168763 - JPEG images display poorly in 16-bit color ("thousands") mode

Status: RESOLVED INCOMPLETE

(Core Graveyard :: Image: Painting, defect)

Description

[monkeypox37]

I looked to see if I could find something about this, sorry if it's a dupe.
You'll probably want to re-assign or whatever so I just left it as Chimera since
that's my main browser.

Chimera and Mozilla 1.1b (and possibly WinMozilla though I haven't tested it
personally) have banding in (some?) images in 'thousands of colors' mode as
demonstrated in the above URL. Other browsers tested - MSIE 5.2.1 and OmniWeb
don't show this banding. Switching to 'millions' corrects the issue for Chimera
& Mozilla but exacts a performance penalty.

See also thread discussing same for more accounts of the bug on Ars Technica,
I'll post the bug report number there in case anyone there feels like adding
their comments here:

http://arstechnica.infopop.net/OpenTopic/page?a=tpc&s=50009562&f=8300945231&m=2690903335

Comment 1

[Greg K.]

Confirmed using Chimera/2002090913 and FizzillaCFM/2002091014 on Mac OS X
10.1.5. Reassigning to Browser/Image: GFX.

Comment 2

[Sebastian Biallas]

Also on Win 98, using Build 2002-09-15-04 (16 bit color mode, no problem in 24
bit modes).

Comment 3

[Francesco De Francesco]

Unconfirmed on Windows XP using build 20020826 (Mozilla 1.1): the image displays
poorly due to 16-bit color depth but this happens under IE 6.0 and ACDsee 4.0, too.

Comment 4

[Jo Hermans]

This has seen before (see bug 154367 for instance). On a Mac, we could use
ColorSync (bug 16769) to convert 32-bit into 16-bit (it's not just for
color-matching, it also knows how to down sample correctly). But we need a
better general method for all platforms.

I haven't found a duplicate yet, except this : bug 14147 comment 13