EnablePreprocessing Property

Summary

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

Syntax

Objective-C

C++/CLI

Python

public bool EnablePreprocessing { get; set; }

@property (nonatomic, assign) BOOL enablePreprocessing;

public:  
   property bool EnablePreprocessing 
   { 
      bool get() 
      void set(bool value) 
   }

EnablePreprocessing # get and set (DatamatrixBarcodeReadOptions)

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.

Remarks

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 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.

Example

Java

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Barcode; 
using Leadtools.ImageProcessing; 
 
 
public void DatamatrixBarcode_Example() 
{ 
   string imageFileName = Path.Combine(LEAD_VARS.ImagesDir, "MyDatamatrixBarcodes.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 two Datamatrix barcodes, a square and a rectangle one 
      WriteBarcode(engine.Writer, image, DatamatrixBarcodeSymbolSize.Size16X36, "Datamatrix1 16x36", false); 
      WriteBarcode(engine.Writer, image, DatamatrixBarcodeSymbolSize.Size132X132, "Datamatrix2 132x132", true); 
 
      // 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 only square symbols, should only read the first barcode 
         ReadBarcodes(engine.Reader, image, true); 
 
         // Read all symbols, should read both barcodes 
         ReadBarcodes(engine.Reader, image, false); 
      } 
   } 
} 
 
private void WriteBarcode(BarcodeWriter writer, RasterImage image, DatamatrixBarcodeSymbolSize symbolSize, string value, bool topLeft) 
{ 
   // Create the barcode data 
   DatamatrixBarcodeData barcode = BarcodeData.CreateDefaultBarcodeData(BarcodeSymbology.Datamatrix) as DatamatrixBarcodeData; 
   barcode.SymbolSize = symbolSize; 
   barcode.Value = value; 
   barcode.Symbology= BarcodeSymbology.Datamatrix; 
 
   // We will use the alignment to position the barcodes, so use all of the image 
   barcode.Bounds = new LeadRect(0, 0, image.ImageWidth, image.ImageHeight); 
 
   // Set the write options 
   DatamatrixBarcodeWriteOptions options = new DatamatrixBarcodeWriteOptions(); 
 
   if (topLeft) 
   { 
      options.HorizontalAlignment = BarcodeAlignment.Near; 
      options.VerticalAlignment = BarcodeAlignment.Near; 
   } 
   else 
   { 
      options.HorizontalAlignment = BarcodeAlignment.Far; 
      options.VerticalAlignment = BarcodeAlignment.Far; 
   } 
 
   options.DisableCompression = false; 
   options.GroupNumber = 0; 
   options.GroupTotal = 0; 
   options.FileIdNumberLowByte = 1; 
   options.FileIdNumberHighByte = 1; 
   options.XModule = 30; 
   options.HRItoGS1 = false; 
 
   // Write it 
   Console.WriteLine("Writing barcode with symbol size: {0} and Data: {1}", symbolSize, value); 
   writer.WriteBarcode(image, barcode, options); 
} 
 
private void ReadBarcodes(BarcodeReader reader, RasterImage image, bool squareOnly) 
{ 
   // Setup read options 
   DatamatrixBarcodeReadOptions options = new DatamatrixBarcodeReadOptions(); 
   options.ReadSquareSymbolsOnly = squareOnly; 
   options.EnableDoublePass = false; 
   options.EnableDoublePassIfSuccess = false; 
   options.EnableInvertedSymbols = false; 
   options.EnableFastMode = true; 
   options.EnableSmallSymbols = true; 
   options.EnablePreprocessing = true; 
   options.GS1toHRI = false; 
 
   Console.WriteLine("Reading Datamatrix barcodes with ReadSquareSymbolsOnly set to {0}", squareOnly); 
   BarcodeData[] barcodes = reader.ReadBarcodes(image, LeadRect.Empty, 0, new BarcodeSymbology[] { BarcodeSymbology.Datamatrix }, new BarcodeReadOptions[] { options }); 
   Console.WriteLine("{0} barcodes found:", barcodes.Length); 
   foreach (DatamatrixBarcodeData barcode in barcodes) 
   { 
      Console.WriteLine(" At {0}, symbol size: {1} data: {2} and symbology: {3}", barcode.Bounds, barcode.SymbolSize, barcode.Value, barcode.Symbology); 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}

 
import java.io.File; 
import java.io.IOException; 
 
import org.junit.*; 
import org.junit.runner.JUnitCore; 
import org.junit.runner.Result; 
import org.junit.runner.notification.Failure; 
import static org.junit.Assert.*; 
 
import leadtools.*; 
import leadtools.barcode.*; 
import leadtools.codecs.*; 
 
 
public void datamatrixBarcodeExample() { 
   final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
   String imageFileName = combine(LEAD_VARS_IMAGES_DIR, "MyDatamatrixBarcodes.tif"); 
   BarcodeEngine engine = new BarcodeEngine(); 
 
