Compressing files

[willie45]

Hi

Can someone tell me what I am doing wrong? When I try to compress a file which has for example, an original file of 500kb I will get a compressed one of around 489kb which doesn't seem very useful to me.

All advice gratefully received

Willie

 

[mathcolo]

Hi

Can someone tell me what I am doing wrong? When I try to compress a file which has for example, an original file of 500kb I will get a compressed one of around 489kb which doesn't seem very useful to me.

All advice gratefully received

Willie

Unfortunately the ZIP compression in Mac OS X isn't really... compression. You might have to use a third-party utility, of which there aren't very many at all.

 

[MisterMe]

Unfortunately the ZIP compression in Mac OS X isn't really... compression. ...

Not true. My guess is that the OP is trying to compress a video or graphics file that is already compressed.

 

[willie45]

I was trying to send a file of jpeg pictures, but I have also found this with PDF documents as well

Willie

 

[Nermal]

JPEG and PDF files are already compressed.

 

[richard.mac]

I was trying to send a file of jpeg pictures, but I have also found this with PDF documents as well

Willie

also 500kb these days is pretty small for the internets we have today.

 

[sammich]

Compression makes it easier to send multiple files across the net, regardless of the size. In any case, compression works the best on text based files, like word documents.

Paid for programs will do the job better, if you need it.

 

[gusious]

Hi

Can someone tell me what I am doing wrong? When I try to compress a file which has for example, an original file of 500kb I will get a compressed one of around 489kb which doesn't seem very useful to me.

All advice gratefully received

Willie

500kb are pretty small!! How small do you want to make them? Compression stops after a while. I mean you can't compress a file to 1kb!

 

[mysterytramp]

You might have to use a third-party utility, of which there aren't very many at all.

OS X out of the box does a pretty good job with ZIP files. (OK, I'll give props to Windows. Treating ZIPs as directories is not too shabby.) I've been using Zipeg lately because you can view a ZIP before it gets decompressed. And best of all, it's free. It has worked great on my machine (intel Mini, 10.4.11)

mt

 

[econoline06]

Not true. My guess is that the OP is trying to compress a video or graphics file that is already compressed.

Nice "guess" but he's right. I've tried on several occasions to use the zip utility in OS 10 without luck. It comes out exactly the same size or 2-4kb smaller. I have tried with files up to 1GB!

 

[mysterytramp]

Nice "guess" but he's right. I've tried on several occasions to use the zip utility in OS 10 without luck. It comes out exactly the same size or 2-4kb smaller. I have tried with files up to 1GB!

Lots of files have built in compression. .docx, pdfs, graphics files, audio files, etc., which means OS level zip-ping won't have much effect. And if you're compressing a file smaller than the block size on your hard disk, the compression won't mean much -- the physical size will be smaller, but the logical size will be the same.

I just did a quick test with the three largest text files on my hard disk. The compression was more than adequate.

mt

 

[themoonisdown09]

OS X out of the box does a pretty good job with ZIP files. (OK, I'll give props to Windows. Treating ZIPs as directories is not too shabby.) I've been using Zipeg lately because you can view a ZIP before it gets decompressed. And best of all, it's free. It has worked great on my machine (intel Mini, 10.4.11)

mt

I use Zipeg on my Windows computer at work. I use this instead of WinZip because WinZip gives you those annoying "Purchase Me" messages every time you use it.

 

[MisterMe]

Nice "guess" but he's right. ...

The OP is trying to compress graphics files just as I had guessed. As for MacOS X's built-in Zip compression, it substantially compresses files that are compressible.