jpeg image does not show in background

jpeg image does not show in background

[Piscium]

I got a jpeg image from the net, set it as background, and it was not
shown. I converted it to png and the png was shown fine. I am trying
to find why jpeg background is not working (I do have insmod jpeg and
insmod png).

Googling I found this ubuntu bug that includes a patch:
https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/541670

The author welcomes pushing upstream, but as the bug is not even
assigned, I assume that never happened (I searched this list archives
for "huffman" and there was no recent message).

I know nothing about jpeg. My question is if there are known
limitations on the types of jpeg file that can be read by grub2, and
if so, what they are. I am using v. 1.98.

Re: jpeg image does not show in background

[Vladimir 'φ-coder/phcoder' Serbinenko]

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On 10/01/2010 02:10 PM, Piscium wrote:
> I got a jpeg image from the net, set it as background, and it was not
> shown. I converted it to png and the png was shown fine. I am trying
> to find why jpeg background is not working (I do have insmod jpeg and
> insmod png).
>
> Googling I found this ubuntu bug that includes a patch:
> https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/541670
>
> The author welcomes pushing upstream, but as the bug is not even
> assigned, I assume that never happened (I searched this list archives
> for "huffman" and there was no recent message).
>
> I know nothing about jpeg. My question is if there are known
> limitations on the types of jpeg file that can be read by grub2, and
> if so, what they are. I am using v. 1.98.
>
>   
Upgrade
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>
>   


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



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Re: jpeg image does not show in background

[Piscium]

2010/10/1 Vladimir 'φ-coder/phcoder' Serbinenko <phcoder@gmail.com>:

> Upgrade

I might try that. In the meantime I have applied the patch provided in
the Ubuntu bug to 1.98 but it has not made any difference (still no
image).

Re: jpeg image does not show in background

[Piscium]

2010/10/1 Piscium <groknok@gmail.com>:
> 2010/10/1 Vladimir 'φ-coder/phcoder' Serbinenko <phcoder@gmail.com>:
>
>> Upgrade

So far I have only used grub2 released versions, downloaded as tar files.

How to get the main development version (hopefully relatively solid)?
I suppose with
    bzr branch xxxx
but what is xxxx?

The wiki is not that clear. I found this, but am not sure if it is the
best version:
http://grub.enbug.org/ExperimentalBranch

jpeg image does not show in background

[Tom Davies]

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jpg compression does some horrible things to pictures especially if you try to 
resize after cropping or doing anythign to them really.  Why not stay with png?
Regards from
Tom :)



      

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Re: jpeg image does not show in background

[Piscium]

2010/10/1 Piscium <groknok@gmail.com>:

> How to get the main development version (hopefully relatively solid)?
> I suppose with
>    bzr branch xxxx
> but what is xxxx?
>
> The wiki is not that clear. I found this, but am not sure if it is the
> best version:
> http://grub.enbug.org/ExperimentalBranch
>

OK, I found this in the wiki:
"GRUB 2 is actively developed. If you have problems with it, then
please try the current BZR version (the SVN repository will no longer
be updated) before reporting bugs. NOTE: The BZR repo doesn't support
source-browsing, so you'll need to get a copy of the repo with bzr
branch http://bzr.savannah.gnu.org/r/grub/trunk/grub. "

I guess this is what I need, but I only saw it now because it is
_above_ the "Development" heading.

Under that heading there is an item that says;
  Bazaar Repository
which points to
  https://savannah.gnu.org/bzr/?group=grub
And that is what I saw first.

So one suggestion to improve the wiki page is:
- Put the paragraph I quoted _under_ the  "Development" heading to
make it more prominent.
- Remove the link to https://savannah.gnu.org/bzr/?group=grub as I am
not sure it is helpful, or alternatively explain it better.

Re: jpeg image does not show in background

[Piscium]

On 1 October 2010 15:15, Tom Davies <tomdavies04@yahoo.co.uk> wrote:
> jpg compression does some horrible things to pictures especially if you try
> to resize after cropping or doing anythign to them really.  Why not stay
> with png?