   // Create the image to write the barcodes to 
   int resolution = 300; 
   RasterImage image = RasterImage.create( 
      (int) (8.5 * resolution),  
      (int) (11.0 * resolution),  
      1,  
      resolution, 
      RasterColor.fromKnownColor(RasterKnownColor.WHITE) 
   ); 
 
   // Write two Datamatrix barcodes, a square and a rectangle one 
   writeBarcode(engine.getWriter(), image, DatamatrixBarcodeSymbolSize.SIZE16X36, "Datamatrix1 16x36", false); 
   writeBarcode(engine.getWriter(), image, DatamatrixBarcodeSymbolSize.SIZE132X132, "Datamatrix2 132x132", true); 
 
   // Save the image 
   RasterCodecs codecs = new RasterCodecs(); 
   codecs.save(image, imageFileName, RasterImageFormat.CCITT_GROUP4, 1); 
 
   // Now read the barcodes again 
   image = codecs.load(imageFileName); 
 
   // Read only square symbols, should only read the first barcode 
   readBarcodes(engine.getReader(), image, true); 
 
   // Read all symbols, should read both barcodes 
   readBarcodes(engine.getReader(), image, false); 
 
   // cleanup 
   image.dispose(); 
   codecs.dispose(); 
} 
 
// Create the barcode data 
private void writeBarcode(BarcodeWriter writer, RasterImage image, DatamatrixBarcodeSymbolSize symbolSize, String value, boolean topLeft) { 
   DatamatrixBarcodeData barcode = (DatamatrixBarcodeData) BarcodeData.createDefaultBarcodeData(BarcodeSymbology.DATAMATRIX); 
   barcode.setSymbolSize(symbolSize); 
   barcode.setValue(value); 
   barcode.setSymbology(BarcodeSymbology.DATAMATRIX); 
 
   // We will use the alignment to position the barcodes, so use all of the image 
   barcode.setBounds(new LeadRect(0, 0, image.getImageWidth(), image.getImageHeight())); 
 
   // Set the write options 
   DatamatrixBarcodeWriteOptions options = new DatamatrixBarcodeWriteOptions(); 
 
   if (topLeft) { 
 
      options.setHorizontalAlignment(BarcodeAlignment.NEAR); 
      options.setVerticalAlignment(BarcodeAlignment.NEAR); 
 
   } else { 
 
      options.setHorizontalAlignment(BarcodeAlignment.FAR); 
      options.setVerticalAlignment(BarcodeAlignment.FAR); 
 
   } 
 
   options.setDisableCompression(false); 
   options.setGroupNumber(0); 
   options.setGroupTotal(0); 
   options.setFileIdNumberLowByte((byte) 1); 
   options.setFileIdNumberHighByte((byte) 1); 
   options.setXModule(30); 
   options.setHRItoGS1(false); 
 
   // Write it 
   System.out.printf("Writing barcode with symbol size: %1s and Data: %2s%n", symbolSize, value); 
   writer.writeBarcode(image, barcode, options); 
} 
 
// Setup read options 
private void readBarcodes(BarcodeReader reader, RasterImage image, boolean squareOnly) { 
   DatamatrixBarcodeReadOptions options = new DatamatrixBarcodeReadOptions(); 
   options.setReadSquareSymbolsOnly(squareOnly); 
   options.setEnableDoublePass(false); 
   options.setEnableDoublePassIfSuccess(false); 
   options.setEnableInvertedSymbols(false); 
   options.setEnableFastMode(true); 
   options.setEnableSmallSymbols(true); 
   options.setEnablePreprocessing(true); 
   options.setGS1toHRI(false); 
 
   System.out.printf("Reading Datamatrix barcodes with ReadSquareSymbolsOnly set to %1s%n", squareOnly); 
   BarcodeData[] barcodes = reader.readBarcodes(image, LeadRect.getEmpty(), 0, 
         new BarcodeSymbology[] { BarcodeSymbology.DATAMATRIX }, new BarcodeReadOptions[] { options }); 
   System.out.printf("%s barcodes found:%n", barcodes.length); 
 
   for (BarcodeData barcode : barcodes) { 
 
      System.out.printf(" At %1s, symbol size: %2s data: %3s and symbology: %4s", barcode.getBounds(), 
            barcode.getData(), barcode.getValue(), barcode.getSymbology()); 
 
   } 
}

Requirements

Target Platforms

Reference

DatamatrixBarcodeReadOptions Class

DatamatrixBarcodeReadOptions Members

Leadtools.Barcode Namespace

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Help Version 23.0.2024.2.29

Leadtools.Barcode Assembly

Introduction

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Namespaces

Leadtools.Barcode Namespace

Assemblies