Compression makes files smaller in size.
0
votes
2answers
29 views
Good way to reduce number of colors in a PDF file?
I have pages of handwritten notes that I decided to scan to a PDF. Somehow, 153 pages of notes turned into a 156.4 MB PDF file.
The notes are scanned in color because I used four different colors: ...
0
votes
1answer
16 views
Is it possible to recursively list zip file contents with 7 zip without extracting
Similar to this question I have a very large zip file which contains other zip files, folders, and files. I want to use 7-zip to extract a list of file names from it, recursing into subfolders and zip ...
1
vote
3answers
43 views
Compressed (Zipped) Folders no longer extract properly
I actually just finished up cleaning a virus from my computer (took me in total like 20 minutes, no big deal), but I'm almost sure this is what caused the problem. Now, whenever I download a zipfile I ...
0
votes
3answers
45 views
powershell create zip from log files
How can I move log files to zip archives with System.IO.Compression.FileSystem in PowerShell?
I have more folders with log files per application:
app1logfolder
|-app1_20130507.log
...
3
votes
2answers
38 views
Is there a client impact to server side NTFS compression?
One of a our file servers at work is being compressed with NTFS compression. I've read about it being generally inadvisable on servers. But I've not found anything the states where the ...
0
votes
4answers
948 views
Word 2007 file too big
I have this novel I'm formatting. It has 37 images, most of them greyscale. They are all under 100 kb each. Most of them are under 50 kb. So I already know it's NOT the images. It's. Not. The. Images. ...
0
votes
0answers
12 views
mod_deflate - possible to compress 1k or higher only? cache?
Is there a way to tell mod_deflate in .htaccess to only compress files if they are at least 1kb? Also, can it cache compression results? Once it compresses a file, I want it to use that again instead ...
0
votes
2answers
31 views
When compressing a file on command prompt with RAR command, how to stop the process without cancelling it?
I used the following command:
rar a -m2 file.rar *.xml \\myroute\
I want to stop the process on the file that have already been processed i.e. using Ctrl + C will cancel the process but not finish ...
23
votes
4answers
15k views
How to specify level of compression when using tar -zcvf?
I gzip directories very often at work. What I normally do is
tar -zcvf file.tar.gz /path/to/directory
Is there a way to specify the compression level here? I want to use the best compression ...
2
votes
0answers
34 views
Difference between lzip, 7z and zipx [closed]
I would like to know what is the difference between the algorithms used in these three compression schemes. I found that all three of them are based on LZMA. But I would like to know what makes them ...
0
votes
0answers
21 views
Can't view files from within WinRar (Win7 x64)
I have an issue with WinRar (64 bit version) on Windows 7 (x64) that is similar to the one described in another open question on this website
Link to the same issue on this site (unanswered)
However, ...
0
votes
1answer
134 views
Programs to generate “random” data based on (broken) compression algorithms
Sometimes it's fun to look the results of deliberately broken decompression - you change compressed file a bit and decompress it. Resulting file is broken from a certain position, derailing data: ...
0
votes
2answers
70 views
What is the difference in various commands for compressing files in linux?
What are the commands for compressing files in linux and what are the difference between them? (for example: tar, gzip, rar).
I'm working on Linux Mint 11 and doing a script for compressing files. I ...
-1
votes
2answers
49 views
What compression algorithms are used by rar? [closed]
I am reading about many compression and archiving techniques.. I am not able to find the compression algorithms that are used by rar. Also I would like to know if rar compresses each file separately ...
-1
votes
0answers
18 views
What is Ppmd compression? [closed]
I have read that ppmd compression is used in 7z and zipx. I would like to know what exactly does it do and what files and also what type of files is it suitable for.
0
votes
1answer
57 views
How do I compress a 200MB MOD video file?
My grandpa sends me this huge 200MB video file and asks me to compress it. I bet that there are many ways I can do this. For instance, just guessing some ideas:
Use an online conversion tool ...
-1
votes
0answers
22 views
Créate a JFIF header for jpeg DATA compressed (AC DC coefficients) [closed]
i créate an algorithme for jpeg compression for color image with language MATLAB,
i used tables (for groupe jpeg) to code DC and AC elements, finally i have 6 binary vectors
vect_dc_r,
vect_dc_v,
...
