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GradientImage_Mask


Module: FoundationLite

Computes a gradient image with a Sobel or Prewitt operator.

Name Type Range Description
Input value inImage Image Input image
Input value inRoi Region* Range of outGradientImage pixels to be computed
Input value inOperator GradientMaskOperator Defines how the gradient is computed
Input value inScale Integer 1 - 16 Scales the resulting gradients
Output value outGradientImage Image Gradients of the image
Diagnostic input diagGradientDirections Image Gradient directions presented in a human readable format

Description

The operation computes the image gradient, which is directional change of the image intensity at each pixel. Each pixel of the resulting two-channel outGradientImage represents the gradient at the corresponding inImage pixel as a two-dimensional vector (each dimension on a separate, signed image channel). The length and direction of the vector represents the strength and direction of the intensity change.

Note that the format of the resulting image is not perfectly legible for a human eye. Firstly, the resulting image contains negative values. Secondly, directions of the gradients are represented indirectly.

  • To extract information about the sole strength of the intensity change one could use GradientMagnitudeImage filter.

Examples

GradientImage_Mask performed on the sample image with inOperator = Sobel. Image on the right is actually an absolute value of the resulting outGradientImage, so negative pixel values are also visible.

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 GradientImage_Mask.

Complexity Level

This filter is available on Advanced Complexity Level.

Filter Group

This filter is member of GradientImage filter group.

See Also

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