VintaSoft Twain .NET SDK 14.1: Documentation for .NET developer
Vintasoft.Twain Namespace / Device Class / Contrast Property
Syntax Exceptions Remarks Example Requirements SeeAlso
In This Topic
    Contrast Property (Device)
    In This Topic
    Gets or sets the contrast of gray/palette/color images for current scan session.
    Syntax
    'Declaration
    
    Public Property Contrast As Single
    
    
    public float Contrast { get; set; }
    
    
    public: __property float get_Contrast();
    public: __property void set_Contrast(
    float value
    );
    public:
    property float Contrast { float get(); void set(float value); }
    Exceptions
    ExceptionDescription
    Thrown if device is in wrong state.
    Thrown if device does not support capability.
    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 brightness can be received by the GetSupportedContrastValues method.

    This property has effect only for gray/palette/color images. Threshold property must be used for black-white images.

    Example

    This C#/VB.NET code shows how to adjust brightness/contrast and acquire color images from the device.

    
    Public Sub ScanColorImageWithBrightness(ByVal device As Vintasoft.Twain.Device)
        device.ShowUI = False
        device.DisableAfterAcquire = True
    
        device.Open()
        device.PixelType = Vintasoft.Twain.PixelType.RGB
        device.UnitOfMeasure = Vintasoft.Twain.UnitOfMeasure.Inches
        device.Resolution = New Vintasoft.Twain.Resolution(300.0F, 300.0F)
        device.Brightness = 128.0F
        device.Contrast = 0
    
        device.Acquire()
    End Sub
    
    
    
    public void ScanColorImageWithBrightness(Vintasoft.Twain.Device device)
    {
        device.ShowUI = false;
        device.DisableAfterAcquire = true;
    
        device.Open();
        device.PixelType = Vintasoft.Twain.PixelType.RGB;
        device.UnitOfMeasure = Vintasoft.Twain.UnitOfMeasure.Inches;
        device.Resolution = new Vintasoft.Twain.Resolution(300f, 300f);
        device.Brightness = 128f;
        device.Contrast = 0;
    
        device.Acquire();
    }
    
    

    Requirements

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

    See Also