by Iain Wilson
PNG is a good image format for web design in certain circumstances - a bit like gifs - good for images with blocks of same colour, no lossieness etc. They can also have a transparency attribute which can make them very useful. One thing to watch out for if you are still supporting IE6 is they way that browser handles PNG files.
Sometimes, IE6 will render the PNG file colours darker than they should be. If you're supplanting the image on top of a colour background, this can be disasterious. It's caused by IE6 incorrectly handling the gamma properties of the image, and that's how you can fix it - by removing the gamma spec from the image with a program such as TweakPNG.
Unfortunately, this works great when the PNG doesn't have transparency. If it does, removing the gamma spec improves things, but doesn't quite work on IE6.
The solution - advise your customers to upgrade their browser as per our recent article!comments powered by Disqus