The matrix is not continuous... got an error when executing face recognition from video

asked 2013-07-25 04:20:30 -0500

Babbling gravatar image

Hi, I am new to OpenCV and I am following the tutorial ( to make a face recognition from the webcamera.

After I used the following command, I got the error

"./Facerec_Video '/root/Documents/Facial_Recgonition/opencv/libfacerec/samples/New/haarcascade_frontalface_default.xml' '/root/Documents/Facial_Recgonition/opencv/libfacerec/samples/New/data.csv' /dev/video0"

Facerec_Video is the executable file and the following three arguments are Haarcascade file, CSV file, and my webcamera.

OpenCV Error: Image step is wrong (The matrix is not continuous, thus its number of rows can not be changed) in reshape, file /build/opencv/src/opencv-, line 802 terminate called after throwing an instance of 'cv::Exception' what(): /build/opencv/src/opencv- error: (-13) The matrix is not continuous, thus its number of rows can not be changed in function reshape Aborted (core dumped)

I used the AT&T database and the CSV file and source code copied from the tutorial. Can anyone give me some clues? Thank you.

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could you debug it a bit / throw in some print statements, to find out , where it happens ? (my guess would be the predict() method)

did you modify the code in one way or another ?

berak gravatar imageberak ( 2013-07-25 08:55:24 -0500 )edit

In JavaCv 4.5, there is a bug in the CvMat.isContinuous function that applies a mask to the results of calling type() which itself applies a mask to raw_type losing the bit that indicates the matrix is continuous.

i.e. public boolean isContinuous() { return opencv_core.CV_IS_MAT_CONT(type()); }

Perhaps the same problem exists in the C++ source

Dave Employed gravatar imageDave Employed ( 2013-12-03 16:46:19 -0500 )edit

Same problem and I have tried some solutions in the forum. The error is in model.train() line of the tutorial. I have tried with parameters in createFisherRecognizer, also converting images to pgm and nothin changes.

marilia15 gravatar imagemarilia15 ( 2015-10-14 14:25:04 -0500 )edit

please check, if you got some non-image file in there. (if so, just remove it)

again - imread() will just return silently with an empty (non-valid, not-continous Mat) in this case.

berak gravatar imageberak ( 2015-10-14 14:32:54 -0500 )edit