Do you use lossless JPEG recompression tools?

On Fri, 18 Jan 2008 10:21:18 -0800 (PST), Sachin Garg
<schngrg.RemoveThis@gmail.com> wrote in
<dc2987e5-b758-45ef-b644-0df4f9bb6440.RemoveThis@c4g2000hsg.googlegroups.com>:

>There are a number of tools available which can do "lossless"
>compression of jpeg files, they get around 20-25% compression. There
>are both commercial/proprietary (StufIt) and free/open-source options
>(PackJPG, PAQ etc...).
>
>Have you tried any such tool? Do you use any?
>
>I am in process of publishing an image compression benchmark and want
>to know what is in actual popular use and what all is only
>academically interesting.
>
>And if not, then why not? what do you think is missing in them that
>would make you change your mind?

I don't use them because disk space is so cheap that I don't want any
additional processing overhead.

--
Best regards,
John Navas
Panasonic DMC-FZ8 (and several others)
 >> Stay informed about: Do you use lossless JPEG recompression tools? 

On Fri, 18 Jan 2008 12:35:46 -0800 (PST), Sachin Garg
<schngrg.TakeThisOut@gmail.com> wrote in
<4b6dfbb7-625b-4e40-bf13-630fd8d97c1b.TakeThisOut@s13g2000prd.googlegroups.com>:

>On Jan 19, 12:17 am, John Navas <spamfilt....TakeThisOut@navasgroup.com> wrote:

>> I don't use them because disk space is so cheap that I don't want any
>> additional processing overhead.
>
>Yep, they are a bit slow. Around 12 seconds per 8 MegaPixel Jpeg on my
>Pentium4.
>
>Is it too slow even for backups?

Yes -- I like to be able to access my backups directly.

>Will your opinion change if it was,
>say, 1 sec per image?

It's not only the overhead, it's the hassle. What I'd rather have is an
alternative to JPEG that has the extra compression built-in.

--
Best regards,
John Navas
Panasonic DMC-FZ8 (and several others)
 >> Stay informed about: Do you use lossless JPEG recompression tools? 

"John Navas" <spamfilter1.DeleteThis@navasgroup.com> a écrit dans le message de news:
o142p3hcqsm9sd9g4ii6ag621n85vvs6uh.DeleteThis@4ax.com...
> On Fri, 18 Jan 2008 12:35:46 -0800 (PST), Sachin Garg
> <schngrg.DeleteThis@gmail.com> wrote in
> <4b6dfbb7-625b-4e40-bf13-630fd8d97c1b.DeleteThis@s13g2000prd.googlegroups.com>:
>
>>On Jan 19, 12:17 am, John Navas <spamfilt....DeleteThis@navasgroup.com> wrote:
>
>>> I don't use them because disk space is so cheap that I don't want any
>>> additional processing overhead.
>>
>>Yep, they are a bit slow. Around 12 seconds per 8 MegaPixel Jpeg on my
>>Pentium4.
>>
>>Is it too slow even for backups?
>
> Yes -- I like to be able to access my backups directly.
>
>>Will your opinion change if it was,
>>say, 1 sec per image?
>
> It's not only the overhead, it's the hassle. What I'd rather have is an
> alternative to JPEG that has the extra compression built-in.
>

Time for backups are not too important, I copy my files to another machine,
to a portable USB drive and I have just added a network drive (500Gb). Just
start a copy before going to bed and sleep over it. It is more important
for me to be able to read old files rather than rely on a piece of software
that may not be aroung or supported on a future processor or operating
system.

Jean
 >> Stay informed about: Do you use lossless JPEG recompression tools? 

On Jan 19, 1:49 am, John Navas <spamfilt....RemoveThis@navasgroup.com> wrote:
> On Fri, 18 Jan 2008 12:35:46 -0800 (PST), Sachin Garg
> <schn....RemoveThis@gmail.com> wrote in
> <4b6dfbb7-625b-4e40-bf13-630fd8d97....RemoveThis@s13g2000prd.googlegroups.com>:
>
> >On Jan 19, 12:17 am, John Navas <spamfilt....RemoveThis@navasgroup.com> wrote:
> >> I don't use them because disk space is so cheap that I don't want any
> >> additional processing overhead.
>
> >Yep, they are a bit slow. Around 12 seconds per 8 MegaPixel Jpeg on my
> >Pentium4.
>
> >Is it too slow even for backups?
>
> Yes -- I like to be able to access my backups directly.
>
> >Will your opinion change if it was,
> >say, 1 sec per image?
>
> It's not only the overhead, it's the hassle. What I'd rather have is an
> alternative to JPEG that has the extra compression built-in.

Yep, this makes sense.

Can I have any more opinions? Is anyone else here using these tools?

