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ReadSingleBarcode

Header:	AVL.h
Namespace:	avl
Module:	Barcodes

Detects and recognizes a single barcode on the input image.

Applications: To be used as an easy all-in-one solution for typical barcode reading applications.

Syntax

void avl::ReadSingleBarcode
(
	const avl::Image& inImage,
	atl::Optional<const avl::ShapeRegion&> inRoi,
	atl::Optional<const avl::CoordinateSystem2D&> inRoiAlignment,
	const avl::BarcodeParams& inBarcodeParams,
	const avl::BarcodeDetectionParams& inDetectionParams,
	atl::Conditional<avl::Barcode>& outBarcode,
	atl::Optional<atl::Array<avl::Rectangle2D>&> outBarcodeCandidates = atl::NIL,
	atl::Optional<avl::ShapeRegion&> outAlignedRoi = atl::NIL,
	avl::Image& diagGradientImage,
	atl::Array<atl::Array<avl::Segment2D>>& diagScheduledScanSegments
)

Parameters

Name	Type	Default	Description
inImage	const Image&		Input image
inRoi	Optional<const ShapeRegion&>	NIL	Region of interest
inRoiAlignment	Optional<const CoordinateSystem2D&>	NIL	Adjusts the region of interest to the position of the inspected object
inBarcodeParams	const BarcodeParams&		Specification of barcode that can be detected
inDetectionParams	const BarcodeDetectionParams&		Parameters of the barcode detection algorithm
outBarcode	Conditional<Barcode>&		A barcode that has been correctly detected and decoded
outBarcodeCandidates	Optional<Array<Rectangle2D>&>	NIL	Places with high gradient values that are further investigated
outAlignedRoi	Optional<ShapeRegion&>	NIL	Input ROI after transformation (in the image coordinates)
diagGradientImage	Image&		Image of gradient directions
diagScheduledScanSegments	Array<Array<Segment2D>>&		Scheduled scan segments

Optional Outputs

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

Description

This filter detects a barcode present in the input image and reads its content.

Hints

Connect inImage with the output of your image acquisition filter.
Select inBarcodeParams.Format according to the type of codes you want to read. If you choose the wrong format, the codes will not be recognized. Setting its value to Auto can increase the computation time considerably. Furthermore, the Auto value causes detection of UPC-A codes as EAN-13 codes.

If the image resolution is high, set inBarcodeParams.MaxModuleSize accordingly or resize/downsample the input image.

Examples

Rotated barcode.

Low quality barcode printed on plastic foil.

Barcode on package wrapped in plastic foil.

Barcode in a blurry image.

Barcode on standard 330ml can.

Barcode on reflective and wrapped surface.

EAN-13 with add-on 2 used to indicate a book edition.

EAN-13 with add-on 5 to give a suggestion for the price.

Remarks

Minimal bar width requirement

To provide precise detection of the barcode width of the thinnest bar should be at least 1.5 pixels.

Depending on the barcode format guard or start/end code patterns must be readable.

Pharmacode usage

The pharmacode barcode type can be read correctly in both directions. To get results from both directions use a Pharmacode and PharmacodeInversed barcode types.

Before decoding a Pharmacode the code orientation angle is normalized to a range from -45° to 135° what makes the code decoding more stable

Results of reading using a different Pharmacode directions: Pharmacode = 23 and PharmacodeInversed = 16.

Using a relative coordinate systems

Read more about Local Coordinate Systems in Machine Vision Guide: Local Coordinate Systems.

Hardware Acceleration

This operation supports automatic parallelization for multicore and multiprocessor systems.