The image log captured on devices with cameras on specified event is not stored in the database but in a separate folder in the BioStar 2 directory. 

You can find it in the directory below: 

C:\Program Files\BioStar 2(x64)\imagelog 

* file size 10~11kb

Note: the folder will be created once a imagelog is generated. It is not present if no image logs have been created before. 

The reference to the log can be found in the AC DB event log table of t_lgyyyymm 

The filename in the imagelog folder is  based on the IMGLGUID which is made up of the DEVDT (log time) and a unique ID. 

For instance my image log here is 1518054815_1_272577

I can look up 15180504815 in DEVDT to find the log record. If I look at the IMGLGUID I can confirm the file name and confirm that this image refers to that specific event.