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ThresholdToRegion_Relative

Header:	FIL.h
Namespace:	fil
Module:	FoundationBasic

Thresholds an image with a different threshold value for each pixel (inBaseImage(x, y) + inValue).

Syntax

void fil::ThresholdToRegion_Relative
(
	const fil::Image& inImage,
	ftl::Optional<const fil::Region&> inRoi,
	const fil::Image& inBaseImage,
	ftl::Optional<float> inMinRelativeValue,
	ftl::Optional<float> inMaxRelativeValue,
	float inHysteresis,
	fil::Region& outRegion
)

Parameters

Name	Type	Range	Default	Description
inImage	const Image&			Input image
inRoi	Optional<const Region&>		NIL	Region of interest
inBaseImage	const Image&			Pixels of this image are subtracted from inImage before thresholding
inMinRelativeValue	Optional<float>		128.0f	Minimum relative value of a pixel that is considered foreground (Auto = -INF)
inMaxRelativeValue	Optional<float>		NIL	Maximum relative value of a pixel that is considered foreground (Auto = +INF)
inHysteresis	float	0.0 -	0.0f	Defines how much the threshold criteria are lowered for pixels neighboring with other foreground pixels
outRegion	Region&			Output region

Description

The operation is a cousin of ThresholdImage_Relative yet computes a region instead of an image. The resulting region contains only those pixels of the input image, which are brighter at least by inMinRelativeValue and at most by inMaxRelativeValue than the corresponding pixel of inBaseImage. If any of the parameters inMinRelativeValue, inMaxRelativeValue is not set, it is assumed to be, accordingly, -infinity or infinity.

In the multichannel images the operation uses an average of channel values in each pixel.

Examples

A sample image used as inImage.

A sample image used as inBaseImage.

ThresholdToRegion_Relative performed with inMinRelativeValue = 0.0, inMaxRelativeValue = auto.

Hardware Acceleration

This operation is optimized for SSE2 technology for pixels of types: 1xUINT8, 3xUINT8.

This operation is optimized for NEON technology for pixels of types: 1xUINT8, 3xUINT8.

This operation supports automatic parallelization for multicore and multiprocessor systems.

Errors

List of possible exceptions:

Error type	Description
DomainError	Image formats are not the same in ThresholdToRegion_Relative.
DomainError	Image sizes are not equal in ThresholdToRegion_Relative.
DomainError	Region exceeds an input image in ThresholdToRegion_Relative.