transcluent background

Hello, How can I apply a 50% opacity to a background? :)

Creat your graphic and save it in Gif will works. Jpeg doesn't.

Hope this helps.

I mean from a gif and the background of a page

What's behind the background?

Originally posted by light_wt
Creat your graphic and save it in Gif will works. Jpeg doesn't.

Hope this helps.
I thought .gif only support fully transparent attribut...am I wrong?
of so, how do I "save" it?

yeah, I tried a 50% opacity. it appeared full. How can I make it where it actually supports opacity?

Try PNG.

I've had problems making PNGs transparent, but have heard others say it's possible...

You can currently expect op7, moz and iem to fully support alpha transparency images (PNGs). You can also get it in iew, but with some trickery. You can't get repeating backgrounds, for one. KDE said previously that they wouldn't add support for alpha transparency in konq because of the performance impact they would get from them, but that was a long time ago. Maybe it's changed. If not, expect Apple to add it in saf and give back to the community.

Mozilla also added support for CSS3-Color rgba and hsla through the extension values -moz-rgba() and -moz-hsla() not too long ago.


Also note that alpha transparency on anything that's not static has a terrible impact on performance. Have a few alpha transparency images bounce against the sides ot the browser window for awhile, and moz will run the speed of a snail who's had one too many trucks running it over.

on roys site his image things he has some opacity. Maybe I could do something like that, take a screenshot then use that so it appears to be transparent?

@liorean, thx for the info. but it's just the theory...and on practice how do I do it? what software I can use? how about windows support? IE?
does Adobe Photoshop 7 can do it?

Adobe Photoshop can do it, but it's not really that good at it. The GIMP know it pretty well. Macromedia Fireworks is excellent at it.

As I said, iew doesn't support it without some trickery.

Originally posted by liorean
As I said, iew doesn't support it without some trickery. [/B]
iew = IE eh? :rolleyes:
thx!
but, what kind of trickery? if u know any source where we should look for it, would u provide it? thx.:thumbsup:

iew = Internet Explorer for Windows. In this case 5.5 or above. Internet Explorer for Macintosh is an entirely different beast. In most cases, you should consider them entirely separate browsers.

The best source is <http://webfx.eae.net/dhtml/pngbehavior/pngbehavior.html>.

What are some good PNG programs? I use Bmp2Png and PngCrush. With those, I made a 10 kb bmp file (200x24, 56 colors) down to about 100 bytes. Gif format could not make it less than 1 kb. Though the conversion programs I used don't seem to do any transparency effects, it did say something about it. But I don't know how to use it. Both are command-line DOS programs btw.

pngcrush, pngquant (http://liorean.f2o.org/pngquant.zip) (this does alpha) and the GIMP (unless you want to pay for the graphics editor) are the tools to use. Photoshop makes really large and unwieldy pngs - I've even seen it produce pngs that are larger than the uncompressed png was.
Macromedia Fireworks is really, really good for pngs. pngcrush can seldom reduce file sizes that very much when Fireworks is the source.

Thanks, I'll give it a try. Though on some occassions, gif has been better than png. But only on very small images. Try the images on http://XFox_Prower.tripod.com/games/js/slide/miles and you'll see what I mean. But the images at http://XFox_Prower.tripod.com where the background effects behind the emeralds are are only about 100 bytes each. Select properties to see!