Firefox 3 displays JPEG with much colour banding compared to Firefox 2

[Ralph Corderoy]

Binary package hint: firefox-3.0

Ubuntu 8.04, firefox-3.0 3.0+nobinonly-0ubuntu0.8.04.1, firefox-2 2.0.0.15+1nobinonly-0ubuntu0.8.04.2.

Firefox 3 displays many JPEG photos with much banding in the colour compared to Firefox 2. Attached is a sample JPEG, two screenshots of FF 2 and 3 viewing the same HTML file that uses that JPEG, and the output of xdpyinfo since I've a 16bpp root window and that may be pertinent. This makes Firefox 3 impractical for viewing and rating photographs.

[Michael Rooney (mrooney)]

Hi Ralph, thanks for using Ubuntu and thanks for your bug report! I am on Firefox 3 here (3.0+nobinonly-0ubuntu0.8.04.1) and see the original image just as you do in Firefox 2, without the banding, so I can't confirm this issue.

What exactly do you mean by a 16bpp root window? I am unaware of what that means, but since this doesn't appear to be a universal Firefox issue on a standard install, it may be something about your specific system setup. Any ideas?

[Ralph Corderoy (ralph-inputplus)]

Mike, thanks for the quick response.

> I am on Firefox 3 here (3.0+nobinonly-0ubuntu0.8.04.1) and see the
> original image just as you do in Firefox 2, without the banding, so I
> can't confirm this issue.

Interesting. I thought it may be particular to my setup as I couldn't
find any existing bugs and it seems such an obvious visual abberation.

> What exactly do you mean by a 16bpp root window? I am unaware of what
> that means, but since this doesn't appear to be a universal Firefox
> issue on a standard install, it may be something about your specific
> system setup. Any ideas?

Firstly, I've a bog standard Ubuntu 8.04 Desktop install. I've no
packages from non-Ubuntu respositories, and no non-package software. I
meant above that my X server's root window is 16 bits per pixel. In
other words, my Gnome/X desktop can display 2**16 different colours,
65,536.

This is due to my stalwart old graphics card. Most modern desktop
systems would have 24bpp, but historically 16bpp or even 8bpp desktops
were common. It may be that some PDAs or phones these days still have
16bpp graphics.

Anyway, there's clearly a regression in FF3 over FF2 and its probably to
do with the fact my graphics card has less bits per pixel than most
other FF3 users since you don't see the same issue. Although, given I'd
have thought FF3 just uses a library to do the decompression to a
certain colourspace, I'm puzzled as to why that would have changed
between versions.

Xorg(1) can be started with `-depth 16', or have a look at the
DefaultDepth setting in the Screen section of /etc/X11/xorg.conf.

[Pedro Villavicencio (pedro)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. You reported this bug a while ago and there hasn't been any activity in it recently. We were wondering is this still an issue for you? Could you try to reproduce the same with Ubuntu 8.10 or 9.04? Thanks in advance.

[Clark Dever (clarkdever)]

I also am having this issu also.

Kubuntu
Ubuntu 8.10 \n \l

FF3.0.5

Running on an HP Pavilion dv1000 Laptop

Screenshots attached.

[Clark Dever (clarkdever)]

This is the same page in konqueror

[Ralph Corderoy (ralph-inputplus)]

I'm not convinced it's the same problem. What does the command

    xdpyinfo | grep depths

give on your system? For me, it shows

    depths (7): 16, 1, 4, 8, 15, 24, 32

meaning the display is 16 bits per pixel deep.

Also, the screenshots are JPEGs. This is a lossy compression format so we can't tell what the problems are caused by Firefox and what's caused by JPEG throwing away detail in compressing. The PNG image format is much better for this kind of thing; it records precisely each pixel you have on your screen.

[Clark Dever (clarkdever)]

Hi Ralph,

depths (7): 24, 1, 4, 8, 15, 16, 32

[Clark Dever (clarkdever)]

Note the banding around his ear.

