Declaration: TMetaData.PixMask[PosX, PosY: integer]: integer;
The array property PixMask provides access to the pixel masks of individual pixels. The parameters PosX and PosY specify the indices of the corresponding pixel (valid ranges: 1...SizeX, and 1...SizeY, respectively).

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