Request: A compression program

[Ragab]

Is there a compression program that can compress files to a very small size?
I mean I need a program that can make a 100MB file --> 50MB or less if
possible. I tried WinRar, WinZip, and KGB Archiver. But they r not effective.
Thanks for help

 

[R. McCarty]

Part of the issue is not the compression app, but the source file. Not
all files can be significantly reduced in size. Some formats such as Jpg
do not have much in the way of compressible data.

 

[Paul]

Is there a compression program that can compress files to a very small size?
I mean I need a program that can make a 100MB file --> 50MB or less if
possible. I tried WinRar, WinZip, and KGB Archiver. But they r not effective.
Thanks for help

http://en.wikipedia.org/wiki/Lossless_data_compression

"Limitations

Lossless data compression algorithms cannot guarantee compression for all
input data sets. In other words, for any (lossless) data compression algorithm,
there will be an input data set that does not get smaller when processed by
the algorithm."

At least some file formats, already use compression internally, making
it difficult for a compression program to "squeeze" out any more
bytes of data.

Paul

 

[Ragab]

Thanks for ur response
I need it to compress data files, like PDF and DOC files. Is there a
software can help?

 

[Ragab]

Thanks for ur response
I need it to compress data files, like PDF and DOC files. Is there a
software can help?

 

[R. McCarty]

Sorry, I'm not personally familiar with any compressors designed for
Pdf/Doc files. A web search turns up lots of hits for compressing those
file types - but nothing I recognized or would blindly recommend.

 

[Paul]

Thanks for ur response
I need it to compress data files, like PDF and DOC files. Is there a
software can help?

The only way to find out, is to test some new softwares.

PDF files vary in compressibility. Some files can be
compressed slightly, and some not at all. I would not
expect a 2:1 compression, but some smaller percentage
improvement in size. (The author of the PDF document, can
make a big difference to the compressibility. Specifically,
in the settings used in Distiller, for image compression.)

I'm not sure about DOC files. You would have to examine
them, with hex or text editors, and look for redundant
information in the file, to estimate whether it is
compressible.

Ordinary text files, on the other hand, should give good
compression.

Paul

 

[Ken Blake, MVP]

Is there a compression program that can compress files to a very small size?
I mean I need a program that can make a 100MB file --> 50MB or less if
possible. I tried WinRar, WinZip, and KGB Archiver. But they r not effective.
Thanks for help

How much a file *can* be compressed depends on what type of file it
is, as well as what data it contains. As a single simplistic example,
if there were a text file that consisted of nothing but the latter "x"
repeated 100 million times, it could easily be compressed to 15 bytes,
containing the characters "100 million x's".

In practice, of course, it's never that simple. Most files can't be
compressed anywhere near that much, and turning a 100MB file into 50MB
or less is almost never possible.

But bear in mind that it's primarily the file itself that determines
how much it can be compressed, not so much the program that's doing
the compressing. The programs you've tried do a good job of
compressing. If they can't do what you want (or at least very close to
it), it can't be done. You might find a program that did a *slightly*
better job, but that's all.

 

[HeyBub]

Is there a compression program that can compress files to a very
small size? I mean I need a program that can make a 100MB file -->
50MB or less if possible. I tried WinRar, WinZip, and KGB Archiver.
But they r not effective. Thanks for help

Compression is more dependent on the source document than on standard
compression programs. It is possible for a file to GROW as a result of
compression! (Experiment: Compress a file with RAR then apply ZIP to the
result. The ZIP file will be larger than the RAR file!).

PDFs compress fairly well; DOC files even more so. I doubt that either will
reach 50% very often.

You may have to investigate other techniques: Spanning the output file to
several media or just moving the changes to the file.

 

[Twayne]

Thanks for ur response

I need it to compress data files, like PDF and DOC files. Is there a
software can help?

It's not the program that determines how much a file can be compressed;
it's the file itself. Especially if it's an already compressed format.

If you've tried Winzip and a couple other name brands, those give you
the best you're going to get. You can set the compression to max, etc.,
in those, but ... beware ... other unzip programs may not be able to
unzip them since, like Winzip, has a proprietary compression algo that's
not supported by all the others.
An already compressed file can not be compressed further by more than
a few more bytes; it's not worth trying even.

