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FIL.ThresholdImage_Hysteresis

Thresholds an image with a hysteresis, i.e. with a lower threshold for neighboring pixels.

Namespace:FilNet
Assembly:FIL.NET.dll

Syntax

C++
C#
 
public static void ThresholdImage_Hysteresis
(
	FilNet.Image inImage,
	NullableRef<FilNet.Region> inRoi,
	float? inMinValue,
	float? inMaxValue,
	float inHysteresis,
	FilNet.Image outMonoImage
)

Parameters

Name Type Range Default Description
inImageFilNet.ImageInput image.
inRoiFilNet.NullableRef<FilNet.Region>Region of interest. Default value: ftl::NIL.
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: ftl::NIL.
inHysteresisfloat<0.0f, INF>16.0fDefines how much the threshold criteria are lowered for pixels neighboring with other foreground pixels. Default value: 16.0f.
outMonoImageFilNet.Image

Description

The operation transforms each pixel value to the maximum or minimum level thus creating binary image. The result of the transformation depends on the pixel intensity:

  • Pixel values in range [inMinValue, inMaxValue] are transformed to the maximum level.
  • Pixel values lower than inMinValue-inHysteresis or higher than inMaxValue+inHysteresis are transformed to the minimum level.
  • Pixel values in range [inMinValue-inHysteresis, inMinValue) or in range (inMaxValue, inMaxValue+inHysteresis] are transformed to the maximum if (and only if) 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].

In the multichannel images the operation uses an average of channel values in each pixel, thus the resulting image is always monochromatic.

Examples

ThresholdImage_Hysteresis performed on the sample image with inMinValue = 110.0, inMaxValue = Nil, inHysteresis = 15.0.

Pixels of the sample image brighter than 110.0.

Pixels of the sample image brighter than 95.0.

Hardware Acceleration

This operation supports automatic parallelization for multicore and multiprocessor systems.

Hardware acceleration settings may be manipulated with Settings class.

Errors

List of possible exceptions:

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

Function Overrides

See also