The source luminance range for pixel value casts during CreateRegionAccess

A Variant value.  

object.CastingSourceRange [= value]

The CastingSourceRange Property syntax has these parts:

Added after IQBase Version 1 shipped

By default the source luminance range for casting luminances during a CreateRegionAccess (or McFeatures.AccessMaskedImageData) call is RangeMin to RangeMax. However there are some circumstances where you would like to have a different source luminance range to map some luminance range of source pixels onto a larger or smaller range for further computation.

CastingSourceRange is always reset to its default value (RangeMin to RangeMax) after any call to CreateRegionAccess or to McFeatures.AccessMaskedImageData. Note that many methods that operate on image data may indirectly call one of these methods, so you need to make an assignment to CastingSourceRange only just before calling CreateRegionAccess.

You do not need to change CastingSourceRange just to convert the luminance range of one image AOI to another range in another image, because the ConvertEx method takes source and destination luminance range arguments that will do the job for you. However, if you need to do a more complex image copy that also involves an unusual luminance range cast, then setting the CastingSourceRange before calling CopyToNewImage might be necessary.