Usage: ./timelapse.sh [ lapse [<options>] | fetch | parse | purge ]
       lapse - processing image series
       fetch - get new image series
       parse - get image series and processing current period for all modes
       purge - remove old files

<options>
-mode [ split | mixed | blend | faded ]
  Current image processing mode. Use all modes by default.
-beg [ timestamp | datetime | delta[|s|m|h] ]
  Define start period. Use current time by default.
-end [ timestamp | datetime | delta[|s|m|h] ]
  Define end period. Use start period by default.

  timestamp - Unix timestamp (seconds since the epoch)
   datetime - date and time in format [YYYYMMDD]T[HHNN]
              use current date/time if ommited
      delta - time shift from current in format [+|-]num with suffix:
              no suffix - interval (range 0..9999)
              s - delta in seconds
              m - delta in minutes
              h - delta in hours

Examples:
* ./timelapse.sh fetch
  Get and save image series (without processing)
* ./timelapse.sh lapse -beg 4h
  Processing all modes for last 4 hours
* ./timelapse.sh lapse -beg 24h -end 6h
  Processing all modes for 6 hour interval of 24 hours ago
* ./timelapse.sh lapse -mode split -beg 20191101T -end 100
  Processing split-mode for interval from 2019-11-01 for 100 intervals
* ./timelapse.sh parse
  Get and processing image series