boofcv.alg.feature.detect.intensity

Class HessianBlobIntensity

java.lang.Object

boofcv.alg.feature.detect.intensity.HessianBlobIntensity

public class HessianBlobIntensity
extends Object

Detects "blob" intensity using the image's second derivative. The Hessian (second derivative) matrix is defined as [ I_xx , I_xy ; I_xy , I_yy], where the subscript indicates a partial derivative of the input image. The trace and determinant of this matrix is commonly used to detect interest point intensities. These tend to be at a peak for blobs and circular type objects. The trace is commonly referred to as the Laplacian.

• Determinant: D_xx*D_yy + D_xy²
• Trace: |D_xx + D_yy|

Author:

Peter Abeles

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	HessianBlobIntensity.Type Different types of Hessian blob detectors

Constructor Summary

Constructors

Constructor and Description
HessianBlobIntensity()

Method Summary

Methods

Modifier and Type	Method and Description
static void	determinant(ImageFloat32 featureIntensity, ImageFloat32 hessianXX, ImageFloat32 hessianYY, ImageFloat32 hessianXY) Feature intensity using the Hessian matrix's determinant.
static void	determinant(ImageFloat32 featureIntensity, ImageSInt16 hessianXX, ImageSInt16 hessianYY, ImageSInt16 hessianXY) Feature intensity using the Hessian matrix's determinant.
static void	trace(ImageFloat32 featureIntensity, ImageFloat32 hessianXX, ImageFloat32 hessianYY) Feature intensity using the trace of the Hessian matrix.
static void	trace(ImageFloat32 featureIntensity, ImageSInt16 hessianXX, ImageSInt16 hessianYY) Feature intensity using the trace of the Hessian matrix.

Methods inherited from class java.lang.Object

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

Constructor Detail

HessianBlobIntensity

public HessianBlobIntensity()

Method Detail

determinant

public static void determinant(ImageFloat32 featureIntensity,
               ImageFloat32 hessianXX,
               ImageFloat32 hessianYY,
               ImageFloat32 hessianXY)

Feature intensity using the Hessian matrix's determinant.

Parameters:

featureIntensity - Output feature intensity. Modified.

hessianXX - Second derivative along x-axis. Not modified.

hessianYY - Second derivative along y-axis. Not modified.

hessianXY - Second derivative along x-axis and y-axis. Not modified.

trace

public static void trace(ImageFloat32 featureIntensity,
         ImageFloat32 hessianXX,
         ImageFloat32 hessianYY)

Feature intensity using the trace of the Hessian matrix. This is also known as the Laplacian.

Parameters:

featureIntensity - Output feature intensity. Modified.

hessianXX - Second derivative along x-axis. Not modified.

hessianYY - Second derivative along y-axis. Not modified.

determinant

public static void determinant(ImageFloat32 featureIntensity,
               ImageSInt16 hessianXX,
               ImageSInt16 hessianYY,
               ImageSInt16 hessianXY)

Feature intensity using the Hessian matrix's determinant.

Parameters:

featureIntensity - Output feature intensity. Modified.

hessianXX - Second derivative along x-axis. Not modified.

hessianYY - Second derivative along y-axis. Not modified.

hessianXY - Second derivative along x-axis and y-axis. Not modified.

trace

public static void trace(ImageFloat32 featureIntensity,
         ImageSInt16 hessianXX,
         ImageSInt16 hessianYY)

Feature intensity using the trace of the Hessian matrix. This is also known as the Laplacian.

Parameters:

featureIntensity - Output feature intensity. Modified.

hessianXX - Second derivative along x-axis. Not modified.

hessianYY - Second derivative along y-axis. Not modified.