Plugin lcvfeatures2d

This module contains elements for feature detection and matching. It resembles open cv's features 2D module.

import lcvfeatures2d 1.0

Summary

TypeKeypointListViewView for a list of keypoints.
TypeFeatureDetectorSelectionDefault text color
TypeDescriptorExtractorSelectionContains a selection for a descriptor extractor.
TypeFeatureObjectListList of detected features for an object.
TypeSelectionAreaArea that can be selected through a rectangle
TypeKeyPointWrapper for a found keypoint.
TypeFeatureDetectorDetector of features within an image. This is an abstract type.
TypeFastFeatureDetectorFAST FeatureDetector
TypeBriskFeatureDetectorBrisk FeatureDetector
TypeOrbFeatureDetectorOrb FeatureDetector
TypeMSerFeatureDetectorMSer FeatureDetector
TypesimpleBlobDetectorImplements a simple algorithm for extracting blobs from an image.
TypeDescriptorExtractorAbstract base class for computing descriptors from an images keypoints.
TypeBriskDescriptorExtractorDecsriptor extractor for the Brisk algorithm.
TypeOrbDescriptorExtractorDecsriptor extractor for the Orb algorithm.
TypeDMatchVectorVector of matches.
TypeDescriptorMatcherAbstract base class for matching keypoint descriptors.
TypeBruteForceMatcherFinds the closest descriptor match.
TypeFlannBasedMatcherFinds the closest descriptor k matches.
TypeDrawMatchesDraws matches between two sets of keypoints that were detected and matched.
TypeDescriptorMatchFilterFilter for descriptor matches.
TypeKeypointsToSceneMapContains a keypoints to scene map.
TypeMatchesToLocalKeypointTriggered when output is changed
TypeKeypointHomographyPerforms a homography based on the keypoints to scene.

KeypointListView type

InheritsColumn
Propertycolor headerColor
Propertycolor headerTextColor
Propertycolor backgroundColor
Propertycolor itemBackgroundColor
Propertycolor selectedItemBackgroundColor
PropertyMathDraw keypointHighlighter
PropertyFeatureDetector detector
PropertyDescriptorExtractor extractor
Propertyvariant descriptorValues
Propertyalias currentIndex
SignalkeypointMouseEnter(int index, point pt)
SignalkeypointMouseExit(int index, point pt)
SignalkeypointMouseSelected(int index, point pt)

View for a list of keypoints.

color headerColor property

Color for the header of the list.

color headerTextColor property

Color for the text.

color backgroundColor property

Main background color.

color itemBackgroundColor property

Background color for each item.

color selectedItemBackgroundColor property

Background color of selected item.

MathDraw keypointHighlighter property

Draws keypoints on a highlighter.

FeatureDetector detector property

Detector used.

DescriptorExtractor extractor property

Extractor used.

variant descriptorValues property

Given descriptor values.

keypointMouseEnter(int index, point pt) signal

Triggered when the mouse entered a keypoint region.

keypointMouseExit(int index, point pt) signal

Triggered when the mouse exited a keypoint section.

keypointMouseSelected(int index, point pt) signal

Triggered when a keypoint region was selected.

alias currentIndex property

Current index of the selected keypoint.

FeatureDetectorSelection type

InheritsQtQuick.Rectangle
Propertystring stateId
PropertyMat detectorInput
Propertyalias selectedName
Propertyalias selectedDetector
Propertyalias selectedPanelModel
Propertyalias selectedIndex
Propertycolor backgroundColor
Propertycolor textColor
Propertyint dropBoxHeight
SignalconfigurationUpdate
SignalcomboClicked()

string stateId property

Assigned when staticLoad is active.

configurationUpdate signal

Signal for configuration update.

Mat detectorInput property

Input used for the detector.

alias selectedName property

Name of the detector.

alias selectedDetector property

Selected detector.

alias selectedPanelModel property

Selected panel model.

alias selectedIndex property

Selected index.

color backgroundColor property

Background color used throughout the selections.

color textColor property

Default text color

int dropBoxHeight property

Height of the dropBox when selecting diferent feature detector.

comboClicked() signal

Emited when selection happens.

DescriptorExtractorSelection type

InheritsQtQuick.Rectangle
Propertystring stateId
PropertyFeatureDetector detector
Propertyalias selectedName
Propertyalias selectedExtractor
Propertyalias selectedPanelModel
Propertyalias selectedIndex
Propertycolor backgroundColor
Propertycolor textColor
Propertyint dropBoxHeight
SignalconfigurationUpdate
SignalcomboClicked()

Contains a selection for a descriptor extractor.

string stateId property

Assigned when staticLoad is active.

configurationUpdate signal

Signal for configuration update.

FeatureDetector detector property

Detector used.

alias selectedName property

Name of the extractor.

alias selectedExtractor property

Selected extractor.

alias selectedPanelModel property

Selected panel model.

alias selectedIndex property

Selected index.

color backgroundColor property

Background color used throughout the selections.

color textColor property

Default text color.

int dropBoxHeight property

Height of the dropBox when selecting diferent feature detector.

comboClicked() signal

Emited when selection happens.

