←Select platform

ReadBarcodes(RasterImage,LogicalRectangle,Int32,BarcodeSymbology[]) Method

Summary

Read multiple barcodes from an image with symbologies from a specified group the default options.

Syntax

Java

Objective-C

WinRT C#

C++

public [Leadtools.Barcode.BarcodeData[]](barcodedata.html) ReadBarcodes(  
   Leadtools.RasterImage image, 
   Leadtools.Forms.LogicalRectangle searchBounds, 
   int maximumBarcodes, 
   Leadtools.Barcode.BarcodeSymbology[] symbologies 
)

Public Overloads Function ReadBarcodes( _ 
   ByVal image As Leadtools.RasterImage, _ 
   ByVal searchBounds As Leadtools.Forms.LogicalRectangle, _ 
   ByVal maximumBarcodes As Integer, _ 
   ByVal symbologies() As Leadtools.Barcode.BarcodeSymbology _ 
) As Leadtools.Barcode.BarcodeData()

public [Leadtools.Barcode.BarcodeData[]](barcodedata.html) ReadBarcodes(  
   Leadtools.RasterImage image, 
   Leadtools.Forms.LogicalRectangle searchBounds, 
   int maximumBarcodes, 
   Leadtools.Barcode.BarcodeSymbology[] symbologies 
)

- (nullable NSArray<LTBarcodeData *> *)readBarcodes:(LTRasterImage *)image  
                                       searchBounds:(LeadRect)searchBounds  
                                    maximumBarcodes:(NSUInteger)maximumBarcodes  
                                        symbologies:(nullable NSArray<NSNumber *> *)symbologies  
                                              error:(NSError **)error

public BarcodeData[] readBarcodes( 
  RasterImage image,  
  LeadRect searchBounds,  
  int maximumBarcodes,  
  BarcodeSymbology[] symbologies 
)

 function Leadtools.Barcode.BarcodeReader.ReadBarcodes(RasterImage,LogicalRectangle,Int32,BarcodeSymbology[])(  
   image , 
   searchBounds , 
   maximumBarcodes , 
   symbologies  
)

public: 
Leadtools.Barcode.array<BarcodeData^>^ ReadBarcodes(  
   Leadtools.RasterImage^ image, 
   Leadtools.Forms.LogicalRectangle searchBounds, 
   int maximumBarcodes, 
   Leadtools.Barcode.array<BarcodeSymbology>^ symbologies 
)

Parameters

image
A RasterImage object that contains the image data. Must not be null (Nothing in VB).

searchBounds
A LogicalRectangle that specifies the region of interest area in the image where the barcodes search and detection is performed. You can specify LogicalRectangle.Empty to indicate that the search must be performed on the whole image.

maximumBarcodes
An Int32 that specifies the maximum number of barcodes to return. Must be a value greater than or equal to 0. The value of 0 means all barcodes.

symbologies
An array of BarcodeSymbology enumeration members that specifies the barcode symbologies (types) to search for.

Return Value

An array of BarcodeData objects or derived classes that contains the symbology, data, location and any rotation angle for each barcode found. If no barcodes can be found, then this method will return an empty array (Length equals to 0).

Remarks

Use this method if you want to read multiple barcodes of the same or multiple symbologies from an image. For example, to read all UPC and QR barcodes in the image, use an array of BarcodeSymbology.UPC-A, BarcodeSymbology.UPC-E and BarcodeSymbology.QR.

LEADTOOLS barcode read engine is optimized for speed and can search for multiple similar symbologies at the same time. This method simply returns the first barcode that is detected correctly using the symbologies and current options.

The ReadSymbology event will occur before and after attempting to read any symbology. The read options being used whether the default or specified will be set in the BarcodeReadSymbologyEventArgs.Options property of the event data.

This method will use the default read options set in this BarcodeReader for all the items in symbologies.

If symbologies is null (Nothing in VB), then this method will use all the currently available symbologies. If this parameter contains an empty array, then no barcode will be detected and an empty array will be returned.

The BarcodeReader provides the following barcode read methods:

Method	Description
ReadBarcode(RasterImage image, LogicalRectangle searchBounds, BarcodeSymbology symbology) and ReadBarcode(RasterImage image, LogicalRectangle searchBounds, BarcodeSymbology symbology, BarcodeReadOptions options)	Read one barcode from an image with specified symbology and default or specific options. Use these methods if you want to read a single barcode from the image, for example, a QR symbol by specifying BarcodeSymbology.QR or if you want to read any barcode found regardless of its type by using BarcodeSymbology.Unknown.
ReadBarcode(RasterImage image, LogicalRectangle searchBounds, BarcodeSymbology[] symbologies) and ReadBarcode(RasterImage image, LogicalRectangle searchBounds, BarcodeSymbology[] symbologies, BarcodeReadOptions[] options)	Read one barcode from an image with a symbology from a specified group and default or specific options. Use these methods if you want to read a single barcode from a known group. For example, to read a barcode that can be of any UPC type, pass an array of BarcodeSymbology.UPCA and BarcodeSymbology.UPCE.
ReadBarcodes(RasterImage image, LogicalRectangle searchBounds, int maximumBarcodes, BarcodeSymbology[] symbologies) and ReadBarcodes(RasterImage image, LogicalRectangle searchBounds, int maximumBarcodes, BarcodeSymbology[] symbologies, BarcodeReadOptions[] options)	Read multiple barcodes from an image with symbologies from a specified group and default or specific options. Use these methods if you want to read multiple barcodes of the same or multiple symbologies.

