Last Updated on July 22, 2020
Lepton with time chart
Earlier in this article, we confirmed that Guetzli runs slower than molasses. And MozJPEG is fairly nippy at encoding. So how does Lepton fare?
Here’s a chart showing the time taken by Lepton to compress a variety of images. Even the 36MP photograph took a mere 2.4 seconds.
The C-18MP entry is MozJPEG (cjpeg) tackling an 18MP image in 2.5 seconds. Lepton is more than 6 times quicker. Remembering that Guetzli took a whopping 1848 seconds, Lepton is 770 times quicker.
Pages in this article:
Page 1 – Introduction
Page 2 – Guetzli – Compression charts
Page 3 – Guetzli – Time chart
Page 4 – MozJPEG – Compression charts
Page 5 – MozJPEG – Time chart
Page 6 – Lepton – Compression charts
Page 7 – Lepton – Time chart
Page 8 – Summary
According to the tests I made some years ago to be able to store efficiently invoices and other enterprise documents scans into a document management software without artifacts, even on very small letters, tests that I also extended to web sites pictures processing, here is what I found :
using GIMP as the graphic manipulation program with a :
* progressive .jpg encoding for slow connections enabled,
* 4:4:4 Subsampling method,
* Floating-point for the DCT method,
* only exif data kept (no thumbnail or other orientation/dimensions system)
*** and the most important feature : image colors indexed into a 256 colors optimized palette,
the threshold not to cross to be absolutely sure there will be no artifacts in the final picture, nor color problems (except, of course, with gradations, that do not fit in this process) is : 65 %.
My 2¢