Updating jpeg files
While the degree of compression can be somewhat adjusted to find a balance between quality and size, a compression ratio of 10:1 is most typically used.
This usually achieves compression with a modicum of perceptible loss.
Features User Comments Supported File Types System Requirements Running Exif Tool Example Output Tag Names Explained Tag Groups Writing Information Writer Limitations Known Problems Security Issues Date/Time Shift Renaming Files Performance Exif Tool Library Additional Resources New Discoveries Acknowledgements License Donate Contact Me Exif Tool is a platform-independent Perl library plus a command-line application for reading, writing and editing meta information in a wide variety of files.
(You can get a good, free Perl interpreter from ) Everyone else (Mac, Unix, etc): Don't worry, you already have Perl installed.
Exif Tool is also available as a stand-alone Windows executable and a Macintosh OS X package: (Note that these versions contain the executable only, and do not include the HTML documentation or other files of the full distribution above.) "...
it is the mother of all EXIF utilities; the BFG of meta-data extraction; the Pan Galactic Gargle Blaster of EXIF tools ...
However, the thumbnail in Nautilus (currently in version 3.14.3) does not change/update after the modification.
I find this highly unusual and annoying as there are many files to be changed and it is hard to quickly tell which ones I have done and which one I have not.This thing will suck the last bit of metadata out of whatever image file you throw at it!