Blt Method

In This Topic

Description

Copy pixel data from one image to another

Syntax

Visual Basic
Public Sub Blt( _ ByVal Source As DicomImage, _ ByVal SourceX As Long, _ ByVal SourceY As Long, _ ByVal DestinationX As Long, _ ByVal DestinationY As Long, _ ByVal SizeX As Long, _ ByVal SizeY As Long, _ ByVal SourceFrame As Long, _ ByVal DestinationFrame As Long, _ ByVal Zoom As Single, _ ByVal Window As Boolean _ )

Visual Basic

Public Sub Blt( _
   ByVal Source As DicomImage, _
   ByVal SourceX As Long, _
   ByVal SourceY As Long, _
   ByVal DestinationX As Long, _
   ByVal DestinationY As Long, _
   ByVal SizeX As Long, _
   ByVal SizeY As Long, _
   ByVal SourceFrame As Long, _
   ByVal DestinationFrame As Long, _
   ByVal Zoom As Single, _
   ByVal Window As Boolean _
)

Parameters

Source: The image to copy from
SourceX: The X coordinate of the left edge of the area to copy from
SourceY: The Y coordinate of the top edge of the area to copy from
DestinationX: The X coordinate of the left edge of the area to copy into
DestinationY: The Y coordinate of the top edge of the area to copy into
SizeX: The width of the source area to copy
SizeY: The height of the source area to copy
SourceFrame: The frame to copy from (1-based)
DestinationFrame: The frame to copy to (1-based)
Zoom: The magnification factor to apply
Window: Whether to apply standard windowing to the image data during the transfer

Remarks

This method takes frame SourceFrame of Source, and magnifies by the factor Zoom. It extracts from that a rectangle with a top left corner at Source/Y and size SizeX/Y. It then overwrites this onto an area of DestinationFrame of the destination image (the image on which this method is called), putting the top left corner of the rectangle at DestinationX/Y.

If Window is true, the data is windowed before transfer, and scaled to match the full bit depth of the destination. If window is false, then data is copied "as is", but in this case, the photometric interpretation of the two images must be the same (RGB, MONOCHROME2 etc.) Note that Zoom is applied BEFORE selecting the rectangle.

Because this image over-writes existing pixels, it is necessary that the destination image must have allocated and writeable pixels. When making a montage from scratch, this is commonly done either by using AllocatePixelSpace, or when starting with an “base” image, PrinterImage is useful, as it produces images scaled to the full bit depth. Where the destination image has been read from disk, it may be necessary to call the DecompressAll method to ensure that a writeable copy of the pixel data is made, rather than the read-only copy mapped from the disk.

Any type of image may be used for the source, but when windowing, the destination image must have unsigned pixel values.