compressing files (almost same size as original)...?

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Level 2

328 points

compressing files (almost same size as original)...?

hello.

Anytime i have to compress a file, in order to quickly send it over email, i right click on the file that needs to be compressed, and then i choose "compress". I then get a zip file that is barely smaller than the original file (from 7.8MB to 7.2MB), which makes compression almost pointless.

So i figured that its just because i'm using the generic stock file compression application, whatever that is..... so i decided to download stuffit expander.

But i get the same result whether i compress it into a .zip file, or a .sitx file.

I'm so confused, but i'm sure this is something very simple. Am i misunderstanding the whole concept of what file compresison is?

I know that this is such an elementary question, but thanks for your time.

Any help would be appreciated.

thanks!!

MacBook Air, OS X Mountain Lion (10.8.1)

Posted on Feb 19, 2013 9:08 AM

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Answer 1

guitar guy Author

Level 2

328 points

Feb 19, 2013 11:01 AM in response to Michael Black

ah, ok. I totally understand.

I was trying to compress an mp3, which is already a compressed format.

Sorry for my lack of knowledge.

Yet, I will also be needing to compress scanned text documents in jpg format.

I assume i will have the same issue because jpgs are already compressed formatsas well?

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Answer 2

Feb 19, 2013 9:14 AM in response to guitar guy

Your Operating system is designed to save many files types in a specific way and they are already compresses to the maximum your OS can do. Even if you attempt to compress them, they do not compress more that the OS has already compressed them. For these types of file types, you would need a "compressing software" to compress them beyond what the OS is capable of doing.

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Answer 3

Feb 19, 2013 12:57 PM in response to guitar guy

Yes, image formats don't compress well at all. Compression works best with files with lots of redundant data, so you can get massive reduction in size with ASCII text files, but far less so with files like images, sound files, movie files and such. Just the nature of the files themselves.

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Answer 4

Nov 2, 2016 4:53 AM in response to guitar guy

"in order to quickly send it over email," I now automatically reach for a file transfer service, the best I have found is 'Wetransfer', just as quick as using email, and no anxieties about sending (for me) vast files via email. No delay time, recipient can download immediately. 2GB service is free! can't imagine what I would be sending that would need 200?

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Answer 5

Feb 19, 2013 9:16 AM in response to guitar guy

What type of files are these? Things like plain text are highly compressable, while binary files like images are often esseantially uncompressable.

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Answer 6

guitar guy Author

Level 2

328 points

Feb 19, 2013 1:51 PM in response to Michael Black

ok, thank you.

So, like Karen suggested, is there some kind of pro level software that will further compress these hard-to-compress files?

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