Image Encryption Algorithm Based on Adaptive Wavelet Chaos

Table 2

Comparison of PSNR of images after decryption by four encryption algorithms.

Method type	Lena	Couple	Gray
[26]	19.32	20.09	19.56
[27]	19.71	20.49	19.95
[28]	20.37	20.18	21.06
Ours	21.08	20.94	21.18