6
votes
6answers
1k views
Is there a free way to compress a PDF?
I have several PDFs that are quite large (one is 80+ MB). Is there a free way to compress that PDF to a smaller size?
0
votes
2answers
925 views
How to make sure a .tar.gz file is valid and will uncompress correctly?
I have a few BIG .tar.gz files, and I want to make sure they will uncompress, but without actually doing it.
If the file opens on "Archive Manager" on Ubuntu, and I can view it contents there, does ...
5
votes
4answers
6k views
How can I achieve the best, standard ZIP compression?
I don't care how long it takes to compress, all I want to achieve is two things:
The absolute best possible compression ratio
Compatibility with standard readers, such as Windows and WinZip
So ...
2
votes
1answer
35 views
Does OS X Preview support saving PDF with JBIG2 compression?
I have a PDF file containing hundreds of BW scannings, that I created on Windows using lossy JBIG2 compression, resulting in a nice 8MB file.
I can open that file on OSX with Preview, but if I add ...
4
votes
4answers
383 views
How to decompress a .bz2 file
I have a file as: filename.bz2, but I can't figure out how to decompress it. I tried several methods, none of them seems work.
I have tried the command: tar xvjf filename.tar.bz2, but it didn't work ...
1
vote
1answer
60 views
Copying all the files of one extension into a folder
I have been trying to write a .bat program which will find all the files with a given extension, for example *.doc, and will put them into a rar archive.
I want all the files to be copied even if ...
0
votes
1answer
43 views
Can we save and resume winrar jobs?
I'm trying to zip a 87 GB folder into multiple volumes, 1 GB each.
WinRar is able to do that, however the entire job takes about 20 hours.
Is there anyway to save and resume the state of the WinRar ...
0
votes
1answer
90 views
Between xz, gzip, and bzip2, which compression algorithim is the most efficient?
Between xz, gzip, and bzip2, which compression algorithm gives the smallest file size and fastest speed when compressing fairly large tarballs?
0
votes
0answers
79 views
“extra bytes at beginning or within zipfile,” won't open file
I have an 8.3 gig zip containing tons of telescope observation data, but I can't extract no matter what I try. I've tried Archive Manager, unzip, and tried this guy's fix: ...
10
votes
5answers
4k views
Is there a way of replacing those ghastly 7-Zip default icons?
I like 7-Zip a lot - it's my compression utility of choice on Vista and XP. I have just one problem with it: it's butt ugly. I'm really kind of reluctant to install it on my fresh Windows 7 system ...
19
votes
5answers
608 views
Why doesn't Gzip compression eliminate duplicate chunks of data?
I just did a little experiment where I created a tar archive with duplicate files to see if it would be compressed, to my awe, it was not! Details follow (results indented for reading pleasure):
$ dd ...
1
vote
1answer
56 views
Does OS X support disk compression?
I am new to the Mac world.
As you may know, NTFS has options to "Compress this drive to save disk space" or "Compress contents to save disk space".
I want to know whether OS X supports this feature ...
10
votes
5answers
16k views
What is the maximum compression ratio of gzip?
What is the largest size a gzip (say 10kb for the sake of an example) can be decompressed to?
1
vote
2answers
90 views
gzip several files in different directories and copy to new directory
I'm working with several files that are located in different directories that I need to compress into individual .gz files. I also need to move the compressed files to a single directory while leaving ...
1
vote
2answers
6k views
Can I compress a RAR file again to reduce its size?
I had a 326 MB iso file that I compressed using WinRAR, with the best compression method. It got compressed to 144 MB.
I want to compress more and want it to be limited to something around 22 MB.
...
3
votes
1answer
1k views
mp3 compression MPEG1 vs MPEG2
I'm using CDex for converting wav to mp3, and want to ask you guys what version to use;
MPEG I has max of 320kbps
MPEG II has max of 160kbps
MPEG II.5 has max of 160kbps
I'm looking for a better ...
0
votes
3answers
54 views
What is the equivalent unix command to a Mac OSX “Compress” menu action?
