In this paper, we extend Isotropy-based LSB steganalysis for detecting the existence of hidden message and estimating
hidden message length when the embedding is performed using both of two distinct embedding paradigms in one or
more than one LSB. The extended method is based on the analysis of image isotropy, which is usually affected by secret
message embedding. The proposed method is general framework because it encompasses a more general case of LSB
steganalysis, namely when the embedding is performed in more LSBs and using both embedding paradigms. Compared
with our previous proposed weighted stego-image based method, the detection accuracy is high. Experimental results
and theoretical verification show that this framework is an effective framework of LSB steganalysis.