September 2001
Intermediate to advanced
640 pages
31h 42m
English
Content preview from Web Design in a Nutshell, 2nd EditionBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Chapter 21. PNG Format
The Portable Network Graphic format (PNG for short—pronounced “ping”) is a versatile and full-featured graphics file format that has been lurking in the shadows for several years. Despite some attractive features and the fact that it was created with web use specifically in mind, the PNG has been largely avoided by the web design community. This is primarily due to abysmal browser support and a lack of tools that can compress PNGs well enough to make them compete with GIFs.
The good news is that both browser and tool support has been gradually improving over the last several years. It remains to be seen, however, whether PNG will ever be permitted to live up to its potential.
The PNG Story
PNG was developed in January and February 1995 as an effort to find a non-proprietary alternative to GIF when Unisys threatened to enforce its patent on LZW compression and collect licensing fees from developers of GIF-supporting programs. This caused a flurry of outrage and activity on the Internet.
Days after the announcement, Thomas Boutell posted the first draft of the PNG specification to the comp.graphics newsgroup. A community of programmers then quickly cooperated in specifying and implementing an impressive list of features:
8-bit palette support (like GIF), support of 16-bit grayscale, and up to 48-bit truecolor (RGB) support
A lossless compression scheme and better compression than GIF for indexed color (palette) images
Two-dimensional progressive display that ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.