CSS PNG圆角效果

CSS PNG圆角效果（转）

PNG Overlay

17 January 2007 › 28 comments

PNG Overlay: Example | Download (44 KB)

Have you ever run into the problem of creating a site with pictures given by the client, only to find later after they update their photography the original look and feel is not retained? For instance, you might add a drop-shadow, rounded corners (maybe both) or some other graphical effects applied to the images. This is all well and good, but what about the webmaster or journalist who follows after you – Will he or she be able to keep the look consistent?

In order to help remedy this potential problem, here is a solution that I came up with. Basically, it involves creating a transparent PNG overlay which can be used as a mask / frame around regular JPEG or GIF. This way, a typical CMS installation can be configured so users can upload photos without having to worry about using any graphics program to apply filters. Even if you are already a whiz with graphics, it will help save you time.

The nice thing about this method is that you are just applying an absolutely positioned <div> with a PNG backround over the top of a regular image, so you still get the benefits of a relevant alt attribute / value pair, as well as printing images because they are technically in the foreground as far as the browser is concerned. It will even work in IE6, with the proprietary Microsoft alpha style filter applied. IE7 will handle the transparency natively.

I am not going to go in depth and explain how to make transparent overlays, because there are already plenty of Photoshop tutorials out there. For a good explanation of how to achieve this effect in Fireworks, check out the article at solarDreamStudios. I hope this demo inspires ideas and makes life easier.

还有一个css圆角效果： http://www.htmldog.com/examples/images3_3.html