Secured telemedicine of medical imaging based on dual robust watermarking

Additional Information Delivery to Image Content via Improved Unseen–Visible Watermarking

“…Considering Table 4 and several aspects of each algorithm shown in Table 5, the proposal is more suitable to be used in practical applications of additional information delivery, information security tasks [15][16][17][18][19] and other related fields [20], such as is mentioned in Section 1.…”

“…To exhibit the watermark, the processing capabilities equipped into capture and display devices are used. The UVW algorithms [6][7][8] embed a binary watermark by a slight adjustment of the embedding region pixels and guarantee a watermark imperceptibility above 40 dB; however, they do not offer better performance in images without a darkness plain region [15,16]. To exhibit the watermark, these algorithms take advantage of the image enhancement function equipped into the display devices such as GCF [13], brightness [30], contrast [14] and the angle of vision [21,22], such that a complex algorithm is not required.…”

“…Finally, based on the previous evaluation, the binary watermark must be embedded into R according to its mean value µR; in this context, the watermark's '0s' are embedded into the pixels of the embedding region in the range of (0, µR-1), f:W = 0→(0, µR-1), and the '1s' in the range of (µR, 255), f:W = 1→(µR, 255), where f corresponds to the general embedding strategy. According to the proposed strategy, an embedding error (EE) measurement is obtained; it considers all the pixels in the ranges (0, µR-1) and (µR, 255) where the '0s' and '1s' of the watermark were embedded, respectively, as given by (15). With the aim to reduce the drawbacks of Figure 5a,b, the proposed watermark complement strategy is based on the evaluation of the pixels within the embedding region with respect to its mean value.…”

“…Step 3: The watermark is evaluated by (13) to select the suitable watermark W , ensuring the minimum embedding error given by (15).…”

“…In this proposal, additional information delivery to the image content refers to the application of the general scenario of the UVW algorithms in daily life; when the endusers exhibit the QR watermark, the decoded information could be a company website, information of singers, dress designer, location or another kind of information that has or does not have relation to the image content. Additionally, it is not limited to extend the applicability to information security tasks such as medical imaging [15,16], deepfake prevention [17], 3D-video protection [18], face recognition authentication [19] and other related fields [20]. However, to obtain better results in all those applications, several drawbacks of the UVW algorithms must be improved: first, the algorithms only require large image regions with low intensity [6][7][8]14] second, embedding strategies increase histogram distortion and visual degradation of the watermarked image, impacting the legibility of the visual content and the watermark imperceptibility.…”