Expansion high payload imperceptible steganography using parameterized multilayer EMD with clock-adjustment model

Steganography is a widely used technique for protecting data privacy. In such research, the desired attributes always include undetectability, a high embedding payload, and excellent image quality for the stego-image. However, achieving both high image quality and substantial embedding payloads often involves a trade-off. The development of an algorithm that can achieve this balance remains a key focus of these studies. Although progress has been made, there is still room for improvement in optimizing this balance between embedding capacity and image quality in current research. To address this challenge, in this study, we propose a novel steganographic method called the parameterized multilayer EMD with clock adjustment model (PMEMD–CAM). In the proposed method, we generalize the embedding and extraction process, offering a more efficient and flexible way to conceal data via the innovative concept of a CAM. In CAM, the sender can predefine the parameters to determine the number of pointers on a clock and the weight of each pointer. The pixel values in a block subsequently result in an initial clock status, and the corresponding secret data yield a target clock status. The main idea of CAM is to adjust the pointers in the clock with a minimum number of cost steps to achieve the target status for hiding the secret data. Subsequently, the authorized receiver can extract the secret data based on the clock model. In addition, a multilayer embedding strategy is applied to improve the embedding payload. Experimental results demonstrate that the proposed method achieves a high capacity of 4.754 bits per pixel (bpp) with a peak signal-to-noise ratio (exceeding 30 decibels (dB), outperforming existing schemes. Furthermore, our method exhibits resilience against various steganalysis attacks.