When I right-click a file in Mac OSX and select "Compress 'File Name'", what is the equivalent bash or terminal command to get the same result?
Is it just gzip -9 /path/to/filename?
6
votes
9answers
11k views
Highest compression for files(for web transfer)?
Have seen some highly compressed files around.(for eg: i have seen 700mb of data compressed to around 30-50mb)
But how do you get such compressed files, I have tried using softwares like Winrar and ...
10
votes
3answers
2k views
Mac OS X not reporting directory sizes correctly?
In Finder, I've noticed that if I duplicate some .app files (in the Applications folder), Finder will show that the duplicate .app file is not the same size as the original. This file size ...
-1
votes
1answer
36 views
CSS compressor for Windows [closed]
Is there any Windows software that can compress (minify) CSS (and JavaScript) files?
If it could combine selected files then compress them into 1 file, it's a positive point. (something like WinLess ...
1
vote
0answers
80 views
Wear leveling, Compression and Journaling Filesystem for SD cards [closed]
I'm looking for the ideal filesystem to place in my SD card holding the root of the operating system.
The FS must support journaling in order to provide better data safeness; compression is also ...
3
votes
1answer
138 views
Create a .png with zopfli
I wanted to give zopfli a try since I have some static .png's that I am using on a website.
I see how I can create .gz and .deflate-files. But how can I create a png that can be displayed in FF, ...
2
votes
2answers
127 views
How can I compress an attachment in my Mailclient inside my inbox?
I got a lot of emails with uncompressed formats (like bmp, txt, ...) that I want to keep inside my IMAP-inbox, so I can access them from all my devices (Windows, Linux, ios, Android).
Those emails ...
0
votes
2answers
204 views
What if I checked the box “Compress this drive to save disk space” on an SSD?
I was wondering how it would effect an SSD if this was checked:
I was just curious whether it would save my SSD disk space?
3
votes
2answers
50 views
Compress Similar Files Efficiently
I frequently have the need to compress files that are very similar to each other.
Currently I use 7Zip, which compresses a 16GB file down to 1.2GB in about 35 minutes using 8 cores with Ultra ...
0
votes
0answers
163 views
How do I compress system files for which I have been denied access?
I need to compress some files in a folder, but my system denies me access from doing so.
Since they are system files, how can I compress these files without changing the permissions?
I'm looking for ...
1
vote
2answers
4k views
How can I compress .mov files to fit on DVD-Rs on Mac OS X?
I'm running Mac OS X 10.6 and have a few large .mov files (around 20-30GB each) that I would like to burn onto separate data DVD-Rs. The resolution of the videos is 960x540 and the duration ranges ...
0
votes
1answer
99 views
Split a folder of files into multiple zip files based on size or # of files
My problem is that the file uploader I'm working with will only allow a zip file with a size of 10mb or less. Unfortunately, I have thousands of files that need to be processed and I do this by ...
2
votes
1answer
112 views
Why is ZFS gzip-9 compression so much worse than actually using zip files?
I am working with some very large packet capture files (~150GB across 30 files) but because of how highly redundant packet captures are, these compress to ~7% (14.29x) of their originally file size ...
2
votes
2answers
154 views
How to zip multiple folders in 7zip?
I have a folder, lets say, MAIN. Inside this folder, there are many folders(say f1,f2,f2...) which has subfolders and files in them. Now I need to zip these folders(f1,f2,f3...) and their contents ...
6
votes
8answers
960 views
How to compress a huge amount of PNG images?
At work, on certain projects I have to manage a lot of images. Most of the time PNG files work the best for what I'm doing.
With such a huge amount of images, I've tried using PNG compression with ...
1
vote
1answer
65 views
Most space-efficient format for image with large dimensions but few colors?
Recently I have had to scale up the dimensions of a gif image by a factor of 2, this resulted in an increase of the file size by about 8 times. While this is not a complete surprise, I can't help but ...
1
vote
2answers
82 views
Software for lowering the colors in PNG-24 files
I am searching for a software that will allow me to reduce the number of colors for PNG-24 transparent (as in photoshop) files. Photoshop doesn't allow me any control over the amount of colors the PNG ...
