Package boofcv.alg.filter.derivative

Class HessianSobel

java.lang.Object

boofcv.alg.filter.derivative.HessianSobel

public class HessianSobel
extends Object

Computes the second derivative (Hessian) of an image using. This hessian is derived using the GradientSobel gradient function.

WARNING: It is computationally more expensive to compute the Hessian with this operation than applying the Sobel gradient operator multiple times. However, this does not require the creation additional storage to save intermediate results.

Kernel for ∂ ²f/∂ y²:

</table} [1 0 -2 0 1] and ∂²f/∂ x∂y is:

1	4	6	4	1
0	0	0	0	0
-2	-8	-12	-8	-2
0	0	0	0	0
1	4	6	4	1

</table}

Field Summary

Fields

Modifier and Type	Field	Description
static Kernel2D_F32	kernelXX_F32
static Kernel2D_S32	kernelXX_I32
static Kernel2D_F32	kernelXY_F32
static Kernel2D_S32	kernelXY_I32
static Kernel2D_F32	kernelYY_F32
static Kernel2D_S32	kernelYY_I32

Constructor Summary

Constructors

Constructor	Description
HessianSobel()

Method Summary

Modifier and Type	Method	Description
static void	process(GrayF32 orig, GrayF32 derivXX, GrayF32 derivYY, GrayF32 derivXY, @Nullable ImageBorder_F32 border)	Computes the image's second derivatives.
static void	process(GrayU8 orig, GrayS16 derivXX, GrayS16 derivYY, GrayS16 derivXY, @Nullable ImageBorder_S32 border)	Computes the image's second derivatives.
static <I extends ImageGray<I>, D extends ImageGray<D>> void	process(I input, D derivXX, D derivYY, D derivXY, @Nullable ImageBorder border)

Methods inherited from class java.lang.Object

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

Field Details

kernelYY_I32

public static Kernel2D_S32 kernelYY_I32

kernelXX_I32

public static Kernel2D_S32 kernelXX_I32

kernelXY_I32

public static Kernel2D_S32 kernelXY_I32

kernelYY_F32

public static Kernel2D_F32 kernelYY_F32

kernelXX_F32

public static Kernel2D_F32 kernelXX_F32

kernelXY_F32

public static Kernel2D_F32 kernelXY_F32

Constructor Details

HessianSobel

public HessianSobel()

Method Details

process

public static <I extends ImageGray<I>,
D extends ImageGray<D>>
void process(I input,
 D derivXX,
 D derivYY,
 D derivXY,
 @Nullable
 @Nullable ImageBorder border)

process

public static void process(GrayU8 orig,
 GrayS16 derivXX,
 GrayS16 derivYY,
 GrayS16 derivXY,
 @Nullable
 @Nullable ImageBorder_S32 border)

Computes the image's second derivatives.

Parameters:

orig - Which which is to be differentiated. Not Modified.

derivXX - Second derivative along the x-axis. Modified.

derivYY - Second derivative along the y-axis. Modified.

derivXY - Second cross derivative. Modified.

border - Specifies how the image border is handled. If null the border is not processed.

process

public static void process(GrayF32 orig,
 GrayF32 derivXX,
 GrayF32 derivYY,
 GrayF32 derivXY,
 @Nullable
 @Nullable ImageBorder_F32 border)

Computes the image's second derivatives.

Parameters:

orig - Which which is to be differentiated. Not Modified.

derivXX - Second derivative along the x-axis. Modified.

derivYY - Second derivative along the y-axis. Modified.

derivXY - Second cross derivative. Modified.

border - Specifies how the image border is handled. If null the border is not processed.

1	2	0	-2	-1
2	4	0	-4	-2
0	0	0	0	0
-2	-4	0	4	2
-1	-2	0	2	1