message: Avoid HOGDescriptor with sigma = 0
  Solve
diff: @@ -100,7 +100,7 @@ size_t HOGDescriptor::getDescriptorSize() const
  double HOGDescriptor::getWinSigma() const
  {
  - return winSigma >= 0 ? winSigma : (blockSize.width + blockSize.height)/8.;
  + return winSigma > 0 ? winSigma : (blockSize.width + blockSize.height)/8.;
  }
  bool HOGDescriptor::checkDetectorSize() const
  