Sachin Garg [India]
www.sachingarg.com | www.c10n.info
 >> Stay informed about: Do you use lossless JPEG recompression tools? 

On Jan 19, 3:51 am, "jean" <try....DeleteThis@find.it> wrote:
> "John Navas" <spamfilt....DeleteThis@navasgroup.com> a écrit dans le message de news:
> o142p3hcqsm9sd9g4ii6ag621n85vvs....DeleteThis@4ax.com...
>
>
>
> > On Fri, 18 Jan 2008 12:35:46 -0800 (PST), Sachin Garg
> > <schn....DeleteThis@gmail.com> wrote in
> > <4b6dfbb7-625b-4e40-bf13-630fd8d97....DeleteThis@s13g2000prd.googlegroups.com>:
>
> >>On Jan 19, 12:17 am, John Navas <spamfilt....DeleteThis@navasgroup.com> wrote:
>
> >>> I don't use them because disk space is so cheap that I don't want any
> >>> additional processing overhead.
>
> >>Yep, they are a bit slow. Around 12 seconds per 8 MegaPixel Jpeg on my
> >>Pentium4.
>
> >>Is it too slow even for backups?
>
> > Yes -- I like to be able to access my backups directly.
>
> >>Will your opinion change if it was,
> >>say, 1 sec per image?
>
> > It's not only the overhead, it's the hassle. What I'd rather have is an
> > alternative to JPEG that has the extra compression built-in.
>
> Time for backups are not too important, I copy my files to another machine,
> to a portable USB drive and I have just added a network drive (500Gb). Just
> start a copy before going to bed and sleep over it. It is more important
> for me to be able to read old files rather than rely on a piece of software
> that may not be aroung or supported on a future processor or operating
> system.

This concern might be true for proprietary formats from unknown
companies, but is it really a concern when its an open-source solution
(or if its from a dependable company)?

Sachin Garg [India]
www.sachingarg.com | www.c10n.info
 >> Stay informed about: Do you use lossless JPEG recompression tools? 

On Fri, 18 Jan 2008 17:51:05 -0500, "jean" <try_to.TakeThisOut@find.it> wrote:

>Time for backups are not too important, I copy my files to another machine,
>to a portable USB drive and I have just added a network drive (500Gb). Just
>start a copy before going to bed and sleep over it.

Jean,

It is relatively easy to have a backup done automatically every night when
you are sleeping. The software I use is: http://www.smsync.com/ which I saw
recommended by a computer columnist (probably the one that is quoted on
their home page).

What I haven't done is to set it up to back up the most important files
nightly to one of my web sites, where I have spare storage.

Don <www.donwiss.com> (e-mail link at home page bottom).
 >> Stay informed about: Do you use lossless JPEG recompression tools? 

Sachin Garg wrote:
> There are a number of tools available which can do "lossless"
> compression of jpeg files, they get around 20-25% compression. There
> are both commercial/proprietary (StufIt) and free/open-source options
> (PackJPG, PAQ etc...).
>
> Have you tried any such tool? Do you use any?
>
> I am in process of publishing an image compression benchmark and want
> to know what is in actual popular use and what all is only
> academically interesting.
>
> And if not, then why not? what do you think is missing in them that
> would make you change your mind?
>
> Sachin Garg [India]
> www.sachingarg.com | www.c10n.info

JPEG and 'losless' are really mutually exclusive terms.
The whole idea of JPEG compression is to achieve high compression rates
(6:1 or better), by discarding information not required for satisfactory
image quality, and then applying a standard compression technique, such
as LZW with Huffman, to the result. Leaving out the lossy step results
in dramatically reduced compression. Not worth bothering with.
 >> Stay informed about: Do you use lossless JPEG recompression tools? 

On Jan 19, 12:57 pm, "David J Taylor" <david-tay....DeleteThis@blueyonder.not-
this-bit.nor-this-bit.co.uk> wrote:
> Sachin Garg wrote:
>
> []
>
> > Can I have any more opinions? Is anyone else here using these tools?
>
> Not using - never seen any need.

OK.

btw, similar tools are possible for RAW files too, which are much
bigger than jpegs. Will such a lossless compression tool for raw
files, with 20-25% compression, be more useful?

Sachin Garg [India]
www.sachingarg.com | www.c10n.info
 >> Stay informed about: Do you use lossless JPEG recompression tools? 

