TIEBitmap.BlackValue

Declaration

property BlackValue: double;

Description

Specifies (along with WhiteValue) the value range from black to white.

For example, if your image is a gray scale (256 levels) where only values from 100 to 200 are used (100 is black and 200 is white), to display the image you must write:

ImageEnView1.IEBitmap.BlackValue := 100;
ImageEnView1.IEBitmap.WhiteValue := 200;
ImageEnView1.Update();

Valid ranges will depend on the format, e.g.
ie8g, ie24RGB: 0 - 255
ie16g, ie48RGB: 0 - 65535
ie32f: 0.0 - 1.0

Note:
◼The following pixel formats are supported: ie8g, ie16g, ie24RGB, ie48RGB, ie32f
◼To automatically set the BlackValue and WhiteValue to the lowest and highest values in the image, call AutoCalcBWValues
◼To permanently apply the range to the image, use StretchValues
◼When setting BlackValue, ensure you also set WhiteValue which has a default value of 0
◼Set both BlackValue and WhiteValue to 0 to disable stretching

Default: 0

Demos

	Demos\Display\DisplayAdjust\Display.dpr
	Demos\InputOutput\DicomRange\Dicom.dpr

Examples

// Calculate Window Center and Width
WindowWidth := Round( ImageEnView1.IEBitmap.WhiteValue - ImageEnView1.IEBitmap.BlackValue + 1 );
WindowCenter := Round( ImageEnView1.IEBitmap.BlackValue + 0.5 + ( ImageEnView1.IEBitmap.WhiteValue - ImageEnView1.IEBitmap.BlackValue ) / 2 );
Caption := 'WindowWidth: ' + IntToStr( WindowWidth ) + ' - WindowCenter: ' + IntToStr( WindowCenter );

// Set black and white values based on Window Center and Width
ImageEnView1.IEBitmap.BlackValue := WindowCenter - 0.5 - ( WindowWidth - 1) / 2;
ImageEnView1.IEBitmap.WhiteValue := WindowCenter - 0.5 + ( WindowWidth - 1) / 2;

TIEBitmap.BlackValue