zip

[moonlight burner]

Using winzip 8.o, 39 jpeg files of a total file size of 8.4MB zipped. Suprised to see the zip file to be 14.7 MB ! Strange isn't it ? Then why zip ????

moonlight burner

[Paul Victorey]

Well, this is because JPEG is, itself, a compressed format. Compressing an already compressed file yields very poor results, and often increases its size (as it has additional header info to store for each file).

Compressing something like a text file yields very good compression, or compressing an uncompressed image (like an RGB-encoded BMP file).

[Statica]

Thats the reason I've been favouring the ACE method of compressions of late. With ACE compression, I tried to duplicate as close a result as you got:
8.04MB - JPGs compressed down to 7.90 MB with ACE 2.xx
While on the surface it may not seem very much, as Paul remarked, JPGs are extremely difficult to shrink further.
Why ZIP indeed? They didnt even get there first .. Yoshi & LHA were actually around and more widely used before pkware, both for .lha's as well as for SFXs. The earliest version I remember using was for DOS 3.xx. I guess they arrived with the GUIs first on the scene, yet is puzzling why they are so widespread.

[Carl Price]

Originally posted by Statica
Why ZIP indeed? They didnt even get there first .. Yoshi & LHA were actually around and more widely used before pkware, both for .lha's as well as for SFXs. The earliest version I remember using was for DOS 3.xx. I guess they arrived with the GUIs first on the scene, yet is puzzling why they are so widespread.

Not true! Phil Katz came out with PKzip years before there was any other compression method other than arc. If fact zip came about because he had PKARC out and another company sued him claiming the format was theirs. Phil Katz goes clear back to dos 2.1 and maybe even earlier.

[WickedLittleSlaveBoy]

Statica has it, though....zip is an inefficient method of compression. it also compresses files on the file by file level...so, it can be less efficient because a file by file compression on compressed files wouldn't have much redundancy, but if you were to compress all the files together, you might get a good bit of compressable data. this is one of the reasons why gzip or bzip2 compressed tarballs tend to be smaller than zip compressed archives.

[audiyoda]

This agument is like Betamax v. VHS, DCC/DAT/minidisc v. cassette and so on. The better technology is nonexistent because of better marketing. Go figure.

AOL is the most expensive unlimited national ISP at $23.90, offers some of the worst browsing experiences on the net with their 'cache' servers, non-POP3 compliant mail servers, software full of bugs, and has endless busy signals and disconnects. But they have almost 10 million subscribers. Go figure.

ZIP is the worst at what it does, but it's also the most popular. Go figure.

-Craig

[Paul Victorey]

Well, ZIP is definately inefficient -- but it has its purposes. Nowadays, file compression is not as necessary, with huge hard drives and fast internet connections, a few hundred K aren't a whole lot.

ZIP files are still my preferred method of distributing a number of files; because it is popular, everyone can easily use a ZIP. Usually when I zip files, I care little for how compressed it is, and use ZIPs merely to put a group of files/directories into a single file.