Cryptanalysis and Improvement of an Efficient and Secure Medical Image Protection Scheme

Figure 7

Correlation plots of two adjacent plain image pixels in (a) horizontal, (b) vertical, and (c) diagonal directions; correlation plots of two adjacent pixels of the cipher image in (d) horizontal, (e) vertical, and (f) diagonal directions.

(a)

(b)

(c)

(d)

(e)

(f)