Schematic procedure of rotational mathematical morphology. (a) Original image. (b) Straight line-segment SE B. (c) Setting of the rotation angles. (d) Process of RMP opening. Original image is rotated and each rotated image is processed by opening with the straight line-segment SE B. Orange arrows in each rotated image denote the scan lines by this SE. This rotational processing permits the isotropic processing with a single straight line-segment SE. All processed images (h
) are unified as a result of the RMP opening.