Package boofcv.alg.feature.detect.interest

Class GeneralFeatureDetector<I extends ImageGray<I>,D extends ImageGray<D>>

java.lang.Object

boofcv.alg.feature.detect.interest.GeneralFeatureDetector<I,D>

Type Parameters:

I - Input image type.

D - Image derivative type.

public class GeneralFeatureDetector<I extends ImageGray<I>,D extends ImageGray<D>>
extends Object

Detects features which are local maximums and/or local minimums in the feature intensity image. A list of pixels to exclude as candidates can be provided. Image derivatives need to be computed externally and provided as needed. The passed in GeneralFeatureIntensity is used to determine if local maximums or minimums should be detected.

If a maximum number of features is specified then the N most intense features are returned. By default all found features are returned. Set to a value ≤ 0 to detect all features.

Field Summary

Fields

Modifier and Type	Field	Description
protected @Nullable QueueCorner	exclude	Corners which should be excluded from detection
protected @Nullable NonMaxSuppression	extractorMax
protected @Nullable NonMaxSuppression	extractorMin	extracts corners from the intensity image
protected int	featureLimit	The maximum number of features that can be detected.
protected QueueCorner	found
protected GeneralFeatureIntensity<I,D>	intensity
protected QueueCorner	maximums
protected QueueCorner	minimums
protected FastArray<Point2D_I16>	selected
protected FeatureSelectLimitIntensity<Point2D_I16>	selectMax

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	GeneralFeatureDetector()
	GeneralFeatureDetector(GeneralFeatureIntensity<I,D> intensity, @Nullable NonMaxSuppression extractorMin, @Nullable NonMaxSuppression extractorMax, FeatureSelectLimitIntensity<Point2D_I16> selectMax)	Specifies which algorithms to use and configures the detector.

Method Summary

Modifier and Type	Method	Description
@Nullable Class<D>	getDerivType()
@Nullable Class<I>	getImageType()
GrayF32	getIntensity()
boolean	getRequiresGradient()	If the image gradient is required for calculations.
boolean	getRequiresHessian()	If the image Hessian is required for calculations.
int	getSearchRadius()
float	getThreshold()	Returns the current feature extraction threshold.
boolean	isDetectMaximums()	true if it will detector local maximums
boolean	isDetectMinimums()	true if it will detector local minimums
void	process(I image, D derivX, D derivY, D derivXX, D derivYY, D derivXY)	Computes point features from image gradients.
void	setSearchRadius(int radius)	Species the search radius for the feature
void	setThreshold(float threshold)	Changes feature extraction threshold.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

maximums

protected QueueCorner maximums

minimums

protected QueueCorner minimums

exclude

@Nullable
protected @Nullable QueueCorner exclude

Corners which should be excluded from detection

selectMax

protected FeatureSelectLimitIntensity<Point2D_I16> selectMax

selected

protected FastArray<Point2D_I16> selected

featureLimit

protected int featureLimit

The maximum number of features that can be detected. If both maximums and minimums can be detected the the limit per set will be half this. If not a positive value then there is no limit.

extractorMin

@Nullable
protected @Nullable NonMaxSuppression extractorMin

extracts corners from the intensity image

extractorMax

@Nullable
protected @Nullable NonMaxSuppression extractorMax

intensity

protected GeneralFeatureIntensity<I extends ImageGray<I>,D extends ImageGray<D>> intensity

found

protected QueueCorner found

Constructor Details

GeneralFeatureDetector

public GeneralFeatureDetector(GeneralFeatureIntensity<I,D> intensity,
 @Nullable
 @Nullable NonMaxSuppression extractorMin,
 @Nullable
 @Nullable NonMaxSuppression extractorMax,
 FeatureSelectLimitIntensity<Point2D_I16> selectMax)

Specifies which algorithms to use and configures the detector.

Parameters:

intensity - Computes how much like the feature the region around each pixel is.

extractorMin - Extracts the corners from intensity image

GeneralFeatureDetector

protected GeneralFeatureDetector()

Method Details

process

public void process(I image,
 @Nullable
 D derivX,
 @Nullable
 D derivY,
 @Nullable
 D derivXX,
 @Nullable
 D derivYY,
 @Nullable
 D derivXY)

Computes point features from image gradients.

Parameters:

image - Original image.

derivX - image derivative in along the x-axis. Only needed if getRequiresGradient() is true.

derivY - image derivative in along the y-axis. Only needed if getRequiresGradient() is true.

derivXX - Second derivative. Only needed if getRequiresHessian() is true.

derivXY - Second derivative. Only needed if getRequiresHessian() is true.

derivYY - Second derivative. Only needed if getRequiresHessian() is true.

getRequiresGradient

public boolean getRequiresGradient()

If the image gradient is required for calculations.

Returns:

true if the image gradient is required.

getRequiresHessian

public boolean getRequiresHessian()

If the image Hessian is required for calculations.

Returns:

true if the image Hessian is required.

getIntensity

public GrayF32 getIntensity()

setThreshold

public void setThreshold(float threshold)

Changes feature extraction threshold.

Parameters:

threshold - The new feature extraction threshold.

getThreshold

public float getThreshold()

Returns the current feature extraction threshold.

Returns:

feature extraction threshold.

isDetectMinimums

public boolean isDetectMinimums()

true if it will detector local minimums

isDetectMaximums

public boolean isDetectMaximums()

true if it will detector local maximums

setSearchRadius

public void setSearchRadius(int radius)

Species the search radius for the feature

Parameters:

radius - Radius in pixels

getSearchRadius

public int getSearchRadius()

getImageType

@Nullable
public @Nullable Class<I> getImageType()

getDerivType

@Nullable
public @Nullable Class<D> getDerivType()