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GradientMagnitudeImage


Module: FoundationLite

Measures the strength of gradient at each pixel location.

Name Type Range Description
Input value
inImage Image Input image
Input value
inRoi Region* Range of output pixels to be computed
Input value
inOperator GradientMaskOperator Defines how the gradient is computed
Input value
inMeasure MagnitudeMeasure Defines how the gradient magnitude is computed
Input value
inScale Integer 1 - 16 Scales the resulting gradient magnitudes
Output value
outValueImage Image Gradient magnitudes of the image

Description

The operation computes the magnitude of the intensity change at each pixel of the inImage. Firstly the selected inOperator is used to obtain two-dimensional gradient vector at each pixel. Then the magnitudes of the vectors are estimated using the inMeasure method.

Specified by inMeasure method computes magnitude (A) from horizontal gradient component (x) and vertical gradient component (y) using one of following formulas:
\[A_{Horizontal}=|x|\] \[A_{Vertical}=|y|\] \[A_{Average}=\frac{|x|+|y|}{2}\] \[A_{Sum}=|x|+|y|\] \[A_{Maximum}=Max(|x|,|y|)\] \[A_{Hypot}=\sqrt{x^{2}+y^{2} }\]

The magnitudes are multiplied by inScale factor and saturated if they exceed the greatest value of their type.

Examples

GradientMagnitudeImage performed on the sample image with inOperator = Sobel, inMeasure = Hypot.

Hardware Acceleration

This operation is optimized for SSSE3 technology for pixels of type: UINT8.

This operation is optimized for AVX2 technology for pixels of type: UINT8.

This operation is optimized for NEON technology for pixels of type: UINT8.

This operation supports automatic parallelization for multicore and multiprocessor systems.

Errors

This filter can throw an exception to report error. Read how to deal with errors in Error Handling.

List of possible exceptions:

Error type Description
DomainError Region exceeds an input image in GradientMagnitudeImage.

Complexity Level

This filter is available on Advanced Complexity Level.

Filter Group

This filter is member of GradientMagnitudeImage filter group.

See Also

  • GradientImage – Computes a gradient image with smoothing operator of any size. The output pixels are signed.