That is a good point. And I might add that it takes only one minute to
convert a file from jpeg to png (manually).

OTOH if someone is looking for a background on the net, there are far
more jpegs than pngs available. And jpeg is supposed to work with
grub2. And today I have some free time or I would not be playing with
grub2!

Re: jpeg image does not show in background

[Piscium]

2010/10/1 Vladimir 'φ-coder/phcoder' Serbinenko <phcoder@gmail.com>:

> Upgrade

OK, I built and installed the trunk version, and still the jpeg is not shown.

If jpeg works for some people, this could be hardware related. My
monitor is 1920X1080. The jpeg file is big, but smaller than the png:
-rw-r--r--. 1 root root 2182354 Oct  1 10:48
/boot/grub/extra/green_mountains.jpg
-rw-r--r--. 1 root root 3402218 Oct  1 12:07
/boot/grub/extra/green_mountains.png

This is a low priority issue (and png works), so I will stop here
unless somewhat has some idea.

Re: jpeg image does not show in background

[BandiPat]

On 10/01/2010 12:11 PM, Piscium wrote:
> 2010/10/1 Vladimir 'ö-coder/phcoder' Serbinenko<phcoder@gmail.com>:
>
>> Upgrade
>
> OK, I built and installed the trunk version, and still the jpeg is not shown.
>
> If jpeg works for some people, this could be hardware related. My
> monitor is 1920X1080. The jpeg file is big, but smaller than the png:
> -rw-r--r--. 1 root root 2182354 Oct  1 10:48
> /boot/grub/extra/green_mountains.jpg
> -rw-r--r--. 1 root root 3402218 Oct  1 12:07
> /boot/grub/extra/green_mountains.png
>
> This is a low priority issue (and png works), so I will stop here
> unless somewhat has some idea.
>
> _______________________________________________

I don't think it's the monitor's resolution that you should be concerned 
with, but your graphics cards framebuffer.  Since the graphics card's 
engine hasn't been fully activated yet, you are relegated to the 
framebuffer only to display images.  Normally this will be 1280x1024 or 
smaller.  Have you tried a 1280x1024 size jpeg for your background image?

Now I could be wrong, so hopefully someone will correct me, if that is 
the case.

Good luck!
Patrick

Re: jpeg image does not show in background

[Colin D Bennett]

On Fri, 1 Oct 2010 16:40:38 +0100
Piscium <groknok@gmail.com> wrote:

> On 1 October 2010 15:15, Tom Davies <tomdavies04@yahoo.co.uk> wrote:
> > jpg compression does some horrible things to pictures especially if
> > you try to resize after cropping or doing anythign to them really.
> > Why not stay with png?
> 
> That is a good point. And I might add that it takes only one minute to
> convert a file from jpeg to png (manually).

Well, converting from JPEG to PNG is really pointless since it won't
improve quality at all--the details already lost in JPEG compression
can't be recovered.

Regards,
Colin

Re: jpeg image does not show in background

[Colin D Bennett]

On Fri, 1 Oct 2010 17:11:22 +0100
Piscium <groknok@gmail.com> wrote:

> 2010/10/1 Vladimir 'φ-coder/phcoder' Serbinenko <phcoder@gmail.com>:
> 
> > Upgrade
> 
> OK, I built and installed the trunk version, and still the jpeg is
> not shown.
> 
> If jpeg works for some people, this could be hardware related. My
> monitor is 1920X1080. The jpeg file is big, but smaller than the png:
> -rw-r--r--. 1 root root 2182354 Oct  1 10:48
> /boot/grub/extra/green_mountains.jpg
> -rw-r--r--. 1 root root 3402218 Oct  1 12:07
> /boot/grub/extra/green_mountains.png
> 
> This is a low priority issue (and png works), so I will stop here
> unless somewhat has some idea.

There must be some JPEG feature used by this particular image that the
GRUB JPEG module doesn't support (progressive encoding? EXIF? ???).

