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Lepton 1.2

Compress JPGs by 20% or more

by Mike Williams

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Based on 0 ratings
License: Open Source
Operating Systems: Windows 10, Windows 7 (32 bit), Windows 7 (64 bit), Windows 8
Languages: English
Software Cost: Free
Date Updated: 28 November 2016
Watchlist: Add download to my watchlist
Downloads To Date: 166
Developer: Dropbox
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Compress JPGs by 20% or more

Lepton is an open-sourced Dropbox technology for the lossless compression of JPEGs.

The program can compress JPG files by 20% or more, exporting the results in a LEP format (picture.jpg > picture.lep). Point the program at LEP files later and it restores the original JPG file, byte for byte.

The download is a single executable file which runs from the command line. The simplest option is to pass Lepton the file you'd like to process, and it's converted accordingly (JPGs are compressed to LEPs, LEPs are restored to JPGs).

The program doesn't make much effort to check its input. You might expect to run it like this...

lepton mypic.jpg

...but that gives you an error. You must include the ".exe", like this:

lepton.exe mypic.jpg

If you're including a file path with a space, be sure to surround it with quotes, or the program may crash.

lepton.exe "c:\my pics\mypic.jpg"

If that sounds like too much hassle, we've put together LeptonGUI, a very simple front end which accepts files by drag-and-drop. This doesn't have any other functionality, though, so if you're happy with command line testing then the main lepton.exe is all you need.


Lepton.exe delivered very impressive results for us, shrinking our test files by an average of more than 20%, and in a few cases achieving 50% or more.

We wouldn't like to trust it as our sole archiving tool, just in case a bug means some images aren't processed or restored correctly. It's interesting as a proof of concept, though, and if you've lots of images to archive it's certainly worth a look.

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Spotlight: Free Full Software

WhatsApp Messenger 2.18.51

Free Full Commercial Software

WhatsApp Messenger is the world's most popular instant messaging app for smartphones.

You can use it to send and receive text and voice messages, photos, videos, even call your friends in other countries, and because it uses your phone's internet connection it might not cost you anything at all (depending on whether you'll pay data charges).

It's easy to set up and use. There's no need to create and remember new account names or pins because it works with your phone number, and uses your regular address book to find and connect you with friends who use WhatsApp already.

You can talk one-to-one or in group chats, and because you're always logged in there's no way to miss messages. Even if your phone is turned off, WhatsApp will save your messages and display them as soon as you're back online.

There's plenty more (location sharing, contact exchange, message broadcasting) and the app is free for a year, currently $0.99/ year afterwards.

What's New in Version 2.18.51

• When you receive a link to an Instagram or Facebook video, you can now play it right within WhatsApp. With picture-in-picture, you can also keep watching the video while you navigate to another chat.
• If you're a group admin, you can now remove admin rights from other participants. Select the admin in "Group Info" and tap "Dismiss As Admin."
• Group admins can now choose who can change a group's subject, icon and description by going to "Group Info" and tapping "Group Settings."