On Jan 19, 1:38 pm, Ron Hunter <rphun... DeleteThis @charter.net> wrote:
> Sachin Garg wrote:
> > There are a number of tools available which can do "lossless"
> > compression of jpeg files, they get around 20-25% compression. There
> > are both commercial/proprietary (StufIt) and free/open-source options
> > (PackJPG, PAQ etc...).
>
> > Have you tried any such tool? Do you use any?
>
> > I am in process of publishing an image compression benchmark and want
> > to know what is in actual popular use and what all is only
> > academically interesting.
>
> > And if not, then why not? what do you think is missing in them that
> > would make you change your mind?
>
> JPEG and 'losless' are really mutually exclusive terms.
> The whole idea of JPEG compression is to achieve high compression rates
> (6:1 or better), by discarding information not required for satisfactory
> image quality, and then applying a standard compression technique, such
> as LZW with Huffman, to the result. Leaving out the lossy step results
> in dramatically reduced compression. Not worth bothering with.

You are correct that JPEG is lossy. These tools apply further lossless
compression on jpeg files.

Think of it as something similar to using zip.

Sachin Garg [India]
www.sachingarg.com | www.c10n.info
 >> Stay informed about: Do you use lossless JPEG recompression tools? 

Sachin Garg wrote:
[]
> Can I have any more opinions? Is anyone else here using these tools?
>
> Sachin Garg [India]
> www.sachingarg.com | www.c10n.info

Not using - never seen any need.

David
 >> Stay informed about: Do you use lossless JPEG recompression tools? 

Sachin Garg wrote:
[]
> This concern might be true for proprietary formats from unknown
> companies, but is it really a concern when its an open-source solution
> (or if its from a dependable company)?

Any proprietary format is dubious - look at the difficulties in reading
old word-processor formats. Open-source can be the kiss-of-death for a
project, as the programmers loose interest and move onto something else.
Seen that happen time after time.

Stick to standard JPEG.

David
 >> Stay informed about: Do you use lossless JPEG recompression tools? 

On Jan 19, 8:57 pm, John Navas <spamfilt....TakeThisOut@navasgroup.com> wrote:
> On Sat, 19 Jan 2008 07:09:48 -0800 (PST), Sachin Garg
> <schn....TakeThisOut@gmail.com> wrote in
> <b73da4bf-2ec9-4ab6-b305-f27751d70....TakeThisOut@h11g2000prf.googlegroups.com>:
>
> >On Jan 19, 1:38 pm, Ron Hunter <rphun....TakeThisOut@charter.net> wrote:
> >> JPEG and 'losless' are really mutually exclusive terms.
> >> The whole idea of JPEG compression is to achieve high compression rates
> >> (6:1 or better), by discarding information not required for satisfactory
> >> image quality, and then applying a standard compression technique, such
> >> as LZW with Huffman, to the result. Leaving out the lossy step results
> >> in dramatically reduced compression. Not worth bothering with.
>
> >You are correct that JPEG is lossy. These tools apply further lossless
> >compression on jpeg files.
>
> >Think of it as something similar to using zip.
>
> I think his point is that lossy compression isn't a good choice for
> archival storage in the first place.

Ah, I thought he misunderstood what these tools do

But anyway, that mostly depends on what one wants more (quality and
ability to do good post-processing, or just small good-enough files)
and most of the time we just don't get the choice (most cameras do
jpeg only).

In general however, I agree that loss should be avoided wherever
possible.

Sachin Garg [India]
www.sachingarg.com | www.c10n.info
 >> Stay informed about: Do you use lossless JPEG recompression tools? 

On Jan 19, 8:55 pm, John Navas <spamfilt....RemoveThis@navasgroup.com> wrote:
> On Sat, 19 Jan 2008 07:05:41 -0800 (PST), Sachin Garg
> <schn....RemoveThis@gmail.com> wrote in
> <520fc4b1-a402-443d-b8ab-d257d02a6....RemoveThis@j20g2000hsi.googlegroups.com>:
>
> >On Jan 19, 12:57 pm, "David J Taylor" <david-tay....RemoveThis@blueyonder.not-
> >this-bit.nor-this-bit.co.uk> wrote:
> >> Sachin Garg wrote:
>
> >> []
>
> >> > Can I have any more opinions? Is anyone else here using these tools?
>
> >> Not using - never seen any need.
>
> >OK.
>
> >btw, similar tools are possible for RAW files too, which are much
> >bigger than jpegs. Will such a lossless compression tool for raw
> >files, with 20-25% compression, be more useful?
>
> RAW formats are proprietary to particular products, and thus unsuitable
> for archival storage. Adobe DNG is a better alternative that has
> compression built-in, probably not recompressible.

There are so many independent tools that support all these raw formats
that I don't think we need to worry too much about any particular
company stopping support for them.

About DNG, its a great format adobe has created but I don't use it
(yet) for two reasons. A) I can't convert my DNG's back to original
format, if needed (some tools don't support dng). B) If ever support
for my raw files disappears from planet, I can 'then' convert my
images to DNG, why do it now

Sachin Garg [India]
www.sachingarg.com | www.c10n.info
 >> Stay informed about: Do you use lossless JPEG recompression tools?