HTH

 

[Patrick Keenan]

Is there a compression program that can compress files to a very small
size?
I mean I need a program that can make a 100MB file --> 50MB or less if
possible. I tried WinRar, WinZip, and KGB Archiver. But they r not
effective.
Thanks for help

If you find those apps to be "not very effective", even at the maximum
settings, you're not going to get where you want because your original file
can't be compressed to the point you want.

As everyone points out, compression utilities are only part of the equation.
The key is the kind of data in the document and the document format.

HTH
-pk

 

[Patrick Keenan]

Thanks for ur response
I need it to compress data files, like PDF and DOC files. Is there a
software can help?

Yes, and you've already tried them and found them inadequate.

That means that the problem is not with compression software, it means that
you've just reached the limit of compression for your particular files.

If you need them to be smaller, go back and look at those files and see if
you can edit them to reduce their size or density, or, split them in two.

HTH
-pk

 

[Ragab]

Thanks for all responses
Thanks for caring

 

[Phisherman]

Is there a compression program that can compress files to a very small size?
I mean I need a program that can make a 100MB file --> 50MB or less if
possible. I tried WinRar, WinZip, and KGB Archiver. But they r not effective.
Thanks for help

WinZip is pretty good. What kind of file are you trying to compress?
Perhaps you are trying to compress a file that is already compressed?

 

[M.I.5¾]

Is there a compression program that can compress files to a very small
size?
I mean I need a program that can make a 100MB file --> 50MB or less if
possible. I tried WinRar, WinZip, and KGB Archiver. But they r not
effective.
Thanks for help

You can use the best compression utility money can buy, but it won't
significantly commpress a file that is not inherantly compressable in the
first place. You don't say what you are trying to compress, but basically,
raw video files are generally the most compressible types of file with some
algorithms achieving almost unbelievable reduction ratios. Text is
inherantly very compressible. Most picture formats are hardly compressable
at all, mainly because the format already includes a compression algorithm.

 

[M.I.5¾]

How much a file *can* be compressed depends on what type of file it
is, as well as what data it contains. As a single simplistic example,
if there were a text file that consisted of nothing but the latter "x"
repeated 100 million times, it could easily be compressed to 15 bytes,
containing the characters "100 million x's".

And removal of that spurious possessive apostrophe would improve on that to
14 bytes.

 

[Ken Blake, MVP]

And removal of that spurious possessive apostrophe would improve on that to
14 bytes.

LOL! There's no question that the apostrophe is spurious. It's flat
out wrong. But it wasn't just a typo. I actually noticed it when I
wrote the message, deleted it, then decided that xs looked very
confusing. So I changed it to "x"s, and then changed it back, because
that made it 16 bytes.

Either way, I think my point was clear.

Ken

 

[3c273]

How about 7 bytes?
10e6(x)
Louis
</fun>

LOL! There's no question that the apostrophe is spurious. It's flat
out wrong. But it wasn't just a typo. I actually noticed it when I
wrote the message, deleted it, then decided that xs looked very
confusing. So I changed it to "x"s, and then changed it back, because
that made it 16 bytes.

Either way, I think my point was clear.

Ken

 

[Bill in Co.]

LOL! There's no question that the apostrophe is spurious. It's flat
out wrong. But it wasn't just a typo. I actually noticed it when I
wrote the message, deleted it, then decided that xs looked very
confusing. So I changed it to "x"s, and then changed it back, because
that made it 16 bytes.

Either way, I think my point was clear.

Ken

Actually, it depends on the algorithm used to contain that information, and
how its stored. And is the number being stored in real or integer format,
etc, etc.

So the actual length of the compressed file would be considerably more than
15 or 16 bytes, in reality. IOW, I'm pretty certain that when all is said
and done, the final result for the compressed text file would be a LOT
larger than 16 bytes, however.

 

[Ken Blake, MVP]

Actually, it depends on the algorithm used to contain that information, and
how its stored. And is the number being stored in real or integer format,
etc, etc.

So the actual length of the compressed file would be considerably more than
15 or 16 bytes, in reality. IOW, I'm pretty certain that when all is said
and done, the final result for the compressed text file would be a LOT
larger than 16 bytes, however.

Yes, it wasn't meant to be an actual algorithm that any existing
software actually uses, just an oversimplified example of one of the
kinds of thing that are done, and how dramatically a highly
repetitious file can be compressed.