PixMaskExtents

Declaration:	TMetaData. PixMaskExtents (ixMask: integer; var Extents: TRect): integer;
Retrieves the circumscribing rectangle of the mask specified by the parameter ixMask. The circumscribing rectangle is returned in the parameter Extents. The function returns the following error codes:  0 .... everything OK -1 ... specified mask does not exist

Hint:

In order to directly access the metadata of the currently loaded dataset you can use the pre-declared global variable MData.