Cryptography Reference
In-Depth Information
Fig. 5.11.
The embedding results (stego-images) of the proposed method.
one secret bit can then be embedded in one pixel. These results can be seen
from our experimental results.
Some fluctuations are shown in Fig. 5.12. This phenomena is produced by
the clustering result and the conditions of embeddability. The threshold values
T
α
, T
β
,andT
γ
affect the embedding capacity and the image quality. Changes
of the threshold value T
γ
lead to changes of the clustering result. When the
threshold value T
γ
is larger, most color occurrence frequencies are more likely
to gather around the same cluster. The embedding capacity will therefore
increase. When the threshold value T
γ
is larger, the difference between clusters
becomes larger. Some of the image data will become non-embeddable, which
may lead to a drop of the embedding capacity.
To sum up, we have proposed an embedding scheme for palette images
that can offer a higher embedding capacity with better image quality than the
currently existing methods. We adopt the concept of clustering to obtain high
capacity, and include the concept of embeddability in order to maintain the
image quality. The two-round embedding procedure is used to embed adequate
