OpenCV on debian armhf

1
votes

I have the code working on gentoo x64 with opencv-2.4.5:

VideoCapture cap;
cap.set(CV_CAP_PROP_FPS , 25);
cap.open(0);
Mat frame, edged;
cap >> frame;
Canny(frame, edged, 50, 200, 5);

but it doesnt work on debian armhf with opencv 2.3.

OpenCV Error: Unsupported format or combination of formats () in cvCanny, file /build/buildd-opencv_2.3.1-11-armhf-d9JIli/opencv-2.3.1/modules/imgproc/src/canny.cpp, line 67 terminate called after throwing an instance of 'cv::Exception' what(): /build/buildd-opencv_2.3.1-11-armhf-d9JIli/opencv-2.3.1/modules/imgproc/src/canny.cpp:67: error: (-210) in function cvCanny

What's wrong?

1
c++opencv

1 Answers

0
votes

not really an answer, but ...

  • 2.3.1 is damn old . no facereco, no stitching, baaa
  • afaik, you can't set params on VideoCapture before opening it

  • you want to check, if cap.open(0) actually succeeded, either the return value, or

    if ( ! cap.isOpened() ) // rrrr ;(

  • some webcams need a 'warmup' time, and deliver empty/invalid frames on startup, so check

    if ( frame.empty() ) continue; // play it again, sam

(your error message hints at an empty frame)