# A Robust and Secure Watermarking Approach Based on Hermite Transform and SVD-DCT
## 2 Related Work
The methods studied were classified into multiple categorizations of watermarking: perceptibility (visible and invisible watermark), accessibility (private and public), document type (text, audio, image, video), application (copyright protection, image authentication, fingerprinting, copy and device control, fraud and temper detection), domain-based (spatial domain, transform/frequency domain), type of schema (blind and non-blind), and cover image. The techniques analyzed were tested against several attacks: image-processing, geometric, cryptographic, and protocol attacks, using the more-representative evaluation measures, for example the PSNR, NCC, BER, and SSIM. [PERSON] and [PERSON] [9] proposed a DWT-, DCT-, and SVD-based watermarking method to address common watermarking and rotation attacks. The scrambled watermark was inserted into the LL sub-band. In addition, the authors signed the \(U\) and \(V\) matrices to avoid the false positive problem. In [10], [PERSON] et al. reported a hybrid watermarking method of grayscale images based on DWT, DCT, and SVD for later embedding the watermark into the LH and HL sub-bands. Multi-dimensional PSO and an intertwining logistic map were used as the optimization algorithms and encryption models for watermarking robustness enhancement. [PERSON] et al. [11] evaluated two watermarking methods, a DWT based and an approach using the Lifting Wavelet Transform (LWT) under the same watermark and embedding it into the middle-frequency band. The results showed that, in terms of objective image quality, the LWT method outperformed the DWT method, whereas the DWT watermarking technique exhibited superior resilience against various attacks compared to the LWT approach. [PERSON] and [PERSON] [12] proposed a watermarking technique using human speech signals as the watermark. For this, the watermark's hybrid coefficients were derived using the DCT and subsequently subjected to SVD. Then, these coefficients were inserted into the coefficients of the host image, which were generated by a DWT followed by a Fast Discrete Curvelet Transform (FDCuT). In [13], [PERSON] et al. presented a DWT-, DCT-, and SVD-based watermarking method. In addition, security was accomplished through a Set Partitioning in a Hierarchical Tree (SPIHT) and by the AT. [PERSON] et al. [14] proposed a zero-watermarking approach applied to color images using the DWT, DCT, and SVD, taking advantage of the multi-level decomposition of the DWT, the concentration of the energy of the DCT, and the robustness of the SVD. Due to three color channels being used to embed the watermark, it was extracted by a voting strategy. In [15], [PERSON] and [PERSON] presented a composed watermarking proposal that involved DWT ad DCT analysis and an SVD approach to insert binary watermarks. The approach was image-adaptive, which identified blocks with high entropy to determine where the watermark should be embedded. [PERSON] et al. [16] reported a watermarking hybrid approach for digital images using LWT and DCT analysis and an SVD technique. Their proposal applied the Canny filter to identify regions with a higher number of edges, which were used to create two sub-images. These sub-images served as the reference points for both the embedding and extracting stages. Moreover, during the marking stage, the method used Multiple Scaling Factors (MSFs) to adjust various ranges of the singular-value coefficients. [PERSON] et al. [17] reported a watermarking schema in digital images through a composed method applying DCT and DWT analysis and an SVD approach. In addition, the method used a logistic chaotic map. [PERSON] [18] proposed a scheme that protected the information with an adjustable balance between image quality and watermark resilience against image-processing and geometric attacks. The method was based on the DWT, DCT, and SVD techniques and provided an adaptive PSNR for the imperceptibility of the watermarks. [PERSON] et al. [19] investigated different digital watermarking schemes, comparing the protection and sensible limit.