CalculateGradient

MLModule

genre	Filters
author	MeVis Medical Solutions AG
package	MeVisLab/Standard
dll	MLFilter1
definition	mlFilter1.def
see also	MorphologicalGradient
keywords	calculation, derivative, vector, field, edge, detection

Purpose

The module CalculateGradient performs edge detection and edge enhancement by calculating the local gradient in ML images.

Windows

Default Panel

Input Fields

input0

name: input0, type: Image

The image for gradient calculation.

inputXMarkerList

name: inputXMarkerList, type: XMarkerList(MLBase)

The first marker of the input marker list can be used as a center position for radial gradient computation.

For accessing this object via scripting see the Scripting Reference: MLXMarkerListWrapper.

Output Fields

output0

name: output0, type: Image

Computed gradient image.

Parameter Fields

Field Index

C (c_Derivative): Bool	status: String	Y: Bool
C (c_VoxelSize): Float	Step Width: Integer	Z: Bool
Direction: Enum	T (t_Derivative): Bool
Edge Mode: Enum	T (t_VoxelSize): Float
Factor: Float	U (u_Derivative): Bool
Mode (gradientMode): Enum	U (u_VoxelSize): Float
Mode (enhanceMode): Enum	Width: Float
Radius: Float	X: Bool

Visible Fields

X

name: x_Derivative, type: Bool, default: TRUE, deprecated name: X\_Derivative

If checked, the gradient in x-direction is computed.

Y

name: y_Derivative, type: Bool, default: TRUE, deprecated name: Y\_Derivative

If checked, the gradient in y-direction is computed.

Z

name: z_Derivative, type: Bool, default: FALSE, deprecated name: Z\_Derivative

If checked, the gradient in z-direction is computed.

C (c_Derivative)

name: c_Derivative, type: Bool, default: FALSE, deprecated name: C\_Derivative

If checked, the gradient in c-direction is computed.

T (t_Derivative)

name: t_Derivative, type: Bool, default: FALSE, deprecated name: T\_Derivative

If checked, the gradient in t-direction is computed.

U (u_Derivative)

name: u_Derivative, type: Bool, default: FALSE, deprecated name: U\_Derivative

If checked, the gradient in u-direction is computed.

C (c_VoxelSize)

name: c_VoxelSize, type: Float, default: 1, deprecated name: C\_VoxelSize

Sets the voxel size for gradient computation in c-direction.

T (t_VoxelSize)

name: t_VoxelSize, type: Float, default: 1, deprecated name: T\_VoxelSize

Sets the voxel size for gradient computation in t-direction.

U (u_VoxelSize)

name: u_VoxelSize, type: Float, default: 1, deprecated name: U\_VoxelSize

Sets the voxel size for gradient computation in u-direction.

Mode (gradientMode)

name: gradientMode, type: Enum, default: Max, deprecated name: GradientMode

Defines the gradient computation mode.

Values:

Title	Name	Description
Max	Max	Writes the maximum gradient value to the output image.
Norm	Norm	Writes the normalized gradient value into the output image.
Radial	Radial	Writes a radial gradient value into the output image. The radial gradient is computed from the image center or from the position of the first marker if a marker list is attached.
2nd Deriv Max	2ndDeriv_Max	Writes the maximum value of the second derivative gradient into the output image.
2nd Deriv Norm	2ndDeriv_Norm	Writes the normalized value of the second derivative gradient into the output image.
2nd Deriv Radial	2ndDeriv_Radial	Writes a second derivative radial gradient value into the output image. The radial gradient is computed from the image center or from the position of the first marker if a marker list is attached.
Curvature	Curvature	Writes a curvature value into the output image.
Separate	Separate	Writes the separate gradient values for x, y and z into the u-dimension of the output image.
Abs Separate	AbsSeparate	Writes the absolute separate gradient values for x, y and z into the u-dimension of the output image.

Direction

name: gradientType, type: Enum, default: Central

Defines the type of gradient computation.

Values:

Title	Name
Central	Central
Inferior	Inferior
Superior	Superior

Edge Mode

name: edgeMode, type: Enum, default: Const, deprecated name: EdgeMode

Defines the edge mode for gradient computation.

Values:

Title	Name
Const	Const
Linear	Linear

Step Width

name: stepWidth, type: Integer, default: 1, minimum: 1, maximum: 10, deprecated name: StepWidth

Sets the step width or kernel size in x, y and z direction for gradient computation. Larger step width leads to smaller gradient values.

Mode (enhanceMode)

name: enhanceMode, type: Enum, default: None, deprecated name: EnhanceMode

Defines the enhancement mode for gradient computation.

Values:

Title	Name
None	None
Triangular	Triangular
Gauss	Gauss

Radius

name: estRadius, type: Float, default: 0, minimum: 0, maximum: 100, deprecated name: EstRadius

Sets a radius for the Mode.

Factor

name: enhanceFactor, type: Float, default: 0, minimum: 0, maximum: 10, deprecated name: EnhanceFactor

Sets a factor for the Mode.

Width

name: enhanceWidth, type: Float, default: 0, minimum: 0, maximum: 100, deprecated name: EnhanceWidth

Sets a width for the Mode.

Hidden Fields

status

name: status, type: String, deprecated name: Status