# Invisible Shield: Unveiling an Efficient Watermarking Solution for Medical Imaging Security
## 4 Results
### Simulation  
Python version 3.8 was employed to create the algorithms, and OpenCV served a pivotal role in image processing operations, such as reading and converting images to grayscale, and was crucial for feature detection and visualization in the realm of medical imaging. Numpy complemented these tasks by providing robust support for numerical and matrix operations, essential for the sophisticated data handling required in encryption algorithms. Together, these libraries formed the backbone of the script, enabling complex image manipulation and encryption processes critical for securing patient information in medical imaging. The proposed methodology involves the evaluation of a medical image sized at 1024 \(\times\) 1024 pixels as the host image, on which the FDCuT is executed to extract its curvelet coefficients. Specifically, the high-frequency curvelet coefficients, sized at 1024 \(\times\) 1024, are selected to embed a watermark image. These high-frequency curvelet coefficients are transformed into 16,384 separate and non-overlapping blocks, each sized at 8 \(\times\) 8. The Discrete Cosine Transform (DCT) coefficients for each block are then derived by applying block-wise DCT. Figure 2 presents a comparative analysis of original and watermarked images and their respective histograms. A compelling advantage of our algorithm becomes evident when observing the histograms of these images. The generated histograms reveal a remarkably subtle difference, suggesting that the watermarking process minimally impacts the image's overall distribution of pixel intensities. This slight dissimilarity implies that visually distinguishing between the original and watermarked images would be challenging for the human eye. This inconspicuous alteration underscores the strength of our approach, ensuring that the embedded watermark has negligible visual impact on the image's quality or appearance. By maintaining the integrity and aesthetic quality of the image, our algorithm offers a robust and inconspicuous method of safeguarding against unauthorized use or tampering. Figure 3 showcases a compelling demonstration of our proposed algorithm's advantage through a side-by-side comparison of original and watermarked images. The 'Pixel Intensity Difference' section shows the subtle yet significant difference. This visual representation highlights the altered pixel intensities resulting from the watermark embedding process, revealing the regions where changes have occurred. Despite the slight variations,the images maintain a strikingly similar appearance, affirming our algorithm's effectiveness in preserving the original image's visual integrity. The pixel intensity differences portrayed in the 'Pixel Intensity Difference' panel, although existent, reinforce the robust nature of our algorithm. The essential advantage is the ability to embed a watermark into the image without drastically modifying the visual aspects. It ensures that while alterations are present, they need to be more inconspicuous, making it challenging for the human eye to discern any notable changes between the original and watermarked images. This subtle difference speaks to the algorithm's ability to protect the image's integrity while maintaining its overall visual appeal. Figure 4 displays the outcome of applying RSA encryption to the watermarked image generated from the original image. The resulting image, termed the 'Generated Encrypted Image', is the product of our algorithm's encryption process. Applying the robust RSA (Rivest-Shamir-Adleman) encryption technique, the watermarked image, containing the embedded watermark and subtle modifications, is further fortified and transformed into  
Figure 3: Pixel intensity difference. Figure 2: Compare the original and watermarked image. an encrypted form. This transformation ensures the secure concealment and protection of the embedded information within the image. The 'Generated Encrypted Image' serves as a testament to the comprehensive security measures implemented by our proposed algorithm.