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ReadMultipleDataMatrixCodes_Deprecated

Header:	FIL.h
Namespace:	fil

Detects and recognizes several Data Matrix codes.

Syntax

void fil::ReadMultipleDataMatrixCodes_Deprecated
(
	const fil::Image& inImage,
	ftl::Optional<const fil::Rectangle2D&> inRoi,
	ftl::Optional<const fil::CoordinateSystem2D&> inRoiAlignment,
	const fil::DataMatrixCodeParams& inCodeParams,
	int inMaxCodeCount,
	int inContrastThreshold,
	bool inAllowMultipleScales,
	int inFlags,
	ftl::Array<fil::DataCode>& outDataMatrixCodes,
	ftl::Array<fil::Path>& outCandidates,
	ftl::Optional<fil::Rectangle2D&> outAlignedRoi = ftl::NIL
)

Parameters

Name	Type	Range	Default	Description
inImage	const Image&			Input image
inRoi	Optional<const Rectangle2D&>		NIL	Region of interest
inRoiAlignment	Optional<const CoordinateSystem2D&>		NIL	Coordinate system for the region of interest
inCodeParams	const DataMatrixCodeParams&			Specification of codes that can be found
inMaxCodeCount	int	0 -	2	Maximum number of codes to be found
inContrastThreshold	int	1 -	20	Minimal difference between dark and bright modules
inAllowMultipleScales	bool		False	Specifies whether codes of different module sizes are expected
inFlags	int	0 -		Undocumented advanced tweaks for difficult cases
outDataMatrixCodes	Array<DataCode>&
outCandidates	Array<Path>&			Diagnostic information about detection results
outAlignedRoi	Optional<Rectangle2D&>		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: outAlignedRoi.

Description

This filter detects and recognizes data matrix codes on an image.

Supported code types: ECC 200 and ECC 000-140.

Hints

Specify the range of possible codes on an image by setting the inCodeParams input. The more narrow is the specification, the faster the filter works.

Set inCodeParams.Polarity to specify whether dark-on-bright or bright-on-dark codes are to be read.
Specify the range of possible code sizes with inCodeParams.MinRowCount, inCodeParams.MaxRowCount, inCodeParams.MinColumnCount, inCodeParams.MinColumnCount.
Specify the range of possible module sizes (in pixels) with inCodeParams.MinModuleSize and inCodeParams.MaxModuleSize.
Set inCodeParams.ExpectedGapSize according to the following rules:
- Zero – no gaps at all (modules are fully filled).
- Small – gaps up to 25% of the module size.
- Medium – gaps up to 50% of the module size; it may require a bigger Quiet Zone.
- Large – gaps up to 75%; comes with no guarantee.
Modify inCodeParams.MaxRectangleRatio if you expect to work also with non-square codes. The value specifies maximal ratio between the length of the longer side to the length of the shorter side.

Specify the maximal number of codes on a single image by setting inMaxCodeCount.
If the codes may appear with different module sizes, also set inAllowMultipleScales to True.
Set inContrastThreshold to a value, which is lower than minimal difference of pixel values between a dark and a bright module (contrast), but greater than maximal difference of pixel values within one module (noise level).
If you are having problems with reading codes from low quality images, consider adding image morphology or smoothing.