|TAR.GZ File Compression for Windows|
File compression is a nice way to reduce the amount of disk space required to store data; it works by reducing the redundancy in data. Most text and html files compress well, since they use some characters more commonly than others (for example the letter 'e' is much more common in English text than 'z'), and contain many words and phrases used more than once. Other file types (for example, MRI images) have less redundancy and regularity, so they are more difficult to compress.
Most Windows users compress files into ZIP format, while Linux and other Unix users prefer GZ (for single files) and TAR.GZ (for collections of files; the extension .TGZ is also used for these). Most of the free compression tools for Windows will decompress GZ and TAR.GZ files; however, creating GZ files is not a common feature. My ezGZ program (shift+click to download program and source code) is a simple drag and drop GZ/TAR.GZ compressor and decompressor. If you drop a file with the extension '.GZ', ezGZ will decompress the file; if you drop any other file on the program, it will create a new, compressed file with the GZ extension (e.g. 'filename.ext' will be saved as 'filename.ext.gz'). You have the option of setting the compression level between 1 (fast, but little compression) to 9 (slow, but optimal compression).Usually, a value of about 6 is fine.
It should be pointed out that the GZ format only stores one file, whilst the ZIP format can store multiple files. So, to compress collections of files, UNIX users first combine them using the 'tar' program, and then run 'gzip' on the .TAR file that produces. These tar+gzipped files are usually denoted with the extension '.TAR.GZ' or 'TGZ'. If you drop multiple files onto my program, it will give you the option to create a single '.TAR.GZ' file that stores a compressed copy of all the source files. Likewise, if you drag and drop any file with the extension '.TAR', '.TGZ' or '.TAR.GZ', ezGZ will decompress it.