
define the hotspots. (I recommend
Fireworks.)
The HTML
<map name = "mapname">
<area shape = "shape" coords =
"coordinates" href = "url">
</map>
HTML (cont.)
Have to also call in the actual image, so. . .
<img src = "image.gif" usemap =
"#mapname">
# look familiar?
More on the AREA Tag
• Three properties
– Shape
• rect
• circle
• poly
– coords
– href
Even More. . .
• rect
<area shape=rect coords="x_left, y_upper,
x_right, y_lower" href="url">
• circle
<area shape=circle coords="x_center,
y_center, radius" href="url">
And yet some more. . .
• poly
<area shape=poly coords="x1, y1, y2, y3,
y4, . . ." href="url">
(Vertices of the polygon)
• Use the border="0" property in the <img>
tag
Example of an Image Map
• From the tutorial
http://homepages.wmich.edu/~rea/380/resources/SpaceExpo/Expo1999.h
tm
So. . . .
• Check out the Resources
• Check out the extra help on Lab 3
• Use Fireworks OR
– Get an image program
– Get Animagic (and see tutorial)
– Get an image map program
Take a Break
Requirements
Gathering
What do you need to know?
As a Web Developer You Need
to Know
• Who users are.
• What they want.
• What kind of computer experience they
have.
• What their computing environment is.
Who they are…
• Demographic information
– Age
– Gender
– Education
– Employment
– Others???
What they know…
• Domain Knowledge
– Expertise and Content levels
• UNIX for Geeks
• Kiosk for end-users
• User Computing Experience
– Programmer versus Casual Surfer
– Level of computing familiarity
• Metaphors
– Shopping cart
Computing Environment
• Web is not like fixed applications
– Variety of access points
– 600 x 800
– Multimedia
• Sparingly in most cases
• Plug-ins can be deadly
• Flash can fizzle
Content is King (or Queen)
• Content is important
– It's not your job to create
– It's your job to integrate
• What should be on the site?
• How should it be organized?
• What is needed…..(dramatic pause)
Gathering Requirements
What do users want?
Information Gathering
Techniques
• Surveys
• Interviews
• Focus Groups
Surveys
• Paper surveys
• Electronic surveys
• E-mail
– in-text
– attachments
• Web-based
– processing data
• Phone Surveys
Interviews
• Personal
– Come prepared
– Tape recorder
– Open versus Closed questions
• Phone
– Cold call
– Selected users
Focus Groups
• Room setting
– small versus large groups
– moderator
– synergy
• Electronic
– Group decision support systems
• Cost prohibitive
– Platform Issues
What to Use?
• Ask some questions
– Do users have e-mail addresses?
– Can you meet with them personally?
– Snail mail addresses only?
– Does a Website exist?
• More than likely use a combination of two
or more techniques.
Think About
• What techniques might you use?
• Team will be asked to provide information
gathering techniques, plans and tools in
reports.
– Initial: tools, techniques, any preliminary
results
– Final: tools, techniques, results
• Link to how the Website meets the needs