| Face Engine SDK 5.12.0 A face detection, recognition and tracking engine.

Public Member Functions | List of all members
fsdk::IDescriptorMatcher Struct Referenceabstract
Descriptor extractor

Descriptor matcher interface. More...

`#include <IDescriptor.h>`

Inheritance diagram for fsdk::IDescriptorMatcher:

## Public Member Functions
virtual ResultValue< FSDKError, MatchingResult > | match (const IDescriptor *first, const IDescriptor *second) noexcept=0
| Match descriptors 1:1. More...
virtual Result< FSDKError > | match (const IDescriptor *reference, const IDescriptorBatch *candidates, Span< MatchingResult > results) noexcept=0
| Match descriptors 1:M. More...
virtual uint32_t | getModelVersion () const noexcept=0
| Get algorithm model version this matcher works with. More...
virtual Result< FSDKError > | calcSimilarity (Span< MatchingResult > distances) const noexcept=0
| Calculates similarity based on distance. More...
virtual Result< FSDKError > | calcDistance (Span< MatchingResult > similarities) const noexcept=0
| Calculates distance from similarity. More...
Public Member Functions inherited from fsdk::IRefCounted
virtual int32_t | retain () noexcept=0
| Increase strong reference count. More...
virtual int32_t | retainLocked () noexcept=0
| Increase strong reference count thread safely. More...
virtual int32_t | release () noexcept=0
| Decrease strong reference count. More...
virtual int32_t | getRefCount () const noexcept=0
| Get actual strong reference count. More...
virtual int32_t | retainWeak () noexcept=0
| Increase weak reference count. More...
virtual int32_t | releaseWeak () noexcept=0
| Decrease weak reference count. More...
virtual int32_t | getWeakRefCount () const noexcept=0
| Get actual weak reference count. More...

## Detailed Description

Descriptor matcher interface.

Matches descriptors 1:1 and 1:M (

See also
  IDescriptor and IDescriptorBatch interfaces).

As a result of the matching process the calling site gets a MatchingResult (or several of them in case of 1:M matching). The MatchingResult structure contains distance and similarity metrics.

Distance is measured in abstract units and tends to 0 for similar descriptors and to infinity for different ones. Similarity is the opposite metric and shows probability of two descriptors belonging to the same person; therfore it is normalized to [0..1] range.

See also
  MatchingResult for details.

## Member Function Documentation

## ◆ calcDistance()

virtual Result<FSDKError> fsdk::IDescriptorMatcher::calcDistance | ( | Span< MatchingResult > | similarities | ) | const
| pure virtual noexcept

Calculates distance from similarity.

The method gets similarity from `similarities`[i].similarity and assigns the result to `similarities`[i].distance.

Parameters

  [in] | similarities | is a mutable span of matching results with calculated similarity.

Returns
  Result with error code.

See also
  Span, MatchingResult, Result and FSDKError for details.

Note
  all spans should be based on user owned continuous collections.

## ◆ calcSimilarity()

virtual Result<FSDKError> fsdk::IDescriptorMatcher::calcSimilarity | ( | Span< MatchingResult > | distances | ) | const
| pure virtual noexcept

Calculates similarity based on distance.

The method gets distance from `distances`[i].distances. and assigns the result to `distances`[i].similarity.

Parameters

  [in] | dinstances | is a mutable span of matching results with calculated distances.

Returns
  Result with error code.

See also
  Span, MatchingResult, Result and FSDKError for details.

Note
  all spans should be based on user owned continuous collections.

## ◆ getModelVersion()

virtual uint32_t fsdk::IDescriptorMatcher::getModelVersion | ( |  | ) | const
| pure virtual noexcept

Get algorithm model version this matcher works with.

Returns
  Version as integral number.

## ◆ match() [1/2]

virtual ResultValue< FSDKError, MatchingResult> fsdk::IDescriptorMatcher::match | ( | const IDescriptor * | first,
|  | const IDescriptor * | second
| ) |  |
| pure virtual noexcept

Match descriptors 1:1.

Parameters

  [in] | first | first descriptor.
  [in] | second | second descriptor.

Returns
  ResultValue with error code and matching result.

See also
  MatchingResult, IDescriptor, ResultValue and FSDKError for details.

## ◆ match() [2/2]

virtual Result<FSDKError> fsdk::IDescriptorMatcher::match | ( | const IDescriptor * | reference,
|  | const IDescriptorBatch * | candidates,
|  | Span< MatchingResult > | results
| ) |  |
| pure virtual noexcept

Match descriptors 1:M.

Matches a reference descriptor to a batch of candidate descriptors. The results are layed out in the same order as the candidate descriptors in the batch.

Parameters

  [in] | reference | the reference descriptor.
  [in] | candidates | the candidate descriptor batch to match with the reference.
  [out] | results | span of matching results.

Note
  Length of `results` must be at least the same as the length of the candidates batch.

See also
  IDescriptorBatch::getMaxCount().

Returns
  Result with error code.

See also
  Span, MatchingResult, IDescriptor, IDescriptorBatch, Result and FSDKError for details.

Note
  all spans should be based on user owned continuous collections.

The documentation for this struct was generated from the following file:

- include/fsdk/IDescriptor.h