A Robust Coverless Image Steganography Algorithm Based on Image Retrieval with SURF Features

Table 1

Comparison of the two types of coverless image steganography algorithms.

Algorithm	Is there a one-to-one correspondence between images and hash values?	Rely on generating a hash sequence based on the image?	Necessary to manually establish a mapping rule?	Need a large image database?
Generative-based coverless image steganography	Yes	Yes	No	Yes
Mapping-based coverless image steganography	Yes	No	Yes	No