Transparency

[mikee]

Hi, does anyone know a way of making any white in an image transparent? I've heard of the Opacity thing but i'm not sure if that's what i'm looking for please help.
Mike.

[grahamstewart]

Use a GIF image.

That format supports transparency.
Any decent art package should support it.

[brdwlsh]

yes, save it as a gif.

if possible, use a matte as well--the same color as what will appear behind the image. this will prevent the image from having jagged edges.

[mikee]

Thanx!

[mikee]

Does anyone know of a FREE graphics editor that supports transparency 'cos none of the software i have does(Pixia).

[grahamstewart]

You can get a free trial of Paint Shop Pro from the Jasc Software page (www.jasc.com). But if you're getting into web development seriously then you'll probably need a full version of a decent art package.

[isitreal]

You can also make it a .png, people seem to forget about .png even though it's a techncically superior format to gif

[mikee]

Thanks for all ur help and i will consider purchasing some decent graphics software but for now does anybody know of anybody freeware that supports transparency, it doesn't matter if it is krap as long as it supports transparency.

[isitreal]

Yes, this one will do it, it's the highest rated free multimedia app out there as far as I know:
[irfanview.com...]

Download it, check the help index for transparency, it will tell you how to do it.

[hyperbole]

Go to mindworkshop (you can find them at google by searching for alchemy-mindworks)

They have two very good products: GIF Construction Set, and PNG Construction Set. They can be used to create GIF and PNG images with transparency.

[mikee]

Great, thanx for your help everyone!

[mikee]

Hello, sorry to bother u (yet again) but with the transparency thing i still get a square box just a rectangle with rounded corners layered on the top. Is there any way round this? If u had no idea what i am going on about goto: [members.lycos.co.uk...]

[mikee]

Have i used a krap method in my code or what?

[tolachi]

You might try using the gimp. It is pretty full featured, runs on linux and windows, and is free. I've done a lot of stuff like what you are talking about with it. I know some photopraphers use it as well.

[gimp.org...]

You also might have better luck getting online support via its user mailing lists.

[mikee]

Thanx for that and i will but i think i've sorted it now if i just change the colour that is made transparent different then it should work.

[mattr555]

To the guy who mentioned transparent PNGs. They are not currently supported by IE. PNGs Yes, transparent PNGs NO.

[grahamstewart]

Actually you are wrong there.

The simple on/off transparency in PNG-8 IS supported in IE.

What IE does not support is the alpha-channel variable transparencies of PNG-24.

So basically you can use PNGs for the same purposes as GIFs in IE.
You just can't use the funky ability to say 'this pixel is red and 50% transparent'.

(Note: as per usual, all other modern browsers support png-24 properly - just not IE)

[Leosghost]

Whilst agreeing with grahamstewart....I think that the main reason against use of png will always be its incredibly large file sizes compared with gif or jpeg ..yes it may be "lossless" but when you see the file size before and after basically that claim is only because it compresses no better than a good jpeg algo at only one incremental "squash" ....
... anything can claim to be lossless if it doesnt actually compress worth talking about!
The day we are all on adsl or broadband png might be a valid format but for now ....if you want to ( or have no choice but to ) use 56k its irrelevant ..and BTW it is lossy anyway ..just not much ..

My 2c FWIW

[Mobull]

PNG 24 bits only work within IE 5.x and up IF you have installed DirectX and if you use Microsoft's filters.

Problem with this is however, if you have a link on top of the PNG image that uses this filter, the link won't work anymore :(

for ms reference check this:
hxxp://msdn.microsoft.com/library/default.asp?url=/workshop/author/filter/reference/reference.asp

[grahamstewart]

incredibly large file sizes compared with gif or jpeg

erm.. I find a PNG is usually considerably smaller than the same pic as a GIF (which is also lossless by the way).

Fancy a test? Sticky me the address of an optimised GIF and I'll do it as a PNG and see what file size I get. :)

[Farix]

I think that the main reason against use of png will always be its incredibly large file sizes compared with gif or jpeg

If you are comparing PNG-24 with GIF then, you are correct most of the time. But when you compare PNG-8 to GIF, over 90% of the time it is the PNG file that is smaller.

There are few excuses to use PNG-8 over GIF today. All browsers, including IE, supports PNG-8. The only advantages GIF has over PNG-8 are with animation and extremely small and simple images--no more then a few pixels at a color depth of 3-bits or less.

[Jared_NZ]

I wouldn't say 90% of the time PNG is smaller, more likely for me 30% of the time it is.

Works great with text'd images, but it always depending on what you're designing. Which would never be the same as we all design something different and trying compare something that is different all the time is pointless. As it will always be different.

[grahamstewart]

"PNG also compresses better than GIF in almost every case (5% to 25% in typical cases)."
- [w3.org...]

The problem is that many people use Photoshop and the PNG output from that isn't very optimal. Have a look for 'pngcrush' (or pnggauntlet if you prefer gui tools) a useful addition to the toolkit.

[Farix]

I wouldn't say 90% of the time PNG is smaller, more likely for me 30% of the time it is.

I've done plenty of GIF to PNG-8 conventions along with a small handful I've created on my own. Out of the the hundereds of images I've worked with, I've only encountered roughly four cases were the GIF was smaller then the PNG. So my 90% is being very generous toward GIF.