Hi Neil,

Quoting Neil Watson :

I know that IE has issues with transparent PNG files. I have noticed that it is
somewhat random. Some files display correctly while others don't. Is there some type of method or work around that will create a transparent PNG file that IE will display correctly?

All PNGs produced in the GIMP display correctly in IE. This is because we basically have the same design flaw as them - we assumed everything transparent would be a GIF, so in the GIMP we do transparency with 255 palette entries being totally opaque, and one palette entry being transparency.

For other programs, here are the tips you asked for: 1) alpha works fine in 32 bit pngs
2) In indexed PNGs, threshold the alpha channel before saving to see what it will look like in IE. Alternatively, save your image as a GIF, then load it and save the result as a PNG (or run it through gif2png). This will work fine in IE also.

Cheers,
Dave.

--
Dave Neary
Lyon, France

Do a search for "IE7" on google... it's a CSS file that can be included in a web page which fixes a bunch of stupid rendering bugs in IE, including, as I understand anyway, transparant PNGs.

HTH, HAND

alan

On Wed, 4 Aug 2004 09:13:04 -0400, Neil Watson wrote:

I know that IE has issues with transparent PNG files. I have noticed that it is somewhat random. Some files display correctly while others don't. Is there some type of method or work around that will create a transparent PNG file that IE will display correctly?

-- Neil Watson | Gentoo Linux Network Administrator | Uptime 64 days http://watson-wilson.ca | 2.6.5 AMD Athlon(tm) MP 2000+ x 2 _______________________________________________ Gimp-user mailing list
Gimp-user@lists.xcf.berkeley.edu
http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user

On Wed, Aug 04, 2004 at 04:07:41PM +0200, Dave Neary wrote:

Hi Neil,

Quoting Neil Watson :

I know that IE has issues with transparent PNG files. I have noticed that it is
somewhat random. Some files display correctly while others don't. Is there some type of method or work around that will create a transparent PNG file that IE will display correctly?

All PNGs produced in the GIMP display correctly in IE. This is because we basically have the same design flaw as them - we assumed everything transparent would be a GIF, so in the GIMP we do transparency with 255 palette entries being totally opaque, and one palette entry being transparency.

this is not true. gimp makes perfectly good pngs with alpha blending whatever the technical term is. if you index an image, you get that problem. that is how indexing works. it has nothing to do with gimp.

if you dont want to see crappy looking pngs dont use internet explorer.

carol

* Carol Spears [08-04-04 15:02]:

if you dont want to see crappy looking pngs dont use internet explorer.

I agree with you 100%. BUT! If I want to display a page on the net, for *everyone* to see, I must play to the *whole* crowd.

My own web site was horrible viewed with m$ eXploder, until the png's were changed under duress.

m$ has *made* their own standard and the lemmings have not objected. This lack of objection has given the perception of acceptance to m$'s deliberate efforts to make their own, and only their own, products desirable to those self same lemmings.

*Your* argument is religious.

On Wed, Aug 04, 2004 at 03:57:50PM -0500, Patrick Shanahan wrote:

* Carol Spears [08-04-04 15:02]:

I agree with you 100%. BUT! If I want to display a page on the net, for *everyone* to see, I must play to the *whole* crowd.

well, we usually agree.

and i am sorry for you about the whole crowd. the whole crowd is always so stupid. if smart boys like you would stop playing them things would probably get better quicker. or dumb girls like you. whatever you are.

My own web site was horrible viewed with m$ eXploder, until the png's were changed under duress.

my problem is that internet explorer seems to need a bigger place for a table than mozilla does. more pixels. probably mozilla number rules start with 0 and internet explorers start with 1 or something very basic and stupid like this. it screwed up our calendar when the church did not understand that.

then you got the wc3 that for some reason does not like tables.

isnt it boring? i am just trying to make web pages with images and text. i miss netscape3.

m$ has *made* their own standard and the lemmings have not objected. This lack of objection has given the perception of acceptance to m$'s deliberate efforts to make their own, and only their own, products desirable to those self same lemmings.

