You are here: Start » Function Reference » Computer Vision » Barcodes » RecognizeBarcode

RecognizeBarcode

Header:	FIL.h
Namespace:	fil
Module:	Barcodes

Extracts information from a barcode located on the input image at a given position.

Applications: Most often used after a barcode detection filter.

Syntax

void fil::RecognizeBarcode
(
	const fil::Image& inImage,
	const fil::Rectangle2D& inBarcodePosition,
	ftl::Optional<const fil::CoordinateSystem2D&> inBarcodePositionAlignment,
	const fil::BarcodeParams& inBarcodeParams,
	const int inScanCount,
	const int inScanWidth,
	const float inMinEdgeStrength,
	ftl::Conditional<fil::Barcode>& outBarcode,
	ftl::Optional<fil::Rectangle2D&> outAlignedBarcodePosition = ftl::NIL,
	ftl::Array<fil::Segment2D>& diagScheduledScanSegments
)

Parameters

Name	Type	Range	Default	Description
inImage	const Image&			Input image
inBarcodePosition	const Rectangle2D&			Position of the input image in which the barcode is located
inBarcodePositionAlignment	Optional<const CoordinateSystem2D&>		NIL	Adjusts the barcode rectangle to the position of the inspected object
inBarcodeParams	const BarcodeParams&			Specification of barcode that can be read
inScanCount	const int	1 -	5	Number of parallel scans run until first successful read
inScanWidth	const int	1 -	5	Width of the single scan
inMinEdgeStrength	const float	0.0 -	5.0f	Minimal strength of an extracted edge
outBarcode	Conditional<Barcode>&			Decoded barcode or nothing if all of the scans failed
outAlignedBarcodePosition	Optional<Rectangle2D&>		NIL
diagScheduledScanSegments	Array<Segment2D>&			Scheduled scan segments

Optional Outputs

The computation of following outputs can be switched off by passing value ftl::NIL to these parameters: outAlignedBarcodePosition.

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.

Examples

Rotated barcode.

Low quality barcode printed on plastic foil.

Barcode on package wrapped in plastic foil.

Barcode on 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.