Some help is needed here to certify. Tested with older versions and Gecko/20001023, win98. From long time I saw PNG images with portions 100% transparent (in the alpha channel) that over some background colors is possible to note that these images are not rendered completelly 100% transparent (in the 100% transp areas). http://www.libpng.org/pub/png/pngs-img.html Note the toucan images. If you have a notebook TFT display, look from the bottom - is easy to note :-). When background are light colors or very dark it's difficult to see. With this test that is a green background I can see. In a lot of other pages with PNG just change the background for something like #aaaaaa and you will note.
Maybe a Windows thing? They look pretty damn transparent on Linux 2000-10-27 nightly trunk build, XFree86 DRI CVS snapshot, 16-bit color.
Summary: RFE - PNG alpha with 100% transparency is not rendered 100% transparent. → RFE - PNG alpha with 100% transparency is not rendered 100% transparent.
Tested with Linux, 2000-09-29 Netscape 6 Build just to verify behavior with Linux. Agreed - pretty and 100% transparent (for the eyes).
Tested the actual transparency with a graphics application. All of the toucan images transparencies are correct here on Windows 2000 (2000102905) trunk bits.
Aha! Note the user mentions a TFT screen. And what's different about a TFT screen compared with most decent hardware these days? 16bpp frame buffer! This could very well be a different rendering path for images (no matter whether transparent) and page backgrounds. On 24bpp it all comes out in the wash, but on 16bpp or 8bpp you might see tiny but perceptible differences. Owner/ testers - tell your OS or Windowing system to use 16bpp, and repeat the experiments you tried earlier. The differences may need VERY GOOD eye sight, but they are probably there. Since this behaviour won't be seen on decent display hardware it is only a minor niggle and shouldn't be corrected while engineer resources are needed elsewhere. Note that WinIE and NS4x won't display the transparency anyway so we're already ahead.
Agreed, this may be a behavior in the 65K color mode. Tests welcome to help confirming this bug. If this is a bug in the nightly build I agreed that this is minor. Also that is an easy fix.
Please check 51179 for another possible cause of the symptoms in Marcio's original bug report. Here I cannot _see_ the problem, but a screenshot and an image editor's "eyedropper" tool makes it obvious in short order. The TFT 16bpp thing would exacerbate the problem in 51179 if I'm right.
umm.. Win98 desktop. pIII 550MHz Moz Build: 2000121508 16bit colour - Toucans background not 100% transparent. 24/32bit colour - Toucans background transparent. If it will help I can throw in some screen shots of the difference? However my display was set to 16bit by default.. would be nice if 16bit would show transparency.. is this possible, or imporrible due to the capabilites of 16bit display? Anyway.. I can see what the reporter saw, so I am confirming. However I think this could be a duplicate of bug 19283 - that is marked fixed, so I'm not too sure what's going on.
Status: UNCONFIRMED → NEW
Ever confirmed: true
Reassigning to dcone.
Assignee: kmcclusk → dcone
Using Mozilla 0.7 on Linux, you can see transparent PNG images aren't 100% transparent when you stack them. The more you stack, the more apparent it becomes. Will attach a screen snapshot of this behavior.
The images in the attached example havea visual depth of 16.
staked transp png was a great idea!!
Status: NEW → ASSIGNED
Summary: RFE - PNG alpha with 100% transparency is not rendered 100% transparent. → RFE - PNG alpha with 100% transparency is not rendered 100% transparent. [gfx][png]
Target Milestone: --- → Future
http://Games.GadgetScope.com/ - View in 16 bit color Transparent areas are not being rendered properly - instead there almost seems to be an ordered dither occuring that isn't necessary. Looks OK in 32 bit color. Build: 2001062004 Win98 + 3dfx Voodoo3 3000 800x600x16
WFM 2002022103/WinXP@16bbp neither do the parrots look wrong (tested by enhancing a screenshots contrast with the GIMP) nor does http://games.gadgetscope.com/ show the errors displayed by the screenshot. anyone still seeing thist? otherwise WFM?
Marking works for me.. if anyone see's the problem.. reopen. and describe exact symptoms.
Status: ASSIGNED → RESOLVED
Last Resolved: 17 years ago
Resolution: --- → WORKSFORME
Mass removing self from CC list.
Now I feel sumb because I have to add back. Sorry for the spam.
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