←Select platform

EnablePreprocessing Property


Enable applying auto segmentation and deep auto pre-processing to the image then re-scanning if no barcodes of this symbology are found.

public bool EnablePreprocessing { get; set; } 
@property (nonatomic, assign) BOOL enablePreprocessing; 
   property bool EnablePreprocessing 
      bool get() 
      void set(bool value) 
EnablePreprocessing # get and set (OneDBarcodeReadOptions) 

Property Value

true to apply auto segmentation and deep auto pre-processing to the image then re-scanning if no barcodes of this symbology are found; otherwise, false. The default value is false.


When reading 2D barcodes, LEADTOOLS can perform internal auto preprocessing and segmentation on the image and try again if the engine cannot detect the barcode required. This may take extra processing and increase the barcode detection time. Therefore, it is best to set EnablePreprocessing to true only in certain situations, as follows:

  • The application is reading barcodes of this type exclusively (for example, a dedicated barcode reader is being used). In this case, reading the barcodes is always more important than recognition speed.

  • The application uses barcode detection on a server. Due to network latency, the time spent on the actual barcode detection is most probably less than the time required to send the image to the server and get the results back. Thus, it makes sense to enable pre-processing in this situation.

  • The images provided have a small resolution (DPI) or are known to come from a source that does not always provide clean images (for example, a Fax machine or a Scanner). Enabling pre-processing here ensures that the barcodes can be read regardless of the quality of the input image.

The LEADTOOLS .NET C# Barcode demos leave pre-processing disabled by default. If the engine tries to read a barcode of this type but cannot find it, it will then ask the user if EnablePreprocessing should be enabled and reading be retried. An approach like that (or an automated one: Read. If failure, enable and read again) can also be used.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Barcode; 
using Leadtools.ImageProcessing; 
public void OneDBarcode_Example() 
   string imageFileName = Path.Combine(LEAD_VARS.ImagesDir, "MyOneDBarcodes.tif"); 
   BarcodeEngine engine = new BarcodeEngine(); 
   // Create the image to write the barcodes to 
   int resolution = 300; 
   using (RasterImage image = RasterImage.Create((int)(8.5 * resolution), (int)(11.0 * resolution), 1, resolution, RasterColor.FromKnownColor(RasterKnownColor.White))) 
      // Write a POSTNET and a PLANET barcodes 
      WriteBarcode(engine.Writer, image, BarcodeSymbology.UPCA, "01234567890", new LeadRect(10, 100, 400, 200)); 
      WriteBarcode(engine.Writer, image, BarcodeSymbology.Code128, "Code 128", new LeadRect(10, 400, 400, 200)); 
      WriteBarcode(engine.Writer, image, BarcodeSymbology.Code11, "124578", new LeadRect(10, 700, 400, 200)); 
      // Save the image 
      using (RasterCodecs codecs = new RasterCodecs()) 
         codecs.Save(image, imageFileName, RasterImageFormat.CcittGroup4, 1); 
   // Now read the barcodes again 
   using (RasterCodecs codecs = new RasterCodecs()) 
      using (RasterImage image = codecs.Load(imageFileName)) 
         // Read the UPC-A barcode 
         ReadBarcodes(engine.Reader, image, BarcodeSymbology.UPCA); 
         // Read the Code 128 barcode 
         ReadBarcodes(engine.Reader, image, BarcodeSymbology.Code128); 
         // Read the Code 11 barcode 
         ReadBarcodes(engine.Reader, image, BarcodeSymbology.Code11); 
private void WriteBarcode(BarcodeWriter writer, RasterImage image, BarcodeSymbology symbology, string value, LeadRect bounds) 
   // Create the barcode data 
   BarcodeData barcode = new BarcodeData(symbology, value); 
   barcode.Bounds = bounds; 
   // Set the write options 
   OneDBarcodeWriteOptions options = new OneDBarcodeWriteOptions(); 
   options.TextPosition = BarcodeOutputTextPosition.Default; 
   options.UseXModule = false; 
   options.XModule = 30; 
   options.EnableErrorCheck = false; 
   options.SetGS1DatabarLinkageBit = false; 
   options.WriteTruncatedGS1Databar = false; 
   options.Code128TableEncoding = Code128BarcodeTableEncoding.Auto; 
   options.Code11CheckDigitType = Code11BarcodeCheckDigitType.CDigit; 
   options.MSIModuloType = MSIBarcodeModuloType.Modulo10; 
   // Write it 
   Console.WriteLine("Writing {0} barcode with data: {1}", symbology, value); 
   writer.WriteBarcode(image, barcode, options); 
private void ReadBarcodes(BarcodeReader reader, RasterImage image, BarcodeSymbology symbology) 
   // Setup read options 
   OneDBarcodeReadOptions options = new OneDBarcodeReadOptions(); 
   options.SearchDirection = BarcodeSearchDirection.Horizontal; 
   options.EnableFastMode = true; 
   options.Granularity = 9; 
   options.MinimumStringLength = 3; 
   options.MaximumStringLength = 0; 
   options.WhiteLinesNumber = 3; 
   options.ReturnCheckDigit = BarcodeReturnCheckDigit.Default; 
   options.EnableErrorCheck = false; 
   options.AvoidCorruptedBlocks = false; 
   options.AllowPartialRead = false; 
   options.Code11CheckDigitType = Code11BarcodeCheckDigitType.CDigit; 
   options.MSIModuloType = MSIBarcodeModuloType.Modulo10; 
   options.CalculateBarWidthReduction = true; 
   options.Code39Extended = false; 
   options.EnableDoublePass = false; 
   options.EnablePreprocessing = false; 
   options.ResizeSmall1D = false; 
   Console.WriteLine("Reading {0} barcodes", symbology); 
   BarcodeData barcode = reader.ReadBarcode(image, LeadRect.Empty, symbology, options); 
   if (barcode != null) 
      Console.WriteLine(" At {0}, data: {1}", barcode.Bounds, barcode.Value); 
      Console.WriteLine(" Not found"); 
static class LEAD_VARS 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 

Target Platforms

Help Version 22.0.2023.5.9
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.

Leadtools.Barcode Assembly

Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.