An Intragroup and Intergroup Multiple Secret Images’ Sharing Scheme with Each Participant Holding One Shadow Image

Table 1

Meanings of the symbols.

Symbol	Meaning
	Group 1, Group 2
	The participant
	The order number of
	The shadow image held by
	The intragroup secret image of
	The intergroup secret image of Group 1 and Group 2
	The recovered intragroup secret image of
	The recovered intergroup secret image of Group 1 and Group 2
	The threshold of intragroup SIS of
	The threshold of intergroup SIS of Group 1 and Group 2
	A pixel value of
	A pixel value of
	A pixel value of