Reversible Data Hiding Based on Improved Block Selection Strategy and Pixel Value Ordering

Weighted Average-Based Complexity Calculation in Block Selection Oriented Reversible Data Hiding

“…en the second largest and second smallest pixels are selected in calculation. In addition, Tang et al [23] introduced an average strategy, which evaluates the difference of both the largest and smallest pixels by employing the difference between the average value of their valid neighbors. As a result, a single complexity value is not utilized for both sides anymore.…”

“…We select three images Boat, Man, and Airport from the USC-SIPI image data set [33]; three high definition images Vanessa, Philipp, and Mohammad from the UNSPLASH image data set [34]; and three medical images 8FDE, Aweek, and RXtorace from the real world ChestX-ray14 image data set [35] separately as test images to perform our experiments, each of which is shown in Figures 3(a)-3(h), and 3(i), respectively. Our scheme is compared with PVO scheme [12], Pan et al's scheme [22], and Tang et al's two schemes [23] in performance. All results are on average of 20 tries.…”

“…For instance, under the embedding capacity of 2,705, 8,115, 13,526, 18,936, 24,346, 29,757, 32,462, 37,872, 43,283, and Table 1: e maximum capacities (MC) of nine test images from USC-SIPI data set [33], UNSPLASH data set [34], and ChestX-ray14 data set [35]. The proposed scheme PVO scheme [12] Pan et al 's scheme [22] Tang et al 's average based strategy [23] Tang et al 's median based strategy [23] (h) As a comparison, our proposed weighted average-based complexity calculation scheme not only ensures enough number of context pixels to participate in complexity calculation but also eliminates those invalid ones to improve performance. Furthermore, we assign different weights to each one of the valid context pixels to distinguish its contribution to the final complexity value.…”

“…Steganalysis focuses on detecting whether a certain cover image has already been embedded, which is able to be utilized to evaluate the security of the proposed scheme. The proposed scheme PVO scheme [12] Pan et al 's scheme [22] Tang et al 's average based strategy [23] Tang et al 's median based strategy [23] (i) According to whether it is focused on a particular embedding algorithm, steganalysis can be classified into universal steganalysis and the targeted one. In particular, we employ NCC and BER to achieve universal detection and RS analysis to achieve targeted detection.…”

“…Nevertheless, the actual performance is seriously restrained by the smoothness of selected blocks, which is defined to be their complexity value. Even though a lot of works [20][21][22][23][24] focus on this problem, the actually obtained result is not always accurate in reflecting the real smoothness. e main reason is that those invalid context pixels are still assigned too large a weight to participate in the calculation, which inevitably introduces a lot of uncertainty.…”