On Wed, Jul 23, 2003 at 10:47:56AM +0200, Andrew Langdon-Davies wrote: | I know there's already been a lot of discussion on this subject and I've | read pages and pages, but I'm still unclear. I realise that just about all | recent browsers support PNGs. But, is it or is it not possible for IE (v. | 5, for example) to correctly display a PNG with a fully transparent | background so that anything behind it shows through? My PNGs are OK in | Mozilla, Netscape, Opera, Konqueror and Nautilus, but in IE they have a | rectangular white background that completely wrecks the effect. | TIA,
| Andrew
|

It is possible to achieve this using DirectX on IE under Windows. http://support.microsoft.com/default.aspx?scid=kb;en-us;Q294714

The reason that IE does not support alpha may be due to a design issue, rather than their reluctance to support PNG. You can achieve 1-bit transparency for example.

Mukund

Andrew Langdon-Davies wrote:

I know there's already been a lot of discussion on this subject and I've read pages and pages, but I'm still unclear. I realise that just about all recent browsers support PNGs. But, is it or is it not possible for IE (v. 5, for example) to correctly display a PNG with a fully transparent background so that anything behind it shows through? My PNGs are OK in

Yes. To do so, you need to make sure that your png is saved as an indexed image, rather than rgb (which png supports, but gif doesn't - this is why when you save as gif, you get a dialog asking you if it's OK to index the image sometimes).

To do this, go into the Image->Mode menu, and select Indexed as the mode of the image. Then choose a palette to use (automatic is usually OK), and save as png as you do normally.

The GIMP's png support is limited somewhat by its core support for indexed images - you can have one index entry completely transparent, but partial transparency (which is supported by png) is not supported for indexed images in the gimp.

Cheers, Dave.

On Wed, Jul 23, 2003 at 02:27:19PM +0200, David Neary wrote: | The GIMP's png support is limited somewhat by its core support | for indexed images - you can have one index entry completely | transparent, but partial transparency (which is supported by png) | is not supported for indexed images in the gimp.

Dave, does IE support the alpha channel with indexed PNG images? I would also like to know about the differences between IE/Win and IE/Mac w.r.t this feature.

Mukund

Mukund wrote:

On Wed, Jul 23, 2003 at 02:27:19PM +0200, David Neary wrote: | The GIMP's png support is limited somewhat by its core support | for indexed images - you can have one index entry completely | transparent, but partial transparency (which is supported by png) | is not supported for indexed images in the gimp.

Dave, does IE support the alpha channel with indexed PNG images? I would also like to know about the differences between IE/Win and IE/Mac w.r.t this feature.

No, that's a big bad for IE. They support RGB pngs, but not RGBA, and they support Indexed PNGs with GIF style transparency, but not multiple palette entries with different alpha values. I'm afraid I know nothing about IE/Mac. I have never been a mac user.

For example images to test IE against this, have a look at this enhancement request...
http://bugzilla.gnome.org/show_bug.cgi?id=86627

Cheers, Dave.

David Neary wrote:

Mukund wrote:

On Wed, Jul 23, 2003 at 02:27:19PM +0200, David Neary wrote: | The GIMP's png support is limited somewhat by its core support | for indexed images - you can have one index entry completely | transparent, but partial transparency (which is supported by png) | is not supported for indexed images in the gimp.

Dave, does IE support the alpha channel with indexed PNG images? I would also like to know about the differences between IE/Win and IE/Mac w.r.t this feature.

No, that's a big bad for IE. They support RGB pngs, but not RGBA, and they support Indexed PNGs with GIF style transparency, but not multiple palette entries with different alpha values. I'm afraid I know nothing about IE/Mac. I have never been a mac user.

For example images to test IE against this, have a look at this enhancement request...
http://bugzilla.gnome.org/show_bug.cgi?id=86627

Cheers, Dave.

internet explorer dropped support for mac, iirc. w3c bloggers dropped support for ie. i dropped support (temporarily) for netscape3.

if we drop support for broken browsers ie, any of them, and write things that should work, we could use png and show them how to add a gradient via css to a transparent background. some of the w3c cssers might already be doing this.

i am so sick of answering issues for other people. gimp follows standards. maybe gimp should start making them. no better app to grab the color to send to the background information in the css of any format.

anxious to never read about browser issues again in south lyon, carol

On Sat, 2003-07-26 at 18:46, Mukund wrote:

Dave, does IE support the alpha channel with indexed PNG images? I would also like to know about the differences between IE/Win and IE/Mac w.r.t this feature.

IE on the mac supported RGBA PNGs for as long as I remeber. It's a completely different browser.

cheers