FeatureObjectList type

InheritsQtQuick.Rectangle
PropertyFeatureDetector featureDetector
PropertyDescriptorExtractor descriptorExtractor
Propertyalias objectList
Propertyalias selectedIndex
PropertyFeatureDetector trainFeatureDetector
PropertyDescriptorExtractor trainDescriptorExtractor
PropertyFeatureDetector queryFeatureDetector
Propertyvar imageSource
Propertyvar querySource
Propertyreal minMatchDistanceCoeff
Propertyreal matchNndrRation
PropertyKeyPointVector drawQueryKeypoints
Propertyint drawMatchIndex
Propertystring stateId
SignalobjectAdded(Mat descriptors, var points, var color)
SignalobjectListLoaded(MatList list, var keypoints, var corners, var colors)
SignalobjectListCreated()
SignalobjectListCreated()

List of detected features for an object.

FeatureDetector featureDetector property

FeatureDetector used.

DescriptorExtractor descriptorExtractor property

DescriptorExtractor used.

objectAdded(Mat descriptors, var points, var color) signal

Triggered when an object was added.

objectListLoaded(MatList list, var keypoints, var corners, var colors) signal

Triggered when the object list was loaded.

objectListCreated() signal

Triggered when the object list was created.

alias objectList property

Actual list.

alias selectedIndex property

Index of the selected item.

{qmlType:FeatureObjectMatch} {qmlInherits:QtQuick.Rectangle} {qmlBrief:Object matcher for a list.

FeatureDetector trainFeatureDetector property

FeatureDetector used for training.

DescriptorExtractor trainDescriptorExtractor property

DescriptorExtractor used for training.

FeatureDetector queryFeatureDetector property

FeatureDetector used for querying.

var imageSource property

Image source.

var querySource property

Query source.

real minMatchDistanceCoeff property

Property for the actual matcher.

real matchNndrRation property

Property for the actual matcher.

objectListCreated() signal

Emited when the list is created.

KeyPointVector drawQueryKeypoints property

Keypoints recieved from the trainFeatureDetector.

int drawMatchIndex property

Index where to draw the matches at.

{qmlProperty:Index of the training image matches}.

string stateId property

Static state id. See StaticItem for more details.

SelectionArea type

InheritsQtQuick.MouseArea
Propertycolor selectionColor
Propertyreal selectionOpacity
PropertyRectangle highlightItem
Signalselected(int x, int y, int width, int height)

Area that can be selected through a rectangle

color selectionColor property

Color of the selection.

real selectionOpacity property

Opacity of the selection.

selected(int x, int y, int width, int height) signal

Triggered when a selection happens.

Rectangle highlightItem property

Contains the rectangle of the highlighted item.

KeyPoint type

InheritsQtObject
PropertyPoint2f pt
Propertyfloat size
Propertyfloat angle
Propertyfloat response
Propertyint octave
Propertyint classId

Wrapper for a found keypoint.

Point2f pt property

Coordinates of the keypoint.

float size property

Diameter of the meaningful keypoint neighborhood.

float angle property

Angle the keypoint was detected at.

float response property

The response by which the most strong keypoints have been selected. Can be used for the further sorting or subsampling.

int octave property

Keypoint octave.

int classId property

Id of the detected class for the keypoint.

FeatureDetector type

InheritsItem
PropertyMat input
Propertyoutput
PropertyMat mask
Propertyparams
Propertykeypoints

Detector of features within an image. This is an abstract type.

Mat input property

Image to detect the keypoints in.

output property

Drawn features from the input to another image.

Mat mask property

Limited amount of detections for a specific area.

params property

Parameters for detection.

keypoints property

Given keypoints.

FastFeatureDetector type

InheritsFeatureDetector

FAST FeatureDetector

Initialization parameters:

  • int threshold

  • bool nonmaxSuppression

BriskFeatureDetector type

InheritsFeatureDetector

Brisk FeatureDetector

Feature detector for the Brisk algorithm.

Initialization parameters:

  • int thresh
  • int octave
  • float patternScale

OrbFeatureDetector type

InheritsFeatureDetector

Orb FeatureDetector

Feature detector for the Orb algorithm.

Initialization parameters:

  • int nfeatures
  • float scaleFactor
  • int nlevels
  • int edgeThreshold
  • int firstLevel
  • int WTA_K
  • int scoreType

MSerFeatureDetector type

InheritsFeatureDetector

MSer FeatureDetector

Feature detector for the MSer algorithm:

  • int delta
  • int minArea
  • int maxArea
  • float maxVariation
  • float minDiversity
  • int maxEvolution
  • real areaThreshold
  • real minMargin
  • int edgeBlurSize

simpleBlobDetector type

Inherits

Implements a simple algorithm for extracting blobs from an image.

Algorithm:

  1. Convert the source image to binary images by applying thresholding with several thresholds from minThreshold (inclusive) to maxThreshold (exclusive) with distance thresholdStep between neighboring thresholds.

