Start » Filter Reference » Image » Image Local Transforms » GradientMagnitudeImage
Advanced| Module: | FoundationLite |
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Measures the strength of gradient at each pixel location.
| Name | Type | Range | Description | |
|---|---|---|---|---|
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inImage | Image | Input image | |
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inRoi | Region* | Range of output pixels to be computed | |
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inOperator | GradientMaskOperator | Defines how the gradient is computed | |
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inMeasure | MagnitudeMeasure | Defines how the gradient magnitude is computed | |
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inScale | Integer | 1 - 16 | Scales the resulting gradient magnitudes |
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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
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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_Mask – Computes a gradient image with a Sobel or Prewitt operator.
- GradientImage – Computes a gradient image with smoothing operator of any size. The output pixels are signed.