Regards,
Colin

Re: jpeg image does not show in background

[Piscium]

On 1 October 2010 19:10, Colin D Bennett <colin@gibibit.com> wrote:
> On Fri, 1 Oct 2010 16:40:38 +0100
> Piscium <groknok@gmail.com> wrote:
>
>> On 1 October 2010 15:15, Tom Davies <tomdavies04@yahoo.co.uk> wrote:
>> > jpg compression does some horrible things to pictures especially if
>> > you try to resize after cropping or doing anythign to them really.
>> > Why not stay with png?
>>
>> That is a good point. And I might add that it takes only one minute to
>> convert a file from jpeg to png (manually).
>
> Well, converting from JPEG to PNG is really pointless since it won't
> improve quality at all--the details already lost in JPEG compression
> can't be recovered.

Well, yes. The point of converting is when grub2 for some reason
displays png well but cannot display jpeg - conversion then is a
workaround.

Re: jpeg image does not show in background

[Vladimir 'φ-coder/phcoder' Serbinenko]

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On 10/01/2010 08:12 PM, Colin D Bennett wrote:
> On Fri, 1 Oct 2010 17:11:22 +0100
> Piscium <groknok@gmail.com> wrote:
>
>   
>> 2010/10/1 Vladimir 'φ-coder/phcoder' Serbinenko <phcoder@gmail.com>:
>>
>>     
>>> Upgrade
>>>       
>> OK, I built and installed the trunk version, and still the jpeg is
>> not shown.
>>
>> If jpeg works for some people, this could be hardware related. My
>> monitor is 1920X1080. The jpeg file is big, but smaller than the png:
>> -rw-r--r--. 1 root root 2182354 Oct  1 10:48
>> /boot/grub/extra/green_mountains.jpg
>> -rw-r--r--. 1 root root 3402218 Oct  1 12:07
>> /boot/grub/extra/green_mountains.png
>>
>> This is a low priority issue (and png works), so I will stop here
>> unless somewhat has some idea.
>>     
> There must be some JPEG feature used by this particular image that the
> GRUB JPEG module doesn't support (progressive encoding? EXIF? ???).
>
>   
EXIF is skipped correctly but some kind of special encoding might be a
problem

@Piscium: can you file a bug report on savannah and attach the .jpg (or
at least post the URL) if license permits
> Regards,
> Colin
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>
>   


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



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Re: jpeg image does not show in background

[Piscium]

On 1 October 2010 17:44, BandiPat <magicpage91@earthlink.net> wrote:

> I don't think it's the monitor's resolution that you should be concerned
> with, but your graphics cards framebuffer.  Since the graphics card's engine
> hasn't been fully activated yet, you are relegated to the framebuffer only
> to display images.  Normally this will be 1280x1024 or smaller.

Well, 1920X1080 displays well with png with a file of 3.2 Mbytes.

> Have you tried a 1280x1024 size jpeg for your background image?

Following your suggestion I hacked grub.cfg to display 1280x1024. Then
I got two other images of this resolution, one png, one jpeg. The png
displayed well, the jpeg didn't.

At this point I thought that no jpeg could be displayed. To test this
hypothesis I started Gimp and created a basic jpeg, with some
scribbles with a red brush on a white background. The file was
obviously much smaller than the others I had tested, only 78 Kbytes.
This file displayed well.

The conclusion appears to be that the jpeg module in grub2 is very
fussy about the files that it displays. Note there was nothing special
about the files I wanted to display. The "green_mountains" was taken
from a blog, and the two 1280x1024 images were taken from the Gnome
Art website.

There is a file grub-core/video/readers/jpeg.c. It has plenty of debug
statements like:
    "grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: huffman decode fails");

Is there some easy way to read the text of these messages? (I have no
JTAG and my hardware does not support virtualization).

