ConvertTo1Bpp(Int32,Byte) Method

In This Topic

Converts a GdPicture image to a 1-bit BW indexed color image specifying a threshold value. The color table has 2 entries: 1 Black & 1 White.

Syntax

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

'Declaration
 
Public Overloads Function ConvertTo1Bpp( _
   ByVal ImageID As Integer, _
   ByVal Threshold As Byte _
) As GdPictureStatus

public GdPictureStatus ConvertTo1Bpp( 
   int ImageID,
   byte Threshold
)

public function ConvertTo1Bpp( 
    ImageID: Integer;
    Threshold: Byte
): GdPictureStatus;

public function ConvertTo1Bpp( 
   ImageID : int,
   Threshold : byte
) : GdPictureStatus;

public: GdPictureStatus ConvertTo1Bpp( 
   int ImageID,
   byte Threshold
)

public:
GdPictureStatus ConvertTo1Bpp( 
   int ImageID,
   byte Threshold
)

Parameters

ImageID: GdPicture image identifier.
Threshold: Value between [1 and 255]. Pixels values less than Threshold will be turned black, values equal to or larger till be turned white. If you do not know what to choose, select 160 which is the suggested value.

Return Value

A member of the GdPictureStatus enumeration.

Remarks

This method requires the Image Documents component to run.

The pixel value of colored pixels is computed via the following formula: PixValue = (0.2126F * r + 0.7152F * g + 0.0722F * b)

Example

Converts selected image to a 1-bit BW indexed color image, and saves result into a TIF file.

using (GdPictureImaging gdpictureImaging = new GdPictureImaging())
{
    // Open an image file. An empty string allows the control to prompt for selecting a file.
    int imageID = gdpictureImaging.CreateGdPictureImageFromFile("");
 
    gdpictureImaging.ConvertTo1Bpp(imageID, 160);
    gdpictureImaging.SaveAsTIFF(imageID, "output.tif", TiffCompression.TiffCompressionAUTO);
 
    // Release used resources.
    gdpictureImaging.ReleaseGdPictureImage(imageID);
}

Reference

GdPictureImaging Class
GdPictureImaging Members
Overload List
FxBlackNWhite(Int32,BitonalReduction) Method
FxBlackNWhiteT Method