How do you increase compression?

T

Trackr

[H]ard|Gawd
Joined
Feb 10, 2011
Messages
1,786
I want to compress several GB of files into a single .rar, but every time I try, the compression rate is ~99%.

Isn't there a way to get it down to 50%, so that the file size is half?
 
That depends on the content. You're probably trying to compress files that are already compressed, like movies.
 
Well, no. Mostly JPEGs and text files.. but the text files don't take up too much room as it is.
 
JPG is already compressed to some degree. bmp, for example, is not compressed. Text files are not compressed.
 
So, there is no way to save more space with JPEGs? Because I really need a way to store them..
 
if you have 7zip you can try compressing using lzma or lzma2 but generally speaking you aren't going to get much (if any) extra compression on .jpeg's, it'd be similar to compressing .mp3's or x264 videos, they are already compressed.

You could rar/zip them up and throw them on an online backup site like mega or something if you are just low on hdd space.
 
No, I just have some important files that I want to back up for posterity and I'd like to limit the size.

I have it down to 25GB not compressed. I'm getting 22.5GB compressed, but that's not enough.
 
That's all you're going to get. Either resave the JPGs with lower quality or stick with what you have.
 
You could use irfanview to experiment with saving in different compressions. Once you find a method that gives you compression you want without IQ loss, do a batch conversion and leave it running over night. With hard drive space being cheap, I'd rather have the IQ than space on disk.
 
I'd rather not touch the JPEGs. If I can't compress them without losing quality, I'll have to leave it at 25GB.
 
Trackr said:
I thought PNG was much larger than JPEG.
Click to expand...
PNGs, JPGs, and GIFs each have their strengths.

JPGs really excel with low filesizes when it comes to actual photography.
PNGs really excel with low filesizes when it comes to digital images that are simple, such as desktop screenshots (where there is a very simple or no desktop wallpaper), screenshots of program windows, typical mspaint pictures (like FFFFU rage comics), webgraphics, etc.
GIFs can be animated, and seldom win against JPG and PNG in filesize; I can't remember what conditions an image must naturally fit to give GIF a chance at winning in filesize, but in webdevelopment sometimes it will win over PNG.

I have spent a significant amount of time and have much experience comparing JPGs, PNGs, and GIFs from helping out a friend at Google with some game-related projects in development. For the most part, it comes down to JPGs and PNGs, and in most scenarios JPGs will probably be the optimal choice.

*Regarding experience, when working on game and webdevelopment things, because I was so much curious, for quite some time I purposefully saved every single graphic in JPG, GIF, and PNG (each at the most optimal settings in Photoshop for maximum compression without noticeable loss of color or any technical loss at all; also utilized PNG Monster for PNGs, and tried multiple configurations of PNG resulting with 2 or 3 different PNGs for comparison in some scenarios).
 
If the images are in JPEG they have already lost a ton of quality.

Your camera takes the RAW image from the sensor, throws away 4/5 of the data, applies sharpening (loosing fine contrast), boosts color then writes the bastard image to the flash drive.

1 wedding for me is usually 30 GB.
 
staticlag said:
If the images are in JPEG they have already lost a ton of quality.

Your camera takes the RAW image from the sensor, throws away 4/5 of the data, applies sharpening (loosing fine contrast), boosts color then writes the bastard image to the flash drive.

1 wedding for me is usually 30 GB.
Click to expand...

When I got my T2i, all I shot was RAW. I bought a 64GB UltraII card for 350$.

But then, I started taking RAW+JPEG.. and when I looked at the results on my 3007WFP-HC.. I just couldn't tell the difference.

So, I'm sticking with JPEG.
 
You must log in or register to reply here.
Back
Top