  2. Extract connected components from every binary image by findContours and calculate their centers.

  3. Group centers from several binary images by their coordinates. Close centers form one group that corresponds to one blob, which is controlled by the minDistBetweenBlobs parameter.

  4. From the groups, estimate final centers of blobs and their radiuses and return as locations and sizes of keypoints.

This class performs several filtrations of returned blobs. You should set filterBy to true/false to turn the corresponding filtration on or off.

Params:

  • filterByInertia
  • filterByConvexity
  • filterByColor
  • filterByCircularity
  • filterByArea

DescriptorExtractor type

InheritsItem
Propertykeypoints
Propertydescriptors
Propertyparams
PropertyisBinary

Abstract base class for computing descriptors from an images keypoints.

keypoints property

Detected keypoints of an image.

descriptors property

Computed result.

params property

Parameters given according to the type of descriptor extractor.

isBinary property

Wether this DescriptorExtractor is of binary type.

BriskDescriptorExtractor type

InheritsDescriptorExtractor

Decsriptor extractor for the Brisk algorithm.

OrbDescriptorExtractor type

InheritsDescriptorExtractor

Decsriptor extractor for the Orb algorithm.

Params:

  • int patchSize

DMatchVector type

InheritsItem

Vector of matches.

DescriptorMatcher type

InheritsItem

Abstract base class for matching keypoint descriptors.

It has two groups of match methods: for matching descriptors of an image with another image or with an image set.

Params:

  • queryDescriptors Query set of descriptors.
  • knn Count of best matches found per each query descriptor or less if a query descriptor has less than k possible matches in total.

BruteForceMatcher type

InheritsDescriptorMatcher

Finds the closest descriptor match.

Params:

  • int normType
  • bool crossCheck

FlannBasedMatcher type

InheritsDescriptorMatcher

Finds the closest descriptor k matches.

Initialize params:

  • KDTree

    • int trees
  • HierarchicalClustering

  • Lsh

    • int tableNumber
    • int keySize
    • int multiProbeLevel

DrawMatches type

InheritsMatDisplay
PropertyKeyPointVector keypoints1
PropertyKeyPointVector keypoints2
PropertyDMatchVector matches1to2
Propertyint matchIndex

Draws matches between two sets of keypoints that were detected and matched.

You can specify the match index to focus on specific match when drawing.

KeyPointVector keypoints1 property

Keypoints from the first source.

KeyPointVector keypoints2 property

Keypoints from the second source

DMatchVector matches1to2 property

Matches from the first source to second one.

int matchIndex property

Draw matches at this specified index.

DescriptorMatchFilter type

InheritsItem
PropertyDMatchVector matches1to2
PropertyDMatchVector matches1to2Out
Propertyreal minDistanceCoeff
Propertyreal maxDistance
Propertyreal nndrRatio

Filter for descriptor matches.

DMatchVector matches1to2 property

Matches from the first source to second one.

DMatchVector matches1to2Out property

Output of matches1to2.

real minDistanceCoeff property

Minimum distance that the match has to the actual outcome.

real maxDistance property

Maximum distance allowed betwen set of two matches.

real nndrRatio property

The match betwen the first match and it's next consecutive match.

KeypointsToSceneMap type

InheritsQtObject
Propertyint size()

Contains a keypoints to scene map.

int size() property

Size of the vector of the KeypointsToScene object.

MatchesToLocalKeypoint type

InheritsQtObject
PropertyDMatchVector matches1to2
Propertylist trainKeypointVectors
PropertyKeyPointVector queryKeypointVector
PropertyKeyPointToSceneMap output
Signalmatches1to2Changed()
SignaltrainKeypointVectorsChanged()
SignalqueryKeypointVectorChanged()
SignaloutputChanged()

Maps matches to local keypoint.

DMatchVector matches1to2 property

Matches from the first source to second one.

list trainKeypointVectors property

List of trained keypoint vectors.

KeyPointVector queryKeypointVector property

Query keypoint vector.

KeyPointToSceneMap output property

The mapped object.

matches1to2Changed() signal

Triggered when matches1to2 changed.

trainKeypointVectorsChanged() signal

Trigered when trainKeypointVectors is changed

queryKeypointVectorChanged() signal

Trigered when queryKeypointVector is changed

outputChanged() signal

Triggered when output is changed

KeypointHomography type

InheritsMatDisplay
PropertyKeyPointToSceneMap keypointsToScene
PropertyMat queryImage
PropertyArray objectCorners
PropertyArray objectColors
SignalkeypointsToSceneChanged()
SignalqueryImageChanged()
SignalobjectCornersChanged()
SignalobjectColorsChanged()

Performs a homography based on the keypoints to scene.

KeyPointToSceneMap keypointsToScene property

Keypoints to scene object.

Mat queryImage property

Query image used.

Array objectCorners property

An array of 4 points describing the obejct corners

Array objectColors property

Array of object colors.

keypointsToSceneChanged() signal

Triggered when KeypointsToScene is changed.

queryImageChanged() signal

Triggered when QueryImage is changed.

objectCornersChanged() signal

Trigered when objectCorners is changed.

objectColorsChanged() signal

Trigered when objectColors is changed.