80153 - PNGs incorrectly displayed

Status: RESOLVED WORKSFORME

(Core :: Graphics: ImageLib, defect)

Description

[Markus S.]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:0.9) Gecko/20010505
BuildID:    2001050515

Some PNGs are displayed too dark. It's a common problem, since IE and Opera, as
well as some image viewers have the same, but older Mozillas and
Netscape4.x/Netscap6 don't.

Reproducible: Always
Steps to Reproduce:
1. Enter URL

Actual Results:  PNG too dark

Expected Results:  PNG not too dark

It's too dark!

Comment 1

[Matthias Versen [:Matti]]

imagelib

Comment 2

[Keyser Sose]

*** This bug has been marked as a duplicate of 75558 ***

Comment 3

[Terri Preston]

Verified Duplicate

Comment 4

[James Paige]

This bug was incorrectly marked DUP of bug 75558 . That bug is about PNG alpha
transparency screwing up the background when the image is scaled. This one
appears to be a problem with PNG gamma support. Bonvolu maldupi?

Comment 5

[basic]

James: did you ever found out if this is not a dup?

If this is still an issue and it is not a dup we will need a testcase and some
clear description of what is wrong. If that is not the case ignore me.

Comment 6

[James Paige]

I am absolutely positively dead-certain that this is NOT a duplicate of bug
75558 , based on my reading of the PNG spec. This bug's description describes a
problem with gamma correction that has nothing at all to do with alpha. Bug
75558 is an alpha problem, which has absolutely nothing to do with gamma.

But based on the test-suite at http://libpng.org/pub/png/pngsuite.html I think
that Mozilla is currently correctly supporting PNG gamma now.

Comment 7

[James Paige]

resolving worksforme (just because I like a nice clean bug system)

If the reporter has any test-case images that Mozilla still renders wrong, he
may re-open.