Here is the the konqueror version for comparison. (It renders slightly differently, I don't know why the image is a different size)

Thanks,
Clark

[Ralph Corderoy (ralph-inputplus)]

Clark, would you mind changing the status from Incomplete to Confirmed; I'm not allowed to confirm by own bugs apparently. It may then get some attention.

[Clark Dever (clarkdever)]

Ralph confirmed the bug via screenshots.

[ere (robert-erent)]

Similar problem: The same picture seen in the background of webpage in Firefox 3-06 is rendered with "level-curves", but saved (using Save Complete xpi, otherwise would not save) viewed in EOG viewer looks fine.

xdpyinfo | grep depths ... gives this: depths (7): 16, 1, 4, 8, 15, 24, 32

[ere (robert-erent)]

Extracted and viewed using EOG it looks quite OK (Users of affected systems should probably save it to desktop and view using EOG or similar to see different rendering.)

[ere (robert-erent)]

Ooops, no need to save-and-view PNG, PNGs are rendered OK.

[Ralph Corderoy (ralph-inputplus)]

> xdpyinfo | grep depths ... gives this: depths (7): 16, 1, 4, 8, 15, 24, 32

This shows you too have a 16bpp X display. So it's definitely a Firefox regression with Ubuntu's move from Firefox 2 to Firefox 3 for displaying JPEGs on a 16bpp X display. You should find that using Firefox 2 (package firefox-2 in 8.04 for example) displays that page fine.

Obviously, trying to view photographs (JPEGs) with FF3 is pointless, rendering (NPI) it useless for common use.

[ere (robert-erent)]

Another comparison - Opera 9.64 and Firefox 2 (Intrepid)... Opera behaves similarly as FF3, FF2 seems to display more colors, though xwininfo showed equal depth (16) after clicking on each of windows. (As far as I know xorg.conf in tested 9-yrs old IBM comp doesn't contain color depth at all for some reason but both xdpyinfo and xwininfo showed 16.)

[Ralph Corderoy (ralph-inputplus)]

So it's probably a bug in an underlying library that both Opera and FF3
use, whereas FF2 either doesn't use it, or is using an older version.

Someone with a bit of Firefox internals knowledge could quickly bounce
this onto the right package for some TLC...

[Ralph Corderoy (ralph-inputplus)]

Still clearly present in 8.04's new firefox 3.6.6+nobinonly-0ubuntu0.8.04.2 package. 8899.jpg, above, viewed at 100% in Firefox and eog(1) look very different. Heavy banding in Firefox.

[Ralph Corderoy (ralph-inputplus)]

Well, it's two and a half years later, I've upgraded from 8.04 to 10.10,
and Firefox 3 still has this JPEG display regression compared to Firefox
2 back then. The sample image I provided back then still displays
terrible banding on this 16bpp display, as can be seen in the
differences between ff[23].8899.png from that time.

Package firefox 3.6.15+build1+nobinonly-0ubuntu0.10.10.1.

Can someone set the Importance please? Not being able to view photos
for judgement and selection is a real PITA. At least on 8.04 I could
run up Firefox 2 but 10.10 (rightly) doesn't provide that any more so
that workaround has gone.

[ere (robert-erent)]

Hi,

is there a quick way to force my PC running 10.04LTS to go to 16-bit mode?
I would carry it out when having more free time. (In 24-bit mode on probably
16-bit display the differences between Opera and current FF are not
relevant, if
existent at all.)

Sincerely
R.

Dňa 13.03.2011 15:04, Ralph Corderoy wrote / napísal(a):
> Well, it's two and a half years later, I've upgraded from 8.04 to 10.10,
> and Firefox 3 still has this JPEG display regression compared to Firefox
> 2 back then. The sample image I provided back then still displays
> terrible banding on this 16bpp display, as can be seen in the
> differences between ff[23].8899.png from that time.
>
> Package firefox 3.6.15+build1+nobinonly-0ubuntu0.10.10.1.
>
> Can someone set the Importance please? Not being able to view photos
> for judgement and selection is a real PITA. At least on 8.04 I could
> run up Firefox 2 but 10.10 (rightly) doesn't provide that any more so
> that workaround has gone.
>