Fills the 1 pixel size holes in the vertical direction on a GdPicture image or into an area of a GdPicture image defined by SetROI() function. 

This function should be use only on bitonal images.

public GdPictureStatus FxBitonalFillHolesV(
    int ImageID
);

Public Function FxBitonalFillHolesV(
    ByVal ImageID As Integer
) As GdPictureStatus

A member of the GdPictureStatus enumeration.