Shadowy Daisy

Shadowy Daisy
by damned-truths

Submit your Photo
Hall of Fame

Please participate in Meta
and help us grow.

Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Is there any way to losslessly export from Picasa? Even when there are no edits there are differences in exported files vs the original - when exported with automatic (ie, original) quality and original resolution.

$ diff 1-IMG_0412.JPG IMG_0412.JPG
Binary files 1-IMG_0412.JPG and IMG_0412.JPG differ

Manual copying is tiresome and defeats the purpose of using Picasa in the first place. If lossless export from Picasa isn't possible, any suggestions for a fast photo manager in Windows that doesn't do shady stuff like this?

share|improve this question
Are you sure that the actual image data is resaved in this case? It may simply be that metadata has changed, causing the binary to differ. – mattdm Mar 31 '14 at 14:15
With Jpegs Picasa stores metadata in the files itself so this is likely. – his Mar 31 '14 at 16:13
To verify this, if you are on Linux you can use 'jpegtran -copy none -outfile out.jpg in.jpg' to remove all metadata (otherwise lossless). Diff the files again and see what comes up. – mivilar Mar 31 '14 at 17:49
up vote 0 down vote accepted

In practice, it isn't really possible to use Picassa's "Export to Folder" losslessly.

This is because in fact the file isn't copied/moved but loaded and re-encoded with God-knows-what settings, besides of that 'Automatic - preserves original image quality'.

JPEG writing engine has much more settings than 'Quality': DCT method, Subsampling, Smoothing etc. See for yourself bellow:

JPEG engine

I searched enough time for the the program with the best (biggest number of actions/options/transformations) and fastest (yes, I did many benchmarks - I was forced to) Batch Processing engine as well as with the most flexible on-disk primitives (Copy/Move/Rename for many files selected on different criteria) and for me this is XnView MP (new version with many improvements and bugfixes is due soon).

It supports multi-selection, searching, filtering etc.

You can download it, is freeware. Of course YMMV.

Disclaimer: I'm not the developer of program, just an old user. Also, beware: the program is quite deep - there are forums to ask.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.