Entry point for vision process spawn

[dfarrell07]

The controller, when spawning the vision process, needs to point the process at a target function that will be run first and will accept the shared memory objects (currently a dict of lists and dicts). This new function should kick off all vision things, not require being called as main and not require creating a vision object.

[napratin]

We can have a vision.py module within qwe.vision sub-package, and a run() method in it along the lines of what has been created in Planner.py (a similar convention can be applied for all packages, i.e. a .py file by the same name with a run method). On a related note, I suggest promoting the contents of qwe.vision.cv to qwe.vision - one reason being that an OpenCV namespace is also called 'cv' which may introduce confusion. If anyone has any strong reasons not to, please notify here, otherwise I'll go ahead and make these changes.

[dfarrell07]

I'm not seeing that vision.py module - have you pushed it?

daniel:~/Robot/current/high-level/qwe/vision$ grep -rni "run" ./* ./cv/linedetection.py:127:# Run a LineDetector instance using pycv.main.main() ./cv/colorfilter.py:177:# Run a ColorFilter instance using main.main() ./cv/linewalking.py:35: # Run LineDetector for one iteration ./cv/linewalking.py:36: keepRunning, imageOut = self.detector.process(imageIn, timeNow) ./cv/linewalking.py:56: return keepRunning, imageOut ./cv/linewalking.py:70:# Run a LineWalker instance using pycv.main.main() ./cv/main.py:2:Driver program for running a FrameProcessor. ./cv/main.py:12: """Run a FrameProcessor on a static image (repeatedly) or on frames from a camera.""" ./cv/main.py:70: keepRunning, imageOut = processor.process(frame, timeNow) ./cv/main.py:73: if not keepRunning: ./cv/main.py:114:# Run main() function daniel:~/Robot/current/high-level/qwe/vision$ ls -R | grep -i vision daniel:~/Robot/current/high-level/qwe/vision$ git pull Already up-to-date. daniel:~/Robot/current/high-level/qwe/vision$

[dfarrell07]

I don't know of a good reason not to do the package refactoring that you described.

[dfarrell07]

I'm still not seeing the vision.py module or the run() function. Please go ahead and push it when you get a chance.

[dfarrell07]

Wow, sorry, just noticed the wording is "can have" - I thought you were saying that this code already existed, and I was just waiting on you to push. Sorry for the confusion!

[napratin]

Yes, sorry about that - I'm still working on it.

[napratin]

Code pushed; qwe.vision.vision.run() will be the entry point. Some modification may be required (replace context argument with bot_loc, blocks, etc.).

[dfarrell07]

I made the modifications you described above. Controller now spins up a vision process.

[napratin]

I noticed you commented out visManager.start() in vision.py -> run(). Was it not working properly? It should simply open an available camera and start the appropriate vision processors. I'm going to modify it to accept a single argument - filename for a static image or video, that should help in development.

[dfarrell07]

I think it was crashing when I commented that out, but it seems to be working perfectly now. I'll let you uncomment it, since you're making other changes and I don't want to cause you to have to deal with a manual merge.

[napratin]

I somehow feel it might be better to have each module's entry point be an instance of a subclass of multiprocessing.Process (overriding the run() method), than using a generic Process object and calling start(target=...). E.g. if vision.VisionManager inherited from Process, you could simply do:

pVision = VisionManager(bot_loc, waypoints, ...)
pVision.start()

The advantage (I hope) is you could then do something like pVision.stop() (I actually have that method, so you could try), or even pVision.deactivateProcessors() (that too!). Not to mention, share the entire pVision object (this would be especially beneficial for Navigator and SerialInterface). But I don't know how multiprocessing works - is it even possible to call methods of a Process instance while it is running? Thoughts?