其定义在 object.hpp中找到的：

struct CV_EXPORTS_W HOGDescriptor
{
public:
enum { L2Hys=0 };
enum { DEFAULT_NLEVELS=64 };

CV_WRAP HOGDescriptor() : winSize(64,128), blockSize(16,16), blockStride(8,8),
cellSize(8,8), nbins(9), derivAperture(1), winSigma(-1),
histogramNormType(HOGDescriptor::L2Hys), L2HysThreshold(0.2), gammaCorrection(true),
nlevels(HOGDescriptor::DEFAULT_NLEVELS)
{}

CV_WRAP HOGDescriptor(Size _winSize, Size _blockSize, Size _blockStride,
Size _cellSize, int _nbins, int _derivAperture=1, double _winSigma=-1,
int _histogramNormType=HOGDescriptor::L2Hys,
double _L2HysThreshold=0.2, bool _gammaCorrection=false,
int _nlevels=HOGDescriptor::DEFAULT_NLEVELS)
: winSize(_winSize), blockSize(_blockSize), blockStride(_blockStride), cellSize(_cellSize),
nbins(_nbins), derivAperture(_derivAperture), winSigma(_winSigma),
histogramNormType(_histogramNormType), L2HysThreshold(_L2HysThreshold),
gammaCorrection(_gammaCorrection), nlevels(_nlevels)
{}

CV_WRAP HOGDescriptor(const String& filename)
{
load(filename);
}

HOGDescriptor(const HOGDescriptor& d)
{
d.copyTo(*this);
}

virtual ~HOGDescriptor() {}

CV_WRAP size_t getDescriptorSize() const;
CV_WRAP bool checkDetectorSize() const;
CV_WRAP double getWinSigma() const;

CV_WRAP virtual void setSVMDetector(InputArray _svmdetector);

virtual bool read(FileNode& fn);
virtual void write(FileStorage& fs, const String& objname) const;

CV_WRAP virtual bool load(const String& filename, const String& objname=String());
CV_WRAP virtual void save(const String& filename, const String& objname=String()) const;
virtual void copyTo(HOGDescriptor& c) const;

CV_WRAP virtual void compute(const Mat& img,
CV_OUT vector& descriptors,
Size winStride=Size(), Size padding=Size(),
const vector& locations=vector()) const;
//with found weights output
CV_WRAP virtual void detect(const Mat& img, CV_OUT vector& foundLocations,
CV_OUT vector& weights,
double hitThreshold=0, Size winStride=Size(),
Size padding=Size(),
const vector& searchLocations=vector()) const;
//without found weights output
virtual void detect(const Mat& img, CV_OUT vector& foundLocations,
double hitThreshold=0, Size winStride=Size(),
Size padding=Size(),
const vector& searchLocations=vector()) const;
//with result weights output
CV_WRAP virtual void detectMultiScale(const Mat& img, CV_OUT vector& foundLocations,
CV_OUT vector& foundWeights, double hitThreshold=0,
Size winStride=Size(), Size padding=Size(), double scale=1.05,
double finalThreshold=2.0,bool useMeanshiftGrouping = false) const;
//without found weights output
virtual void detectMultiScale(const Mat& img, CV_OUT vector& foundLocations,
double hitThreshold=0, Size winStride=Size(),
Size padding=Size(), double scale=1.05,
double finalThreshold=2.0, bool useMeanshiftGrouping = false) const;