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Creates a region containing image pixels with values within the specified range.



public static void ThresholdToRegion
	AvlNet.Image inImage,
	float? inMinValue,
	float? inMaxValue,
	float inHysteresis,
	AvlNet.Region outRegion


Name Type Range Default Description
inImageAvlNet.ImageInput image.
inMinValuefloat?128.0fMinimum value of a pixel that is considered foreground (Auto = -INF). Default value: 128.0f.
inMaxValuefloat?Maximum value of a pixel that is considered foreground (Auto = +INF). Default value: atl::NIL.
inHysteresisfloat<0.0f, INF>0.0fDefines how much the threshold criteria are lowered for pixels neighboring with other foreground pixels. Default value: 0.0f.
outRegionAvlNet.RegionOutput region.


The operation is a cousin of ThresholdImage yet computes a region instead of an image. The resulting region contains those pixels of the input image that meet one of the following conditions:

  • Pixel value is in range [inMinValue, inMaxValue].
  • Pixel value is in range [inMinValue-inHysteresis, inMinValue) or in range (inMaxValue, inMaxValue+inHysteresis] and in the processed image there is a path of consecutive pixels of value in range [inMinValue-inHysteresis, inMaxValue+inHysteresis] that connects the pixel being considered and any pixel with value in range [inMinValue, inMaxValue].

If any of the parameters inMinValue, inMaxValue 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.


ThresholdToRegion performed on the sample image with inMinValue = 80.0, inMaxValue = auto.

Hardware Acceleration

This operation is optimized for SSE2 technology for pixels of types: 1xUINT8, 3xUINT8, 1xInt16.

This operation supports automatic parallelization for multicore and multiprocessor systems.

Hardware acceleration settings may be manipulated with Settings class.


List of possible exceptions:

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

Function Overrides

See also