EnableDoublePass Property (PDF417BarcodeReadOptions)

[DisplayNameAttribute("Enable double pass")]
[CategoryAttribute("			Options")]
[DefaultValueAttribute()]
[DescriptionAttribute("If no barcodes of this symbology is found, auto pre-process the image and then re-scan")]
public bool EnableDoublePass {get; set;}

'Declaration
 
<DisplayNameAttribute("Enable double pass")>
<CategoryAttribute("			Options")>
<DefaultValueAttribute()>
<DescriptionAttribute("If no barcodes of this symbology is found, auto pre-process the image and then re-scan")>
Public Property EnableDoublePass As Boolean

'Usage
 
Dim instance As PDF417BarcodeReadOptions
Dim value As Boolean
 
instance.EnableDoublePass = value
 
value = instance.EnableDoublePass

[DisplayNameAttribute("Enable double pass")]
[CategoryAttribute("			Options")]
[DefaultValueAttribute()]
[DescriptionAttribute("If no barcodes of this symbology is found, auto pre-process the image and then re-scan")]
public bool EnableDoublePass {get; set;}

ObjectiveC Syntax

Java Syntax

DisplayNameAttribute("Enable double pass")
CategoryAttribute("			Options")
DefaultValueAttribute()
DescriptionAttribute("If no barcodes of this symbology is found, auto pre-process the image and then re-scan")
 get_EnableDoublePass();
set_EnableDoublePass(value); 

[DisplayNameAttribute("Enable double pass")]
[CategoryAttribute("			Options")]
[DefaultValueAttribute()]
[DescriptionAttribute("If no barcodes of this symbology is found, auto pre-process the image and then re-scan")]
public:
property bool EnableDoublePass {
   bool get();
   void set (    bool value);
}

Property Value

When reading 2D barcodes, LEADTOOLS can perform internal auto pre-processing on the image and try again if the engine cannot detect the required barcode . This may take extra processing and increase the barcode detection time. Therefore, it is not recommended to always have it enabled except in certain situations:

• The application is reading barcodes of this type exclusively. For example, a dedicated PDF417 reader. When always reading barcodes is more important than recognition speed.

• The application uses barcode detection on a server. In this case, 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 result back due to network latency. Hence, it makes sense to turn this feature on in this situation.

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

• The LEADTOOLS .NET C# and VB Barcode Demo leaves the option disabled by default. When the user tries to read a barcode of this type and the engine cannot find it, it will then ask the user if they want to turn this feature on and try again. An approach like that (or an automated one: read, if fails, enable and read again) can also be used.

For an example, refer to PDF417BarcodeReadOptions.

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

PDF417BarcodeReadOptions Class
PDF417BarcodeReadOptions Members