The invention discloses an encrypted 3D
mesh model reversible
information hiding method based on a depth-first
spanning tree, which comprises the following steps: firstly converting vertex coordinates of a 3D
mesh model into non-negative integers, then constructing the depth-first
spanning tree according to a triangular surface relationship, then comparing all non-root nodes of the depth-first
spanning tree with father nodes of the depth-first spanning tree, performing Multi-MSB replacement, and finally, constructing the depth-first spanning tree according to the non-negative integers. The method comprises the following steps of: obtaining Multi-MSB replacement length frequency number statistics and a vertex structure array after Multi-MSB replacement, recoding the same bit number to obtain a
Huffman coding structure array, carrying out bit
stream integration, and carrying out
encryption by using a model
encryption key; secondly, embedding the number of embeddable bits into the end of the encrypted information
stream, and
shuffling to reform an encrypted 3D
mesh model; the information hider embeds the information to generate a secret-carrying 3D mesh model, and the
authorization receiver decides whether to restore the model or extract the information or to simultaneously restore the model and extract the information according to different secret keys. According to the method, the problem that the number of embeddable vertexes is small is solved through the implementation of the depth spanning tree, the length of auxiliary information can be shortened, and the
embedding rate is greatly increased.