boofcv.alg.feature.detect.intensity

Class HessianBlobIntensity

java.lang.Object

boofcv.alg.feature.detect.intensity.HessianBlobIntensity

public class HessianBlobIntensity
extends java.lang.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|

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

Modifier and Type	Method and Description
static void	determinant(GrayF32 featureIntensity, GrayF32 hessianXX, GrayF32 hessianYY, GrayF32 hessianXY) Feature intensity using the Hessian matrix's determinant.
static void	determinant(GrayF32 featureIntensity, GrayS16 hessianXX, GrayS16 hessianYY, GrayS16 hessianXY) Feature intensity using the Hessian matrix's determinant.
static void	trace(GrayF32 featureIntensity, GrayF32 hessianXX, GrayF32 hessianYY) Feature intensity using the trace of the Hessian matrix.
static void	trace(GrayF32 featureIntensity, GrayS16 hessianXX, GrayS16 hessianYY) Feature intensity using the trace of the Hessian matrix.

Methods inherited from class java.lang.Object

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

Constructor Detail

HessianBlobIntensity

public HessianBlobIntensity()

Method Detail

determinant

public static void determinant(GrayF32 featureIntensity,
                               GrayF32 hessianXX,
                               GrayF32 hessianYY,
                               GrayF32 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(GrayF32 featureIntensity,
                         GrayF32 hessianXX,
                         GrayF32 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(GrayF32 featureIntensity,
                               GrayS16 hessianXX,
                               GrayS16 hessianYY,
                               GrayS16 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(GrayF32 featureIntensity,
                         GrayS16 hessianXX,
                         GrayS16 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.