Difference between revisions of "AIM Class3"
(→Introduction to images on the web - including compression schemes) |
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| Line 32: | Line 32: | ||
When to use: an image that has a lot of detail (like a photograph). | When to use: an image that has a lot of detail (like a photograph). | ||
| − | Algorithm used: | + | Algorithm used: JPG |
Pros and Cons: | Pros and Cons: | ||
| + | #Lossy | ||
| + | #Works well with detailed images | ||
====GIF==== | ====GIF==== | ||
When to use: an image that has broad areas of color, an animated image, or an image with transparency (when using png is not desirable) | When to use: an image that has broad areas of color, an animated image, or an image with transparency (when using png is not desirable) | ||
| − | Algorithm used: | + | Algorithm used: LZW |
Pros and Cons: | Pros and Cons: | ||
| + | #Limited to 256 colors | ||
| + | #Compression works well with broad areas of color, but not with details | ||
| + | #Patent | ||
====PNG==== | ====PNG==== | ||
When to use: | When to use: | ||
| − | Algorithm used: | + | Algorithm used: PNG |
Pros and Cons: | Pros and Cons: | ||
| + | #Lossless | ||
| + | #Limited support in older browsers | ||
| + | #Potentially larger file size | ||
| + | #Transparency | ||
====SVG==== | ====SVG==== | ||
| Line 56: | Line 65: | ||
Pros and Cons: | Pros and Cons: | ||
| − | |||
===Size (visual and file size)=== | ===Size (visual and file size)=== | ||
Revision as of 02:02, 22 August 2006
Contents
Compliance and Verification of Documents
Review
1. Who creates the standards?
2. Are the standards mandatory for browser developers and for those who post content online?
Compliant XHTML/CSS
1. What do you need in order to make a document "verifiable"?
2. How can you "verify" a document?
Web Accessibility
1. What is web accessibility?
2. Why is web accessibility important?
3. How can you make a site more accessible?
Images on the Web and Compression Schemes
Formats
Main image formats for web publishing at this time: jpg, gif, png, svg (however the most accessible to older browsers are jpg and gif).
JPG
When to use: an image that has a lot of detail (like a photograph).
Algorithm used: JPG
Pros and Cons:
- Lossy
- Works well with detailed images
GIF
When to use: an image that has broad areas of color, an animated image, or an image with transparency (when using png is not desirable)
Algorithm used: LZW
Pros and Cons:
- Limited to 256 colors
- Compression works well with broad areas of color, but not with details
- Patent
PNG
When to use:
Algorithm used: PNG
Pros and Cons:
- Lossless
- Limited support in older browsers
- Potentially larger file size
- Transparency
SVG
When to use:
Algorithm used:
Pros and Cons:
Size (visual and file size)
Compression
Copyright
Fair Use, Copyright Issues, Creative Commons
Introduction to wrapping text
Introduction to the anchor tag - including pseudo classes
Links
W3c: http://www.w3.org/
Web Accessibility: http://www.w3.org/WAI/intro/accessibility.php
Overview of Accessibility: http://www.w3.org/WAI/References/QuickTips/Overview.php
Creative Commons: http://creativecommons.org/
Homework
Reading
ZEN: Chapter 1, pages 34-45
XHTML: Chapter 5, pages 83-98; Chapter 6, 104-115, Chapter 7, pages 117-132
