OpenCV Haartraining does not finish forever

问题

This is the first time I use haartraining of opencv.

Just for practice, I used 35 positive images and 45 negative images.

But when I try to train from data, It does not finish forever,

Even when parameters are extremely adjusted.

(min hit rate = 0.001, max false alarm rate = 0.999

I don't think it would take a lot of time because of this extreme values)

What must be wrong in my experiment?

Here is my command and parameters.

$opencv_haartraining -data Training -vec samples.vec -bg negatives.dat -nstages 2 -nsplits     2 -minhitrate 0.001 -maxfalsealarm 0.999 -npos 30 -nneg 40 -w 20 -h 20 -nonsym -mem 512 -mode      ALL -minpos 10

And the result.

Data dir name: Training
Vec file name: samples.vec
BG  file name: negatives.dat, is a vecfile: no
Num pos: 30
Num neg: 40
Num stages: 2
Num splits: 2 (tree as weak classifier)
Mem: 512 MB
Symmetric: FALSE
Min hit rate: 0.001000
Max false alarm rate: 0.999000
Weight trimming: 0.950000
Equal weights: FALSE
Mode: ALL
Width: 20
Height: 20
Applied boosting algorithm: GAB
Error (valid only for Discrete and Real AdaBoost): misclass
Max number of splits in tree cascade: 0
Min number of positive samples per cluster: 10
Required leaf false alarm rate: 0.998001
Stage 0 loaded
Stage 1 loaded
Stage 2 loaded
Stage 3 loaded
Stage 4 loaded

Tree Classifier
Stage
+---+---+---+---+---+
|  0|  1|  2|  3|  4|
+---+---+---+---+---+

   0---1---2---3---4

Number of features used : 125199

Parent node: 4

*** 1 cluster ***
POS: 30 32 0.937500

回答1:

Am I correct in thinking that you are using OpenCV_Haartraining?

If so this is a deprecated app and you should use opencv_traincascades.

This will

- A. Speed up the time taken to classify 
 - B. Have better support

See these links for further reading Training Vs TrainCascade and TrainCascade Wiki.

EDIT:

also, change your min hit rate and maxFalseAlarm rate.

I would suggest using something like 0.4 & 0.95 to get going.

reason for this is that it will take forever for it to hit 0.999 & 0.0001 if ever.

回答2:

This is normal. Referring to this tutorial and my own experience, it's normal the training takes couple of days even up to a week. Quoting from the tutorial:

FYI: I recommend you to work haartrainig with something different concurrently because you have to wait so many days during training (it would possibly take one week). I typically experimented as 1. run haartraining on Friday 2. forget about it completely 3. see results on next Friday 4. run another haartraining (loop).

来源：https://stackoverflow.com/questions/16053378/opencv-haartraining-does-not-finish-forever