CImage:SubDarkFrame

CImage:SubDarkFrame

The SubDarkFrame method corrects the thermal image signature by subtracting a dark frame from the current image. The result replaces the current image.

Syntax

bResult = CImage:SubDarkFrame( Dark, datatype=nil )

Dark is the CImage containing the thermal dark frame.
The optional datatype specifies the output data type as a number or string.
On success, this method returns true.
On failure, false. is returned.

Remarks

This method applies a dark frame correction to the image and updates the image header with the appropriate history and other keywords. The data type of the image may be changed as part of the correction, for example, to increase the precision of the dark correction. Mira automatically handles mixing different data types between the source image and the dark frame.

Example

The following script fragment loads an image and subtracts a dark frame. The output data type is changed to "float" to maintain precision of the correction process. In practice you might maintain the dark frame in memory across a loop to process many images:

I = CImage:new()	-- create a new CImage
I:Open( sPath )	-- load the image from file sPath
Dark = CImage:new()	-- create a new CImage
Dark:Open( sDarkName )	-- load the dark frame from sDarkName
I:SubDarkFrame(Dark,"float")	-- remove the dark frame from image I
I:Save()	-- save the image
I:delete()	-- delete the image from memory
Dark:delete()	-- delete the thermal frame from memory