Comment on "Optical image encryption with Hartley transforms".
We numerically demonstrate that the image encryption algorithm with intensity random filtering in the Hartley domain proposed in a recent Letter by Chen and Zhao [Opt. Lett.31, 3438 (2006)] has the problem of low security. Original image information can be visually revealed only by an inverse Hartley transform without any decryption key.
Liu
Zhengjun
Z
Harbin Institute of Technology, Department of Physics, Harbin, China.
Liu
Shutian
S