Anshul's profile - activity

I was trying to ask new question "Featur tag is missing in cascade.xml using opencv_traincascade" but forum is pointing me over here!! <br>

I created the cascade successfully, but I was wondering that in xml file there is no feature tag in my xml file, are they generated automatically by opencv_traincascade or we have to write some extra code for that, In my case i have only used opencv_traincascade and created very ugly cascade.

Similar problem as you have, do we have to create feature explicitly,aren't the auto generated when using opencv_traincascade

thats ok,

as you were in same problem, thinking that you positives are bed. size?? as you had picture 100x200 you asked what size in vec-file will be most appropriate? 10x20?

what size should i prefer if i have 720x1280 and vounded object of 1100x400(avg).

I was following http://note.sonots.com/SciSoftware/haartraining.html#n4ea83fa there is subtopic create sample from some

If I am not passing any argument to create_sample "opencv_createsamples -num 1201 -vec imgs/vector.vec -info info.txt -w 64 -h 32" then opencv take some default value

Info file name: info.txt Img file name: (NULL) Vec file name: imgs/vector.vec BG file name: (NULL) Num: 1201 BG color: 0 BG threshold: 80 Invert: FALSE Max intensity deviation: 40 Max x angle: 1.1 Max y angle: 1.1 Max z angle: 0.5 Show samples: FALSE Width: 64 Height: 32 Create training samples from images collection... Corrupt JPEG data: premature end of data segment Done. Created 1201 samples [

hi steven

Dont take me negative. I have already posted in your question, that i an training cascade on low resolution (24x24 or 64x32 still dont know exact value)), high resolution was used to test (manually by eyes) that whether the dimension of object(info.txt) in sample are correct or not. just for verifying the vector file

you took it wrong, i have 1203 all original image, i manually detected where is the object (x,y,h,w) in image and then bundled those images using opencv_createsamples , below is the command. opencv_createsamples -num 1201 -bg negative/negative.txt -vec imgs/vector.vec -info info.txt -maxxangle 0.1 -maxyangle 0.1 -maxzangle 0.1-maxidev 100 -bgcolor 255 -bgthresh 0 -w 64 -h 32

i have around 1100 image of 1280x1080 and 100 of random size, if i scale them by 4 , it would stilll be lot more so i have scaled them lot (24x24). just now i am trying to make train cascade 64x32 (to train cascade it take more than 18 hour on i3 pc)

that was my first day using opencv, to verify that whether i have given the dimension of object properly or not it is better to go with high resolution, but when creating sample for cascade training i go for some small resolution.

as you said "Next - if there are false alarm, my positives are bad? Size - if e.g. I have picture 100x200 what size in vec-file will be most appropriate? 10x20? How to calculate minHitRate? There says - samples must be unique. If samples are from one picture it bad? Why? They also will be unique in one object. If I created many samples from many objects, how can I pack them in vec-file?"

(assuming false alarm as false detection of object) I have lot of false alarm when i set maxfalseAlarmRatio to 0.9 or 0.5 in case of 0.09 i cant detect my object. i have my actual phototograph of 1280x720 and object dimension ratio 1100x400 (avg). what size in vec-file will be most appropriate??

Please let me know if you got answer, meanwhile i am searching for it.

hi Steven

I have some similar question on maxFalseAlarmRate

maxFalseAlarmRate as you answered MaximumFalseAlarmRate gives you the rate that needs to be achieved on your negative count. You will always end up with NEG amount:number number is false object detection in those negative picture, is it number of picture where object is found, or number of object in one picture, or sum of both.

By Prasanna-

You can open your "negative.dat" file in a text editor. As for verifying a vec file, Use the opencv_createsamples.exe by passing vec file, width and height as arguments and -show option. (For example, opencv_createsamples.exe -vec imgs/vector.vec -w 640 -h 480 -show). But why are you using such high resolution like 640x480? It will take ages to train.

Theres a waitKey(0) between showing samples from a vec file. Hit the enter key to go ahead. Make sure you merge the vecs created for each image.

Steve and Prasanna

Sorry for too late reply, busy in collecting positive sample.

Actually i was trying with lot of images and there are some image of different dimension. I have 1200 positive samples and in those 1000 are of 1280x720(taken out from my own camera) and 100 are of random size(downloaded from internet google image) so what would be the right choice height and width ???

I don't Know What is wrong, but my cascade still does not detect object well.

Ok I will try 64x48, just now i am working with 24x24, 640x480 was some random number My Assumption that why we are taking small size is, that we can recognize the image even at that small size so why to take large size image when they will fill ur ram.

I solved the error "Image reader can not be created from -vec vector.vec and -bg bkg.dat" it was because of silly typo i spelled the negative.dat as negatve.dat" sorry for posting silly error but that error gave me no hint that file does not exist or some ting like that

Got that ! Why dont you put ur both comment as answer, for me they were answer to my question. Thanks lot

what should be width and height while training cascade.

I was trying to train cascade using opencv_traincascade binary, I am using linux 3.7, I threw the below command,

opencv_traincascade -data imgs/cascade/ -numPos 200 -numNeg 8 -numStages 10 -featureType LBP -maxFalseAlarmRate 0.9 -w 640 -h 480 -vec imgs/vector.vec -bg negatve.dat

but it is giving me error "Image reader can not be created from -vec imgs/vector.vec and -bg negatve.dat."

I read that link, and improved lot of things. but while verifying the vect file by show argument does not work for me, It shows me only first sample, not all sample. if i press esc at the windows no other window appear and program exit. if i press x at right upper corner of window than window close and create sample utilitiy get hang. if this is normal behaviour than i want to see all the sample created and stored in vct file. do you have any clue.

hi

I was trying to train cascade using opencv_traincascade binary, I am using linux 3.7, Below is result of my command

PARAMETERS:
cascadeDirName: imgs/cascade/
vecFileName: imgs/vector.vec
bgFileName: negative.dat
numPos: 200
numNeg: 8
numStages: 10
precalcValBufSize[Mb] : 256
precalcIdxBufSize[Mb] : 256
stageType: BOOST
featureType: LBP
sampleWidth: 24
sampleHeight: 24
boostType: GAB
minHitRate: 0.995
maxFalseAlarmRate: 0.9
weightTrimRate: 0.95
maxDepth: 1
maxWeakCount: 100

===== TRAINING 0-stage =====
<BEGIN
OpenCV Error: Bad argument (Can not get new positive sample. The most possible reason is insufficient count of samples in given vec-file.
) in get, file /home/abuild/rpmbuild/BUILD/OpenCV-2.4.3/apps/traincascade/imagestorage.cpp, line 159
terminate called after throwing an instance of 'cv::Exception'
  what():  /home/abuild/rpmbuild/BUILD/OpenCV-2.4.3/apps/traincascade/imagestorage.cpp:159: error: (-5) Can not get new positive sample. The most possible reason is insufficient count of samples in given vec-file.
 in function get

./cascade_taining.sh: line 38: 11514 Aborted                 opencv_traincascade -data imgs/cascade/ -numPos 200 -numNeg 8 -numStages 10 -featureType LBP -maxFalseAlarmRate 0.9 -w 24 -h 24 -vec imgs/vector.vec -bg negative.dat

I wanted to verify my vector file and background file, I dont know how to do it.

Thanks Anshul