Affiliations: Institute of Computer Science and Engineering National
Chung Hsing University 250, Kuo Kuang Road,402 Taichung, Taiwan.
E-mail: cmwang@dragon.nchu.edu.tw
Abstract: We present an effective message embedding scheme for 3D models. We
propose the unit length as the quantizer to generate an embedding order list
and an embedding index list. Our scheme considers every two elements in the
embedding order list as the order pair, and we embed 3 bits of 0 or 1 secret
message into the index pair associated with the order pair. The message
embedding is effective requiring, at most, adding 1 to, or subtracting 1 from,
the index pair. This reflects a slight perturbation of a points coordinates
where the magnitude of the perturbation is no greater than one unit length. Our
algorithm achieves a high embedding capacity, being 4.5 times the number of
points in the point cloud models. This amount of capacity allows us to convey a
502x502 resolution of the black-and-white image into a point cloud model
consisting of 56,194 points for covert communication. The capacity magnitude is
50%-75% higher than that of the current state-ofthe- art algorithms, yet the
model distortion due to the message embedding is smaller than that of our
counterparts. Our algorithm is robust against translation, rotation, and
uniformly scaling operations. It is fast, simple to implement, and the message
can be extracted without referring to the original point cloud model. We
believe our scheme is appropriate for most point cloud models.
Keywords: Message embedding, 3D models, quantization, information hiding, steganography
