Class BOWImgDescriptorExtractor

Brute-force descriptor matcher. For each descriptor in the first set, this matcher finds the closest descriptor in the second set by trying each one.

Inheritance
System.Object
DisposableObject
DisposableCvObject
BOWImgDescriptorExtractor
Implements
Inherited Members
Namespace: OpenCvSharp
Assembly: OpenCvSharp.dll
Syntax
public class BOWImgDescriptorExtractor : DisposableCvObject, ICvPtrHolder

Constructors

| Improve this Doc View Source

BOWImgDescriptorExtractor(DescriptorMatcher)

The constructor.

Declaration
public BOWImgDescriptorExtractor(DescriptorMatcher dmatcher)
Parameters
Type Name Description
DescriptorMatcher dmatcher

Descriptor matcher that is used to find the nearest word of the trained vocabulary for each keypoint descriptor of the image.
| Improve this Doc View Source

BOWImgDescriptorExtractor(Feature2D, DescriptorMatcher)

The constructor.

Declaration
public BOWImgDescriptorExtractor(Feature2D dextractor, DescriptorMatcher dmatcher)
Parameters
Type Name Description
Feature2D dextractor

Descriptor extractor that is used to compute descriptors for an input image and its keypoints.
DescriptorMatcher dmatcher

Descriptor matcher that is used to find the nearest word of the trained vocabulary for each keypoint descriptor of the image.

Methods

| Improve this Doc View Source

Compute(InputArray, ref KeyPoint[], OutputArray, out Int32[][], Mat)

Computes an image descriptor using the set visual vocabulary.

Declaration
public void Compute(InputArray image, ref KeyPoint[] keypoints, OutputArray imgDescriptor, out int[][] pointIdxsOfClusters, Mat descriptors = null)
Parameters
Type Name Description
InputArray image

Image, for which the descriptor is computed.
OpenCvSharp.KeyPoint[] keypoints

Keypoints detected in the input image.
OutputArray imgDescriptor

Computed output image descriptor.
System.Int32[][] pointIdxsOfClusters

pointIdxsOfClusters Indices of keypoints that belong to the cluster. This means that pointIdxsOfClusters[i] are keypoint indices that belong to the i -th cluster(word of vocabulary) returned if it is non-zero.
Mat descriptors

Descriptors of the image keypoints that are returned if they are non-zero.
| Improve this Doc View Source

Compute(InputArray, OutputArray, out Int32[][])

Computes an image descriptor using the set visual vocabulary.

Declaration
public void Compute(InputArray keypointDescriptors, OutputArray imgDescriptor, out int[][] pointIdxsOfClusters)
Parameters
Type Name Description
InputArray keypointDescriptors

Computed descriptors to match with vocabulary.
OutputArray imgDescriptor

Computed output image descriptor.
System.Int32[][] pointIdxsOfClusters

Indices of keypoints that belong to the cluster. This means that pointIdxsOfClusters[i] are keypoint indices that belong to the i -th cluster(word of vocabulary) returned if it is non-zero.
| Improve this Doc View Source

Compute2(Mat, ref KeyPoint[], Mat)

Computes an image descriptor using the set visual vocabulary.

Declaration
public void Compute2(Mat image, ref KeyPoint[] keypoints, Mat imgDescriptor)
Parameters
Type Name Description
Mat image

Image, for which the descriptor is computed.
OpenCvSharp.KeyPoint[] keypoints

Keypoints detected in the input image.
Mat imgDescriptor

Computed output image descriptor.
| Improve this Doc View Source

DescriptorSize()

Returns an image descriptor size if the vocabulary is set. Otherwise, it returns 0.

Declaration
public int DescriptorSize()
Returns
Type Description
System.Int32
| Improve this Doc View Source

DescriptorType()

Returns an image descriptor type.

Declaration
public int DescriptorType()
Returns
Type Description
System.Int32
| Improve this Doc View Source

DisposeUnmanaged()

Releases unmanaged resources

Declaration
protected override void DisposeUnmanaged()
Overrides
| Improve this Doc View Source

GetVocabulary()

Returns the set vocabulary.

Declaration
public Mat GetVocabulary()
Returns
Type Description
Mat
| Improve this Doc View Source

SetVocabulary(Mat)

Sets a visual vocabulary.

Declaration
public void SetVocabulary(Mat vocabulary)
Parameters
Type Name Description
Mat vocabulary

Vocabulary (can be trained using the inheritor of BOWTrainer ). Each row of the vocabulary is a visual word(cluster center).

Implements