message: objdetect: add input check in HOG detector
diff: @@ -68,6 +68,7 @@ enum {DESCR_FORMAT_COL_BY_COL, DESCR_FORMAT_ROW_BY_ROW};
  static int numPartsWithin(int size, int part_size, int stride)
  {
  + CV_Assert(stride != 0);
  return (size - part_size + stride) / stride;
  }
  @@ -80,6 +81,7 @@ static Size numPartsWithin(cv::Size size, cv::Size part_size,
  static size_t getBlockHistogramSize(Size block_size, Size cell_size, int nbins)
  {
  + CV_Assert(!cell_size.empty());
  Size cells_per_block = Size(block_size.width / cell_size.width,
  block_size.height / cell_size.height);
  return (size_t)(nbins * cells_per_block.area());
  @@ -87,6 +89,9 @@ static size_t getBlockHistogramSize(Size block_size, Size cell_size, int nbins)
  size_t HOGDescriptor::getDescriptorSize() const
  {
  + CV_Assert(!cellSize.empty());
  + CV_Assert(!blockStride.empty());
  +
  CV_Assert(blockSize.width % cellSize.width == 0 &&
  blockSize.height % cellSize.height == 0);
  CV_Assert((winSize.width - blockSize.width) % blockStride.width == 0 &&
  @@ -144,20 +149,20 @@ bool HOGDescriptor::read(FileNode& obj)
  if( !obj.isMap() )
  return false;
  FileNodeIterator it = obj["winSize"].begin();
  - it >> winSize.width >> winSize.height;
  + it >> winSize.width >> winSize.height; CV_Assert(!winSize.empty());
  it = obj["blockSize"].begin();
  - it >> blockSize.width >> blockSize.height;
  + it >> blockSize.width >> blockSize.height; CV_Assert(!blockSize.empty());
  it = obj["blockStride"].begin();
  - it >> blockStride.width >> blockStride.height;
  + it >> blockStride.width >> blockStride.height; CV_Assert(!blockStride.empty());
  it = obj["cellSize"].begin();
  - it >> cellSize.width >> cellSize.height;
  - obj["nbins"] >> nbins;
  + it >> cellSize.width >> cellSize.height; CV_Assert(!cellSize.empty());
  + obj["nbins"] >> nbins; CV_Assert(nbins > 0);
  obj["derivAperture"] >> derivAperture;
  obj["winSigma"] >> winSigma;
  obj["histogramNormType"] >> histogramNormType;
  obj["L2HysThreshold"] >> L2HysThreshold;
  obj["gammaCorrection"] >> gammaCorrection;
  - obj["nlevels"] >> nlevels;
  + obj["nlevels"] >> nlevels; CV_Assert(nlevels > 0);
  if (obj["signedGradient"].empty())
  signedGradient = false;
  else
  