Andor server save format change

[fanmingyu212]

Currently Andor server saves pictures in TSV format and scientific notation. Therefore, every 512 * 512 image uses 8 MB storage, so the images are slow to save/read.

Maybe the following changes could help to reduce the storage space and to improve organization:

• Add an option in andor_config.py that allows saving pictures to subfolders of the image saving directory. For example, if the default saving directory is "C:\images\", then enabling this option will save pictures to "C:\images\2018\02\21\".
• Add an option in andor_config.py to save data in different file format. Right now it is saving TSV in .csv files. This option specifies whether the file is going to be saved as tsv or csv. There could be another option to save the file in binary to save space and speed up reading/saving.
• For TSV or CSV files, save the data in integer format. Saving them as integers will greatly reduce the file size. It takes 25 chars to save one pixel now (ex. "4.820000000000000000e+02"). If we save the number in integer format, it takes 3-4 chars for one pixel on average (ex. "482"). For binary files, save the data in 16 bit uint probably provides enough range (0 - 65535).

Please let me know what you think about those possible changes.

[fanmingyu212]

I am working on these features on the branch: https://github.com/CampbellGroup/common/tree/mf/220_andor_server_saving_change. Please let me know if you have any comments or suggestions.