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AVL.ThresholdImage_Hysteresis(AvlNet.Image, AvlNet.Region, float?, float?, float, AvlNet.Image)

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

Namespace:AvlNet
Assembly:AVL.NET.dll

Syntax


public static void ThresholdImage_Hysteresis(
	AvlNet.Image inImage,
	AvlNet.Region inRoi,
	float? inMinValue,
	float? inMaxValue,
	float inHysteresis,
	out AvlNet.Image outMonoImage
)

Parameters

inImage
Type: AvlNet.Image
Input image
inRoi
Type: AvlNet.Region
Region of interest, or null.
inMinValue
Type: System.Nullable<System.Single>
Minimum value of a pixel that is considered foreground (Auto = -INF), or null.
inMaxValue
Type: System.Nullable<System.Single>
Maximum value of a pixel that is considered foreground (Auto = +INF), or null.
inHysteresis
Type: System.Single
Defines how much the threshold criteria are lowered for pixels neighboring with other foreground pixels
outMonoImage
Type: AvlNet.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.

See also