jpg pictures compression files
Jan Schmidt
probabbly this is an old and often discribed question,
perhaps i didn't use the best keys to search, but i coun't find an answer by
myself.
i hope for your help.
i have got some pictures, most of them are .jpg files.
and i want to pack and compress them to one archive.
I tried rar zip and some others, but the results ratio is rather poor.
So, what kind of compression type is the best to handle pictures like .jpg
files?`
regards
Jan
Thomas Richter
Jpeg files are already compressed, you cannot compress them much further.
Some recent "transcoder" approaches can gain around 10-20%, but that's
about it. See some older posts on this forum to find out.
So long,
Thomas
Sportman
> So, what kind of compression type is the best to handle pictures like .jpg
> files?
http://www.stuffit.com
Some results:
http://compression.ca/act/act-jpeg.html
http://www.maximumcompression.com/data/jpg.php
Flavius Vespasianus
news:42bbfd08$0$1132$9b4e...@newsread4.arcor-online.net:
> So, what kind of compression type is the best to handle pictures like
> .jpg files?`
None.
Data that is efficiently compressed does not lend itself to compression
again.
Assume for the moment that you have a compression technique f(x) that never
produced negative compression. You could simply do
f (f(x))
repeatedly until you had one byte and a count of times you did f(x).
It simply doesn't happen.
Darryl Lovato
bQ4ve.11170$pa3....@newsread2.news.atl.earthlink.net, "Flavius Vespasianus"
<n...@nl.com> wrote:
> "Jan Schmidt" <his...@gmx.net> wrote in
> news:42bbfd08$0$1132$9b4e...@newsread4.arcor-online.net:
>
>> So, what kind of compression type is the best to handle pictures like
>> .jpg files?`
>
> None.
Except StuffIt of course - which gets approx 30% on existing jpeg files with
no additional loss.
> Data that is efficiently compressed does not lend itself to compression
> again.
>
> Assume for the moment that you have a compression technique f(x) that never
> produced negative compression. You could simply do
>
> f (f(x))
>
> repeatedly until you had one byte and a count of times you did f(x).
>
> It simply doesn't happen.
Correct. But that's not what StuffIt does. It only works one time - not
recursive.
- Darryl
Jan Schmidt
"Sportman"
> Stuffit do the job, but not for free:
> http://www.stuffit.com
>
> Some results:
> http://compression.ca/act/act-jpeg.html
> http://www.maximumcompression.com/data/jpg.php
how to get a trial version without having a credit card and will to contact the
company?
i mean, i tried to download from original webside, but it was not allowed
without entering the credit card number...
why isn't it posible to try this version, before i buy it?
Can someone tell me a place where to load?
thanks, i really wnat to try it firstl
Sportman
> how to get a trial version without having a credit card and will to contact the
> company?
>
> i mean, i tried to download from original webside, but it was not allowed
> without entering the credit card number...
> why isn't it posible to try this version, before i buy it?
>
> Can someone tell me a place where to load?
>
> thanks, i really wnat to try it firstl
You can try this Windows trail version:
http://www.allume.com/downloads/files/StuffItStandard9.exe
Claudio Grondi
> http://www.allume.com/downloads/files/StuffItStandard9.exe
Jan Schmidt, please report details of your evaluation,
because there are some serious doubts if Stuffit can what
it pretends to. Compression depends much on the
kind of data, so it will be interesting to know about
your special experience.
Please consider also some jpg optimization software
you can play with the compression level around to have
a good base for a not only to Stuffit limited evaluation:
Understanding JPEG compression:
http://www.photo.net/learn/jpeg/
http://www.imaging.org/resources/jpegtutorial/index.cfm
jpgQ - JPEG Quality Estimator (can tell with which quality the
genuine picture was saved as JPEG):
http://www.mediachance.com/digicam/jpgq.htm
http://www.mediachance.com/digicam/JpgQ.zip
and other graphic tools:
http://www.mediachance.com/digicam/index.html
JPEG Wizard is the ultimate JPEG image editing and compression tool
providing even details about the computer system hardware and software.
All it does to achieve better compression is convert the huffman entropy
coding to arithmetic coding, or the reverse to go back to baseline JPEG.
The only restriction of the downloaded trial version is a watermark in
the center of saved images. It allows to watch in real time the impact of
the choosen picture quality level:
http://www.pegasusimaging.com/jpegwizard.htm
ftp://www.pegasusimaging.com/pub/jpgwizard/JPGWIZ.EXE
Claudio
"Sportman" <spor...@gmail.com> schrieb im Newsbeitrag
news:1119725688....@g43g2000cwa.googlegroups.com...
Chris Johnson
>>You can try this Windows trail version:
>>http://www.allume.com/downloads/files/StuffItStandard9.exe
>
> Jan Schmidt, please report details of your evaluation,
> because there are some serious doubts if Stuffit can what
> it pretends to. Compression depends much on the
I bought Stuffit v9 Deluxe and it does in fact compress JPEGs just as it
claims ("pretends"!?) to. My typical compression rate is 20-25%. Not a
huge saving, but better than 1-3%.
This other time, at band camp, Flavius Vespasianus wrote:
> "Jan Schmidt" <his...@gmx.net> wrote in
> news:42bbfd08$0$1132$9b4e...@newsread4.arcor-online.net:
>
>
>>So, what kind of compression type is the best to handle pictures like
>>.jpg files?`
>
> None.
>
> Data that is efficiently compressed does not lend itself to
> compression again.
Actually, even data that's been ineffienctly compressed does not lend
itself to compression again and this is the fact that Stuffit works off
of. By undoing the last stage of lossless compression in the JPEG
standard and re-compressing with a much more effient routine it is able
to perform this trick.
Impressively, Stuffit stores enough information about the original file
to recreate an exact bit-for-bit copy of it. Personally, so long as it
can restore to the exact same picture (with the EXIF information), I'd
be happy to save a little extra space at the cost of the original file.
Maybe next version.
Chris J.