opencv createsamples has no error, but no samples found


I’m using this tutorial, and I’m on the stage of creating lots of samples from my positive images. I’m using Windows.

This is the command:

perl bin/ positives.txt negatives.txt samples 1500\  "C:\opencv_built\bin\Release\opencv_createsamples.exe -bgcolor 0 -bgthresh 0 -maxxangle 1.1\   -maxyangle 1.1 maxzangle 0.5 -maxidev 40 -w 80 -h 40"

And this is what I get as output, for each of the positive images:

C:\opencv_built\bin\Release\opencv_createsamples.exe -bgcolor 0 -bgthresh 0 -max
xangle 1.1\   -maxyangle 1.1 maxzangle 0.5 -maxidev 40 -w 80 -h 40 -img 60inclin
ation_315azimuth.jpg -bg tmp -vec samples0inclination_315azimuth.jpg.vec -num 62

Info file name: (NULL)
Img file name: 60inclination_315azimuth.jpg
Vec file name: samples0inclination_315azimuth.jpg.vec
BG  file name: tmp
Num: 62
BG color: 0
BG threshold: 0
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: 80
Height: 40
Create training samples from single image applying distortions...

The messages seemed successful so I went into the samples folder expecting to see 1500 samples, but there’s nothing there! I noticed the info file is <NULL>, does that have anything to do with this? There doesn’t seem to be any error, what went wrong?


I’ve changed the command to include absolute paths for everything, eg

perl bin/ C:\my_work\code\opencv-haar-classifier-training-master\positive_images\ C:\my_work\code\opencv-haar-classifier-training-master\positive_images\ samples 1500\  "C:\opencv_built\bin\Release\opencv_createsamples.exe -bgcolor 0 -bgthresh 0 -maxxangle 1.1\   -maxyangle 1.1 maxzangle 0.5 -maxidev 40 -w 80 -h 40"

But still no luck!


I had a similar problem I’ll try to explain what I did, I hope it will solve you problem.

First of all the NULL after -info is normal. As said in the official documentation of OpenCV for opencv_createcamples you need to either input an image (-img) or a collection of images (-info) I’ll let you read the documentation for further understanding, but for this example you don’t need it.

Secondly you don’t need to put absolute paths in this command; here is my command:

perl bin/  positives.txt negatives.txt samples 1500 "opencv_createsamples -bgcolor 0 -bgthresh 0 -maxxangle 1.1 -maxyangle 1.1 -maxzangle 0.5 -maxidev 40 -w 42 -h 40"

to do this be sure to be at the root of the gitHub directory you have download (the parent one of bin) be sure that your positives.txt and negatives. txt are in this directory. Also copy paste the opencv_createsamples.exe from OpenCV directory in this one.

This done I’ll now explain the main problems: The project was developped for Ubuntu at the beginning so it works for mac easily but I think you must be under Windows. If you hadn’t already please download Cygwin because it uses mainly Linux commands.

As I said I was blocked with a similar problem, so I tried to use opencv_createsample directly instead of the perl script to see if the problem was coming from there and I noticed that the problem was coming from the fact that my positives.txt and negatives.txt were under Windows format and not Unix so the Perl script wasn’t able to read them properly.

The difference between windows and linux are big and Cygwin doesn’t bridge the gap so there might be other encoding problems. So what I did is surely not the fastest way to resolve the problem, but it is an easy one.

I just installed an Ubuntu vm on my PC

Installed Opencv with TBB ( a lot of tutorials internet, the best is the one from the OpenCV site).

I Downloaded the gitHub Classifier training and then I followed the commands given and it worked well.

Answered By – Lucas

Answer Checked By – Mildred Charles (AngularFixing Admin)

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