53878 - Mozilla color image handling code is different from the bgcolor color handling code

Status: RESOLVED FIXED

(Core :: Graphics: ImageLib, defect, P3)

Description

[xkahn]

From Bugzilla Helper:
User-Agent: Mozilla/4.75 [en] (X11; U; Linux 2.2.16 i686)
BuildID:    2000091312

The bgcolor attribute rounds to one color in the color cube, and the image code
rounds to another in 16 bit mode.  (At least on Linux.)  Check out this URL to
test:
http://hotwired.lycos.com/webmonkey/00/37/stuff2a/complete_websafe_216/test.html

Razorfish wrote an article on the problem which can be found here:
http://hotwired.lycos.com/webmonkey/00/37/index2a.html?tw=design

This link ( http://www.zoned.net/~xkahn/boxes.png ) shows mozilla rendering this
page on Linux in 16bit True color mode (here is the xdpyinfo)
  default visual id:  0x22
  visual:
    visual id:    0x22
    class:    TrueColor
    depth:    16 planes
    available colormap entries:    64 per subfield
    red, green, blue masks:    0xf800, 0x7e0, 0x1f
    significant bits in color specification:    6 bits


Reproducible: Always
Steps to Reproduce:
1. Load the URL in 16bit mode.
2. Look for boxes within boxes.  Each one you see is a bug in the color
handling.

Actual Results:  Boxes within boxes everywhere!

Expected Results:  A nice clean set of solid boxes.

Gimp says:  CCCCCC bgcolor is: C8CCC8, and CCCCCC image is dithered to: c8c8c8
and c0ccc0.

Comment 1

[Syd Logan]

You have to look carefully, some of the images that have a high luminosity (like
cccc99) are easier to see a problem with than those which are less luminous. I
saw this too on my 16-bit system.

Comment 2

[Asa Dotzler [:asa]]

setting bug status to New

Comment 3

[Paul Wyskoczka]

Updating QA Contact

Comment 4

[Paul Wyskoczka]

Adding myself to cc list

Comment 5

[pnunn]

All pnunn bugs reassigned to Pav, who is taking over
the imglib.

Comment 6

[basic]

Seeing this on build 2001070108 win32 on win98

setting os to all

are there any plans to fix this?

Comment 7

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Is this a duplicate of bug 1759?

Comment 8

[Christian :Biesinger (don't email me, ping me on IRC)]

dbaron, I don't think so, since in this bug no transparency is involved (as I
understand it)

Comment 9

[Cees T.]

Test page looks fine in Firefox 2.0.0.2 on K/Ubuntu 6.10.

Comment 10

[Cees T.]

Sorry, it turns out i'm running with 24 bit colors. KDE doesn't appear to have a color depth setting in its GUI. I'll test and report back if it's OK.

Comment 11

[Jeff Muizelaar [:jrmuizel]]

We no longer do dithering.