CT image authentication for telemedicine applications using self-embedding pixel-wise technique with chaotic coordinate mapping and lfsr

In healthcare, CT (computed tomography) is an essential diagnostic modality. Telemedicine can help with the safe and centralized transmission, storage, and retrieval of CT images. Image authentication is required during the network transmission of the images. Fragile watermarking is an essential tool for ensuring authentication; it can spot even subtle changes to an image. In this paper, we have proposed a pixel-based blind self-embedding fragile watermarking technique for e-healthcare applications. Authentication bits are generated through Chaotic Coordinate Mapping, which involves a series of logical and cyclic operations within the spatial features of the image. The Linear Feedback Shift Register (LFSR) is employed to generate both a random matrix and a cryptic key. Ensuring perceptual quality after the watermark insertion is necessary for CT images, specifically for low-dose images. The proposed method has been tested on both low-dose and full-dose CT images, demonstrating a high perceptible quality. For low-dose images, we achieved an average PSNR of approximately 48 dB; for high-dose images, the value is approximately 54 dB; the average SSIM value for both low-dose and high-dose images is 0.97, and the tamper detection rate for low-dose and high-dose images is nearly equal to 0.99. Notably, the proposed approach does not produce any false positive rate (FPR), making it suitable for both low and high-dose CT images. Subjective and objective evaluation metrics are tested to check the suggested approach’s effectiveness.