*Your* argument is religious.

no, religous is when you believe in a whole system so much that you are willing to pop any pill some man in a white coat with a signature you cannot read gives you. the mountain of information that you just have faith in its working and will help you as the people who just trust the medical institution and structure. that is a faith based religon and nothing i want to be a part of.

using software that actually displays text and images nicely together. that is just smart.

not having faith in the system that got it to me? sorry. i am sorry also.

carol

Patrick Shanahan Registered Linux User #207535 http://wahoo.no-ip.org @ http://counter.li.org HOG # US1244711 Photo Album: http://wahoo.no-ip.org/photos

Hi again,

Quoting Dave Neary :

All PNGs produced in the GIMP display correctly in IE.

Excuse me, this is just wrong :)

For other programs, here are the tips you asked for: 1) alpha works fine in 32 bit pngs

This is wrong too. Even with 32 bit RGBA PNGs, IE doesn't display them correctly. I don't know what I was thinking.

Cheers, Dave.

--
Dave Neary
Lyon, France

Hi Carol,

Quoting Carol Spears :

On Wed, Aug 04, 2004 at 04:07:41PM +0200, Dave Neary wrote:

All PNGs produced in the GIMP display correctly in IE. This is because we basically have the same design flaw as them - we assumed everything

transparent

would be a GIF, so in the GIMP we do transparency with 255 palette entries

being

totally opaque, and one palette entry being transparency.

this is not true. gimp makes perfectly good pngs with alpha blending whatever the technical term is.

Yup, and I was talking through my hat when I was talking about IE supporting them.

if you index an image, you get that problem. that is how indexing works. it has nothing to do with gimp.

Actually, no. That's how indexing works in the GIMP. But it is possible to have alpha-blended indexed images in PNG. PNG indexes may have an RGBA value, as opposed to just the RGB value that we limit things to. Here's the bug jimmac opened about this, with a couple of examples of indexed pngs with nice alpha channels. http://bugzilla.gnome.org/show_bug.cgi?id=86627

Cheers, Dave.

--
Dave Neary
Lyon, France

hi dave,
On Thu, Aug 05, 2004 at 09:01:45AM +0200, Dave Neary wrote:

Actually, no. That's how indexing works in the GIMP. But it is possible to have alpha-blended indexed images in PNG. PNG indexes may have an RGBA value, as opposed to just the RGB value that we limit things to. Here's the bug jimmac opened about this, with a couple of examples of indexed pngs with nice alpha channels. http://bugzilla.gnome.org/show_bug.cgi?id=86627

this makes no sense to me. it might be because i do not understand alpha. the way i understand it is that each pixel is assigned a number that represents a color ....

so you might be talking about (a light just turned on) a number that represents a color that has four parts. doh. except when you are still limited to 256 this will really effect the actual colors and make the image less eh, colorful after the indexing is done. meaning if all those shades of alpha need a different color from the 256 that can be used then less real colors can be used.

is this how that works?

carol

Hi Carol,

Carol Spears wrote:

this makes no sense to me. it might be because i do not understand alpha. the way i understand it is that each pixel is assigned a number that represents a color ....

That's right. The number is between 0 and 255. And that number gets mapped to the full color (that is, an RGB triplet in the GIMP). But there is no reason why this index could not refer to a different colour, say an RGBA color. So that a 50% opaque red could be part of your palette in index 23 (for example).

so you might be talking about (a light just turned on) a number that represents a color that has four parts.

Yup :) That's the one.

doh. except when you are still
limited to 256 this will really effect the actual colors and make the image less eh, colorful after the indexing is done. meaning if all those shades of alpha need a different color from the 256 that can be used then less real colors can be used.

is this how that works?

Well, kind of... since there are 256*256*256 RGB colors, and 256*256*256*256 RGBA colors, you end up with certain types of images that index less well, because you're picking 256 colors from a bigger set. But most images would do quite well. And you always have the option of throwing away the alpha channel, or thresholding it, if you want.

Cheers, Dave.