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CheckPresence_Intensity

Header:	FIL.h
Namespace:	fil
Module:	FoundationPro

Verifies object presence by analysing pixel intensities in the specified region.

Applications: Quick and easy presence verification, e.g. for missing caps, screws, labels.

Syntax

void fil::CheckPresence_Intensity
(
	const fil::Image& inImage,
	const fil::ShapeRegion& inRoi,
	ftl::Optional<const fil::CoordinateSystem2D&> inRoiAlignment,
	ftl::Optional<float> inMinIntensity,
	ftl::Optional<float> inMaxIntensity,
	float inMinContrast,
	ftl::Optional<float> inMaxContrast,
	bool& outIsPresent,
	ftl::Optional<float&> outIntensity = ftl::NIL,
	ftl::Optional<float&> outContrast = ftl::NIL,
	ftl::Optional<fil::ShapeRegion&> outAlignedRoi = ftl::NIL
)

Parameters

Name	Type	Range	Default	Description
inImage	const Image&			Input image
inRoi	const ShapeRegion&			Location at which object presence is being checked
inRoiAlignment	Optional<const CoordinateSystem2D&>		NIL	Adjusts the region of interest to the position of the inspected object
inMinIntensity	Optional<float>		NIL	Lowest acceptable value for the average pixel value
inMaxIntensity	Optional<float>		NIL	Highest acceptable value for the average pixel value
inMinContrast	float	0.0 -		Lowest acceptable value for the standard deviation of the pixel values
inMaxContrast	Optional<float>	0.0 -	NIL	Highest acceptable value for the standard deviation of the pixel values
outIsPresent	bool&			Flag indicating whether the object is present or not
outIntensity	Optional<float&>		NIL	Average pixel value
outContrast	Optional<float&>		NIL	Standard deviation of the pixel values
outAlignedRoi	Optional<ShapeRegion&>		NIL	Input ROI after transformation (in the image coordinates)

Optional Outputs

The computation of following outputs can be switched off by passing value ftl::NIL to these parameters: outIntensity, outContrast, outAlignedRoi.

Description

The filter computes basic statistics of the image pixels in selected ROI and checks if they fit the defined ranges. The used statistics are average and standard deviation of the pixel values.

Hints

If the object location is variable, Pass an appropriate local coordinate system to inRoiAlignment.
Define inRoi to specify the image location at which the object presence will be checked.
Investigate the values that appear on outIntensity and outContrast outputs. With this information set inMinIntensity, inMaxIntensity, inMinContrast and inMaxContrast to values which are appropriate for correct objects.
When creating data previews, use outAlignedRoi and NOT inRoi as only the former will be properly aligned to the object location.

Examples

CheckPresence_Intensity performed on sample image with inMinIntensity = 80. The foam is present in red rectangle.

Errors

List of possible exceptions:

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