Export with MozJPEG

Allows exporting as JPEG using the MozJPEG toolkit (https://github.com/mozilla/mozjpeg). MozJPEG provides better JPEG quality at the same file size. MozJPEG is promoted by Mozilla as an alternative to the Google's WebP format.

As to whether it does worth the fuss or not, you decide. I have made a comparison of all the today's battling web image formats: http://www.efenstor.net/web_image_format_comparison_2015.html

IMPORTANT!!!

You must edit the "cjpeg_path" variable in the plug-in file to point it to your cjpeg executable location. This plugin requires the "cjpeg" utility from the mozjpeg toolkit!

INSTALLATION

Linux:
1. cp export_mozjpeg.py ~/.gimp-2.8/plug-ins
2. chmod +x export_mozjpeg.py

Windows:
1. Remove Windows
2. Install Linux

USAGE

Method 1 (preferred):
1. File > Export As...
2. Enter the output file name but specify .moz as extension instead of .jpg
3. The resulting file will still be called .jpg
NOTE: if the output file already exists it is overwritten without warning!

Method 2:
1. File > Export As...
2. Open the "Select file type" list below
3. Select "JPEG image (MozJPEG toolkit)
4. On the "Extension mismatch" warning click "Save"

Method 3:
Rename/remove the original JPEG plugin (file-jpeg).
Linux:
1. cd /usr/lib/gimp/2.0/plug-ins
2. sudo mv file-jpeg .file-jpeg
Windows:
1. Remove Windows
2. Install Linux

DOWNLOAD
Mirror 1: https://yadi.sk/d/sU_7hSrckNGMR
Mirror 2: http://www.mediafire.com/view/1f91c23o9im6rh1/export_mozjpeg.py

NOTE: As mozjpeg is still not readily available at the repositories of the most of Linux distributions, I strongly recommend you to compile it from the source. Still, as it is not an easy task for a non-programmer, and if you trust me (although I discourage this approach), you can use the unofficial 64-bit binaries I have compiled myself (I cannot guarantee them to work on every Linux system): http://www.mediafire.com/download/h3c1wzgogdzucnw/mozjpeg_x86_64_git1511...

HISTORY
v0.31 - Disabled arithmetic coding by default as it may be incompatible with browsers/viewers using libjpeg for JPEG decoding (yet it gives better quality)
v0.3 - More options added and minor fixes
v0.2 - Added the DCT coding options
v0.1 - Initial release