image_preparing event Leave feedback

Occurs when an image is going to be prepared for indexing.

extractor.image_preparing += handler    # subscribe handler(sender, args)
extractor.image_preparing -= handler    # remove the last subscription of handler
extractor.image_preparing.clear()       # remove every handler added from Python

The handler runs on the thread that raises the event, which can be an engine worker thread. An exception it raises there is printed to stderr and ignored; on the calling thread it reaches the engine, as in .NET.

• class Extractor