152192 - Colors in images and in HTML don't mean the same thing

Status: RESOLVED FIXED

(Core :: Graphics: ImageLib, defect)

Description

[Bruce Brackbill]

I set a image to a websafe color.  Mozilla ( and
NS 4.7 for that matter ) displays the color differently
than it is set to in the images palette.
IE displays the image correctly.

See attachment for example.

I am using win 95 16bit color.

Comment 1

[Bruce Brackbill]

Attachment: websafe 1pixel gif (CCCC99_websafe-color-image.gif ) for use in the following attachment

Comment 2

[Bruce Brackbill]

Attachment: To present the 'color problem" I use the #CCCC99 gif as a td background in this attachment

Comment 3

[Anthony DeRobertis]

I see this on Linux with 2002072204. 16-bit truecolor.

On the left, I get c5ce94. On the right, cdce9c.

In GIMP, if I create a splotch of CCCC99, then past in a screen shot, I'm not
really sure which is closer. [Gimp is dithering, btw.] Gimp does show the GIF
has CCCC99.

<rant>How can converting from 24-bit to 16-bit truecolor be so hard? It's only
taking the five high bits of each byte. perl -e 'printf "%X\n", 0xCCCC99 &
0xF8F8F8' says C8C898. I think X11 is using my display for stenagraphy ;-)</rant>

Comment 4

[Anthony DeRobertis]

One thing I forgot to add: In neither case is Mozilla dithering.

Comment 5

[Jo Hermans]

see discussion in bug 114701

Comment 6

[Jeff Muizelaar [:jrmuizel]]

We don't dither images by hand anymore, so this should no longer be a problem.