Added Haar cascade for russian cars licence plate detection

[alexstadnik]

Cascade works pretty fast, stump based, 16 stages overall.

[adrians]

I'm curious how does this compare to #2752 in terms of accuracy and performance.

Also, as a pro-tip: don't submit modifications inside your local "master" branch, because it'll go out of sync pretty fast. Try to work in another branch and submit a pull-request with that. This way, if you want to work on another patch you can branch again from your local master (sync'd with the upstream one), and not induce patch-dependencies in the new pull-request.

[alexstadnik]

Hi!
In terms of performance, this one has less stages, so it definitely runs a bit faster. According to standart example:
results for cascade from #2752:
Processing 1 --cascade=haarcascade_russian_plate_number.xml
Processing 2 vlcsnap-2013-08-12-15h53m18s33.png
detection time = 298.194 ms
//
Processing 1 --cascade=haarcascade_russian_plate_number.xml
Processing 3 vlcsnap-2013-08-12-15h54m12s17.png
detection time = 279.121 ms
/////////
results for given cascade:
Processing 1 --cascade=haarcascade_pltzzz64x16_16STG.xml
Processing 2 vlcsnap-2013-08-12-15h53m18s33.png
detection time = 172.356 ms
//
Processing 1 --cascade=haarcascade_pltzzz64x16_16STG.xml
Processing 3 vlcsnap-2013-08-12-15h54m12s17.png
detection time = 174.658 ms
//////
As for accuracy, this matter a bit more complex: #2752
#2752 detects more plates, but it gives more false detections also. For scientific comparison ROC-curve should be presented, but its a lot of work to do.

My commit was initiated by #2752, as an alternative, the same way as now we have few cascades in library for face detection.

I'm attaching results of both cascades for 2 images, to clearify a bit accuracy of detection.

Thanks for the pro-tip, I've made a branch, should I recommit cascade from new branch if you approve?

Sincerely.

detection results for given cascade:

detection results for cascade from #2752:

P.S.
Cascade from #2752 doesn't load by cvLoadHaarClassifierCascade in v.2.4.6, but I'm not sure is this a real thing.

[vpisarev]

great, thank you! 👍 (hopefully, I won't start receiving more speeding tickets sometimes soon :) )