Example

This example shows how to use this method to read multiple barcodes from a specific group from an image.

Silverlight C#

Silverlight VB

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Forms; 
using Leadtools.Barcode; 
using Leadtools.ImageProcessing; 
 
public void BarcodeReader_ReadBarcodeExample5() 
{ 
   string imageFileName = Path.Combine(LEAD_VARS.ImagesDir, "Barcode2.tif"); 
 
   // Create a Barcode engine 
   BarcodeEngine engine = new BarcodeEngine(); 
 
   // Get the Barcode reader instance 
   BarcodeReader reader = engine.Reader; 
 
   using (RasterCodecs codecs = new RasterCodecs()) 
   { 
      using (RasterImage image = codecs.Load(imageFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1)) 
      { 
         // We are interested in QR and Datamatrix barcodes only 
         BarcodeSymbology[] symbologies = 
         { 
            BarcodeSymbology.QR, 
            BarcodeSymbology.Datamatrix 
         }; 
 
         // Tead the barcodes 
         Console.WriteLine("Reading only QR and Datamatrix barcodes"); 
         BarcodeData[] barcodes = reader.ReadBarcodes(image, LogicalRectangle.Empty, 0, symbologies); 
 
         // Show the location and data if found for each barcode 
         foreach (BarcodeData barcode in barcodes) 
         { 
            // This will find the barcode and print its information now 
            Console.WriteLine("Found a {0} barcode at {1}, data:\n{2}", barcode.Symbology, barcode.Bounds, barcode.Value); 
         } 
      } 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images"; 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.Forms 
Imports Leadtools.Barcode 
Imports Leadtools.ImageProcessing 
 
Public Sub BarcodeReader_ReadBarcodeExample5() 
   Dim imageFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Barcode2.tif") 
 
   ' Create a Barcode engine 
   Dim engine As New BarcodeEngine() 
 
   ' Get the Barcode reader instance 
   Dim reader As BarcodeReader = engine.Reader 
 
   Using codecs As New RasterCodecs() 
      Using image As RasterImage = codecs.Load(imageFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1) 
         ' We are interested in QR and Datamatrix barcodes only 
         Dim symbologies() As BarcodeSymbology = 
         { 
            BarcodeSymbology.QR, 
            BarcodeSymbology.Datamatrix 
         } 
 
         ' Tead the barcodes 
         Console.WriteLine("Reading only QR and Datamatrix barcodes") 
         Dim barcodes() As BarcodeData = reader.ReadBarcodes(image, LogicalRectangle.Empty, 0, symbologies) 
 
         ' Show the location and data if found for each barcode 
         For Each barcode As BarcodeData In barcodes 
            ' This will find the barcode and print its information now 
            Console.WriteLine("Found a {0} barcode at {1}, data:\n{2}", barcode.Symbology, barcode.Bounds, barcode.Value) 
         Next 
      End Using 
   End Using 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images" 
End Class

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Forms; 
using Leadtools.Barcode; 
using Leadtools.ImageProcessing; 
using Leadtools.Examples; 
 
public void BarcodeReader_ReadBarcodeExample5(RasterImage image) 
{ 
   // Create a Barcode engine 
   BarcodeEngine engine = new BarcodeEngine(); 
 
   // Get the Barcode reader instance 
   BarcodeReader reader = engine.Reader; 
 
   RasterCodecs codecs = new RasterCodecs(); 
 
   // We are interested in QR and Datamatrix barcodes only 
   BarcodeSymbology[] symbologies = 
   { 
      BarcodeSymbology.QR, 
      BarcodeSymbology.Datamatrix 
   }; 
 
   // Tead the barcodes 
   Console.WriteLine("Reading only QR and Datamatrix barcodes"); 
   BarcodeData[] barcodes = reader.ReadBarcodes(image, LogicalRectangle.Empty, 0, symbologies); 
 
   // Show the location and data if found for each barcode 
   foreach (BarcodeData barcode in barcodes) 
   { 
      // This will find the barcode and print its information now 
      Console.WriteLine("Found a {0} barcode at {1}, data:\n{2}", barcode.Symbology, barcode.Bounds, barcode.Value); 
   } 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.Forms 
Imports Leadtools.Barcode 
Imports Leadtools.ImageProcessing 
Imports Leadtools.ImageProcessing.Color 
 
Public Sub BarcodeReader_ReadBarcodeExample5(ByVal image As RasterImage) 
   ' Create a Barcode engine 
   Dim engine As BarcodeEngine = New BarcodeEngine() 
 
   ' Get the Barcode reader instance 
   Dim reader As BarcodeReader = engine.Reader 
 
   Dim codecs As RasterCodecs = New RasterCodecs() 
 
   ' We are interested in QR and Datamatrix barcodes only 
   Dim symbologies As BarcodeSymbology() = {BarcodeSymbology.QR, BarcodeSymbology.Datamatrix} 
 
   ' Tead the barcodes 
   Console.WriteLine("Reading only QR and Datamatrix barcodes") 
   Dim barcodes As BarcodeData() = reader.ReadBarcodes(image, LogicalRectangle.Empty, 0, symbologies) 
 
   ' Show the location and data if found for each barcode 
   For Each barcode As BarcodeData In barcodes 
      ' This will find the barcode and print its information now 
      Console.WriteLine("Found a {0} barcode at {1}, data:" & Constants.vbLf & "{2}", barcode.Symbology, barcode.Bounds, barcode.Value) 
   Next barcode 
End Sub