The Proposed Hierarchical (k, k) VSS Scheme (The analysis of "contrast" and "security" conditions for two-layer (4, 4) scheme)

S 11+ S12 or

S 21+ S 22

S 11 + S 21 or S 11+ S 12 or

S 12 + S 21 or S 12+ S

1. all 4 sub pixels are black

(P.=0. 5)

2. three black and one white

sub pixels (P.=0.5)

1. all 4 sub pixels are

black (P.=0. 5)

2. three black and one

white sub pixels(P.=0.5)

1. all 4 sub pixels are black

(P.=0.25)

2. two black and two white

sub pixels (P.=0.25)

3. three black and one white

sub pixels (P.=0.5)

1. all 4 sub pixels are black

(P.=0. 5)

2. three black and one white

sub pixels (P.=0.5)

all 4 sub pixels are black

(P.=1.0)

three black and one white sub pixels (P.=1.0)

two out of four three out of four four out of four

S 11 + S 12 + S 21 + S 22

Original

Pixel

1. all 4 sub pixels are black

(P.=0.25)

2. two black and two white

sub pixels (P.=0.25)

3. three black and one white

sub pixels (P.=0.5)

one out of four

two black and two white sub pixels (P.=1.0)

The analysis of "contrast" and "security" conditions for two-layer (4, 4) scheme

Our hierarchical VSS scheme is a probabilistic scheme. The original white pixel in the stacked picture(S 11 + S 12 + S 21 + S 22) may include four all black sub pixels with probability 50%. This is minor due to the probability. For example, two adjacent white original pixels will have all black sub pixel with probability 1/4, three adjacent white original pixels will have all black sub pixel with probability 1/8, ¡K, and so on.

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