Creating thumbnails on the consumer level DiskStation NAS boxes by Synology is incredibly slow which makes indexing of large photo collections take forever to complete. It's much, much faster (days -> hours) to generate the thumbnails on your desktop computer over e.g. SMB using this small Python script.
python dsthumbgen.py --directory <path>
Example: python dsthumbgen.py --directory c:\photos
Subdirectories will always be processed.
The script needs the Pillow imaing library (https://pypi.python.org/pypi/Pillow/2.5.1) to be installed.
Given a file and folder structure like below:
c:\photos\001.jpg
c:\photos\dir1\002.jpg
...the utility will create the following:
c:\photos\eaDir_tmp\001.jpg\SYNOPHOTO_THUMB_XL.jpg
c:\photos\eaDir_tmp\001.jpg\SYNOPHOTO_THUMB_B.jpg
c:\photos\eaDir_tmp\001.jpg\SYNOPHOTO_THUMB_M.jpg
c:\photos\eaDir_tmp\001.jpg\SYNOPHOTO_THUMB_PREVIEW.jpg
c:\photos\eaDir_tmp\001.jpg\SYNOPHOTO_THUMB_S.jpg
c:\photos\dir1\eaDir_tmp\002.jpg\SYNOPHOTO_THUMB_XL.jpg
c:\photos\dir1\eaDir_tmp\002.jpg\SYNOPHOTO_THUMB_B.jpg
c:\photos\dir1\eaDir_tmp\002.jpg\SYNOPHOTO_THUMB_M.jpg
c:\photos\dir1\eaDir_tmp\002.jpg\SYNOPHOTO_THUMB_PREVIEW.jpg
c:\photos\dir1\eaDir_tmp\002.jpg\SYNOPHOTO_THUMB_S.jpg
eaDir_tmp is used as a temporary directory name as @ characters are not valid in file names on Windows. Therefore these folders must be renamed to @eaDir for PhotoStation to recognize them. This renaming process must be done via SSH to the DiskStation unless the volume is mounted by NFS. Useful commands:
# remove any existing thumbnail directories, dry-run check print out before running next command!
find /volume1/photos -type d -name '@eaDir' -exec echo '{}' \;
# remove any existing thumbnail directories
find /volume1/photos -type d -name '@eaDir' -exec rm -rf '{}' \;
# rename directories
find /volume1/photos -type d -name 'eaDir_tmp' -exec mv '{}' @eaDir \;