WinLep

The Lepton compression format developed by Dropbox can be used to reduce the size of existing JPG images by a significant amount, without any quality loss.
WinLep is a lightweight application that enables you to take advantage of this algorithm and compress one or more images in an efficient manner, as well as decompress existing LEP files. It is easy to use and features a modern, streamlined UI.

Fast image compression tool that yields great results

The Lepton open source algorithm is capable of compressing images at 5 MB/s and decompressing them at 15 MB/s, so you should be able to get through large albums in no time at all.
On average, a 22% size reduction is what you can expect when using this application, and the quality of the source images is not affected in any way. The created LEP files can be decompressed at any time should you wish to have your original JPG images back.

Intuitive software solution that can be used by experts and novices alike

WinLep is remarkably easy to use, whether you need to convert a single file or every image stored in a particular folder. The application offers support for drag and drop, so you can import items with very little effort.
Additionally, it is possible to select a certain directory and have the program process every JPG or LEP file within it automatically. You can specify whether or not subfolders should be included, and the program can delete the original files when the job is completed.

Handy converter that can also function as an image viewer

WinLep offers a set of basic navigation tools, making it possible to cycle through the pictures stored in a particular folder, zoom in our out and copy items to the clipboard. Given that some applications may not support the generated LEP files, is certainly helps to have a convenient way to view them.
Overall, this is a great solution for users who wish to take advantage of the Lepton compression algorithm in order to reduce the file size of their images. It features a well-designed user interface, and it enables you to compress or decompress large numbers of JPG or LEP files at once.