Cascade Classifier Custom Feature Evaluator

asked 2016-11-08 10:15:51 -0600

cmrigney gravatar image

I would like to implement my own Feature Evaluator like the ones in cascadedetect.cpp and .hpp. But I'm not sure how they work. Can anybody explain it to me? It seems like the end result of an evaluation goes through the calc methods but I'm not sure what the values mean. I understand the principle behind cascade adaboost (and HAAR features), I just am confused on how the code works. Thanks.

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In principle you will have to

  • Build a new training tool
  • Build an extra detection interface

This can be done by

  • Making sure that for each window, a new set of features is generated
  • Expand the boosting process to be able to evaluate those features over the training set so it can select the strongest one
  • Make sure that during the detection, the runAt function is able to run the new feature evaluator

IT might sound simple, but I am afraid you are opening a wasps nest! xD Good luck!

StevenPuttemans gravatar imageStevenPuttemans ( 2016-11-09 04:41:21 -0600 )edit

Thanks for the comment! How exactly is the runAt result used? Along those same lines, what is predictCategorical, predictOrdered, etc, expecting from the featureEvaluator? How does that all fit?

cmrigney gravatar imagecmrigney ( 2016-11-09 14:25:55 -0600 )edit

runAt is basically used during the detection phase, not the training. It is called when the image pyramid is generated and the sliding window is running, on each specific window that it get and returns you the decision whether or not the window is an object or not. There is no way I can clarify the whole sourcecode parameter at a time, it would take me ages. But if you grasp the concept of cascade classifiers, the code is quite logical to follow.

StevenPuttemans gravatar imageStevenPuttemans ( 2016-11-10 02:18:15 -0600 )edit
1

Great thanks!

cmrigney gravatar imagecmrigney ( 2016-11-10 07:20:40 -0600 )edit

You welcome!

StevenPuttemans gravatar imageStevenPuttemans ( 2016-11-10 08:21:46 -0600 )edit
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