Halftones Property (Device)

In This Topic

Gets or sets the halftones for bit depth reduction of images for current scan session.

Syntax

Visual Basic
C#
Managed Extensions for C++
C++/CLI

'Declaration

Public Property Halftones As String

public string Halftones { get; set; }

public: __property string* get_Halftones();
public: __property void set_Halftones(
   string* value
);

public:
property string^ Halftones {
   string^ get();
   void set(string^ value);
}

Exceptions

Exception	Description
TwainInvalidStateException	Thrown if device is in wrong state.
TwainDeviceCapabilityException	Thrown if device does not support capability.
DebuggerException	Thrown if the .NET debugger is used and the function evaluation requires all threads to run.

Remarks

Call this property only when device is opened (State == DeviceState.Opened).

Supported values of halftones can be received by the GetSupportedHalftones method.

Important: Value of the BitDepthReductionMode property must be set to the BitDepthReductionMode.Halftones value before usage of this property.

Example

This C#/VB.NET code shows how to apply halftones to images acquired from the device.

VB.NET


Public Sub ScanPaletteImageWithHalftones(device As Vintasoft.Twain.Device)
        device.ShowUI = False
        device.DisableAfterAcquire = True

        device.Open()
        device.PixelType = Vintasoft.Twain.PixelType.Gray
        device.BitDepthReductionMode = Vintasoft.Twain.BitDepthReductionMode.Halftones
        device.Halftones = "Dither Pattern 1"
        device.UnitOfMeasure = Vintasoft.Twain.UnitOfMeasure.Inches
        device.Resolution = New Vintasoft.Twain.Resolution(200F, 200F)

        device.Acquire()
End Sub


public void ScanPaletteImageWithHalftones(Vintasoft.Twain.Device device)
{
    device.ShowUI = false;
    device.DisableAfterAcquire = true;

    device.Open();
    device.PixelType = Vintasoft.Twain.PixelType.Gray;
    device.BitDepthReductionMode = Vintasoft.Twain.BitDepthReductionMode.Halftones;
    device.Halftones = "Dither Pattern 1";
    device.UnitOfMeasure = Vintasoft.Twain.UnitOfMeasure.Inches;
    device.Resolution = new Vintasoft.Twain.Resolution(200f, 200f);

    device.Acquire();
}

Requirements

Target Platforms: .NET 9; .NET 8; .NET 7; .NET 6; .NET Framework 4.8, 4.7, 4.6, 4.5, 4.0, 3.5

Reference

Device Class
Device Members

GetSupportedHalftones
Open

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