Re: jpeg image does not show in background

[Vladimir 'φ-coder/phcoder' Serbinenko]

On 10/01/2010 08:55 PM, Piscium wrote:
> On 1 October 2010 17:44, BandiPat <magicpage91@earthlink.net> wrote:
>
>   
>> I don't think it's the monitor's resolution that you should be concerned
>> with, but your graphics cards framebuffer.  Since the graphics card's engine
>> hasn't been fully activated yet, you are relegated to the framebuffer only
>> to display images.  Normally this will be 1280x1024 or smaller.
>>     
> Well, 1920X1080 displays well with png with a file of 3.2 Mbytes.
>
>   
>> Have you tried a 1280x1024 size jpeg for your background image?
>>     
> Following your suggestion I hacked grub.cfg to display 1280x1024. Then
> I got two other images of this resolution, one png, one jpeg. The png
> displayed well, the jpeg didn't.
>
> At this point I thought that no jpeg could be displayed. To test this
> hypothesis I started Gimp and created a basic jpeg, with some
> scribbles with a red brush on a white background. The file was
> obviously much smaller than the others I had tested, only 78 Kbytes.
> This file displayed well.
>
> The conclusion appears to be that the jpeg module in grub2 is very
> fussy about the files that it displays. Note there was nothing special
> about the files I wanted to display. The "green_mountains" was taken
> from a blog, and the two 1280x1024 images were taken from the Gnome
> Art website.
>   
It's not really "nothing particular". With pictures taken by my camera
it works fine.
> There is a file grub-core/video/readers/jpeg.c. It has plenty of debug
> statements like:
>     "grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: huffman decode fails");
>
> Is there some easy way to read the text of these messages? (I have no
> JTAG and my hardware does not support virtualization).
>
>   
They aren't debug messages but error messages which are shown if you
call background_image manually.
Bluepill extensions are useless for debugging GRUB and sticking to the
simplest qemu is the best option. Qemu works on any hardware.
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>
>   


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko

Re: jpeg image does not show in background

[Piscium]

2010/10/1 Vladimir 'φ-coder/phcoder' Serbinenko <phcoder@gmail.com>:

> On 10/01/2010 08:55 PM, Piscium wrote:

>> The conclusion appears to be that the jpeg module in grub2 is very
>> fussy about the files that it displays. Note there was nothing special
>> about the files I wanted to display. The "green_mountains" was taken
>> from a blog, and the two 1280x1024 images were taken from the Gnome
>> Art website.
>>

> It's not really "nothing particular". With pictures taken by my camera
> it works fine.

The site I mentioned, Gnome Art is this:
http://art.gnome.org/backgrounds

It is where some people come to get nice background images, and not
just Gnome users. For example, in my Windows PC at work I have a
background from this site. So it would be good if pictures from this
site could be displayed with grub2. They are just normal pictures.

In fact I think the site could be used as a test resource for the
grub2 background image feature, as it has images created by various
people in various sizes and with various cameras and software
packages.


>> There is a file grub-core/video/readers/jpeg.c. It has plenty of debug
>> statements like:
>>     "grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: huffman decode fails");
>>
>> Is there some easy way to read the text of these messages? (I have no
>> JTAG and my hardware does not support virtualization).
>>
>>
> They aren't debug messages but error messages which are shown if you
> call background_image manually.

By loading the image files manually on the command line I got this
error message for both problem files:
"jpeg: invalid 0xFF in data stream"

This comes from jpeg.c, line 124.

I have created a bug report as you requested, unfortunately I could
not attach the said files as they exceed the site limit. If you want I
can email the files to you or upload to some temporary place of your
choice. (The file sizes are 2.1 Mb and 577 Kb).

Re: jpeg image does not show in background

[Piscium]

2010/10/2 Piscium <groknok@gmail.com>:

> I have created a bug report as you requested, unfortunately I could
> not attach the said files as they exceed the site limit. If you want I
> can email the files to you or upload to some temporary place of your
> choice. (The file sizes are 2.1 Mb and 577 Kb).
>

OK, I managed to get links to the two problem files:

http://ftp.acc.umu.se/pub/GNOME/teams/art.gnome.org/backgrounds/NATURE-AnotherCountrySunset_1280x1024.jpg

http://wallpaper4god.files.wordpress.com/2009/09/wallpaper-1080p-4.jpg

jpeg image does not show in background

[Tom Davies]

Hi :)

From experiences with my company's website i would say convert the image from 
jpg to png asap while you have it as good as it will ever get.  For the website 
i then try to clean the image up a bit if possible (given time limitations & 
likely size of useful final image).  After that any cropping or re-sizing causes 
less damage to the image.

