Class descriptor_t

Class Documentation

class descriptor_t

Represents a feature descriptor as a float vector.

The descriptor values can be normalized and converted to packed formats for matching or model input.

Public Types

using vector = std::vector<descriptor_t>

Typedef for a vector of descriptors.

Public Functions

inline descriptor_t()

Default constructor.

inline descriptor_t(const std::vector<float> &data_)

Construct a new Pointdescriptor_t object.

Parameters:

data_ – Descriptor values copied into internal storage.

inline descriptor_t(const descriptor_t &other_)

Copy constructor.

Parameters:

other_ – Descriptor instance copied into this object.

inline descriptor_t(float *data_, const size_t size_)

Construct a new descriptor_t object from a pointer to data.

Parameters:

  • data_ – Pointer to the first float value of the descriptor buffer.

  • size_ – Number of float values read from data_. and its size.

inline bool is_empty() const

Check if this descriptor is empty (all elements are zero).

Returns:

true when no descriptor values are stored.

inline const std::vector<float> &get_data() const

Get the description object.

Returns:

with the descriptor data.

inline size_t get_size() const

Get the size of the descriptor (number of elements).

Returns:

Number of float elements in this descriptor.

inline void normalize_l2()

Normalize the descriptor using L2 norm.

inline void normalize_l1()

Normalize the descriptor using L1 norm.

inline void sqrt()

Apply square root to each element of the descriptor.

inline void print() const

Print the descriptor values to the console.

Public Static Functions

static inline std::vector<float> flatten_descriptors(const descriptor_t::vector &descriptors_)

Flattens descriptors into a contiguous float buffer.

Parameters:

descriptors_ – Descriptor list appended sequentially into one buffer.

Returns:

Flat vector containing all descriptor values in order.

static inline std::vector<std::vector<float>> to_float_vector(const descriptor_t::vector &descriptors_)

Convert a vector of descriptors to a std::vector<std::vector<float>>.

Parameters:

descriptors_ – Descriptor list converted into nested float vectors.

Returns:

list of descriptors

static inline bool is_empty(const descriptor_t &descriptor_)

Check if a descriptor is empty (all elements are zero).

Parameters:

descriptor_ – Descriptor instance tested for stored values.

Returns:

true if all elements are zero, false otherwise.

Private Members

std::vector<float> _data

descriptor_t data, using a set of floats