Most cameras default to jpegs which are generally pretty good nowadays, it's 
only when you start messign with the image that problems creep in so doing a 
conversion to a better format seems sensible early on in the process.

Jpg is a horrible format but previously cameras used to use even worse quirky 
formats that were difficult to convert into anything useful.  They used to also 
allow slightly more knowledgeable people to switch to bitmaps were much better 
but back then it meant a camera conly hold about 4 images or something stupid.

Just because a lot of people use a particular thing does not mean that it is the 
best thing to use.  Generally i would rather ask experts that work with a 
variety of similar things a lot and ask them which they prefer and why.  Often 
the answers are that 1 thin is better for some stuff while another is better for 
other circumstances.

Take Windows for example.  A LOT of people use Windows so does that mean that 
Windows is the best? Imo that would raise the question "best at what?".  
Certainly it is not the best server OS!  I would argue that on most criteria 
that makes Windows the "best" DamnVulnerableLinux would be better.

I don't know how to reply to the list properly.  I tried the instructions as 
best i could and experimented but this is the only way that seems to work.  I 
hit "reply" and then copy&paste into the subject line.  Someone magically and 
kindly sorts it for m from there.  If there is someway of getting this stupid 
yahoo thing to give a better result then please let me know.

Regards from
Tom :)



     

Re: jpeg image does not show in background

[Vladimir 'φ-coder/phcoder' Serbinenko]

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On 10/02/2010 09:48 PM, Tom Davies wrote:
> Hi :)
>
> From experiences with my company's website i would say convert the image from 
> jpg to png asap while you have it as good as it will ever get.  
>   
This isn't a place for format flamewar. Issue at hand is real and
concrete and should be fixed as such.

-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



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Re: jpeg image does not show in background

[Vladimir 'φ-coder/phcoder' Serbinenko]

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On 10/02/2010 11:17 AM, Piscium wrote:
> 2010/10/1 Vladimir 'φ-coder/phcoder' Serbinenko <phcoder@gmail.com>:
>
>   
>> On 10/01/2010 08:55 PM, Piscium wrote:
>>     
>   
>>> The conclusion appears to be that the jpeg module in grub2 is very
>>> fussy about the files that it displays. Note there was nothing special
>>> about the files I wanted to display. The "green_mountains" was taken
>>> from a blog, and the two 1280x1024 images were taken from the Gnome
>>> Art website.
>>>
>>>       
>   
>> It's not really "nothing particular". With pictures taken by my camera
>> it works fine.
>>     
> The site I mentioned, Gnome Art is this:
> http://art.gnome.org/backgrounds
>
> It is where some people come to get nice background images, and not
> just Gnome users. For example, in my Windows PC at work I have a
> background from this site.
This isn't a place for advertisement.
>  So it would be good if pictures from this
> site could be displayed with grub2. They are just normal pictures.
>
> In fact I think the site could be used as a test resource for the
> grub2 background image feature, as it has images created by various
> people in various sizes and with various cameras and software
> packages.
>
>
>   
>>> There is a file grub-core/video/readers/jpeg.c. It has plenty of debug
>>> statements like:
>>>     "grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: huffman decode fails");
>>>
>>> Is there some easy way to read the text of these messages? (I have no
>>> JTAG and my hardware does not support virtualization).
>>>
>>>
>>>       
>> They aren't debug messages but error messages which are shown if you
>> call background_image manually.
>>     
> By loading the image files manually on the command line I got this
> error message for both problem files:
> "jpeg: invalid 0xFF in data stream"
>
>   
This is very insightful. The issue is because of optional (and useless)
padding in jpeg. I know how to fix it but is too tired right now
(admiring beauties of my country takes sometimes effort)
> This comes from jpeg.c, line 124.
>
> I have created a bug report as you requested, unfortunately I could
> not attach the said files as they exceed the site limit. If you want I
> can email the files to you or upload to some temporary place of your
> choice. (The file sizes are 2.1 Mb and 577 Kb).
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>
>   


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



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