A COMPUTER ENGINEERING APPROACH TO DIGITAL IMAGE COPYRIGHT PROTECTION USING BLOCK-BASED LSB WATERMARKING

Abstract

Digital image watermarking has emerged as an effective technique for protecting multimedia content against unauthorized copying and copyright infringement. In this paper, an improved spatial-domain watermarking method based on block segmentation and Least Significant Bit (LSB) embedding is proposed. The host image is divided into non-overlapping 8×8 blocks, and watermark information is embedded into selected pixels to achieve high imperceptibility while preserving image quality. The proposed framework distributes the watermark over localized regions, thereby improving data concealment and reducing the structural vulnerability associated with conventional LSB methods. Experimental evaluation was performed using standard benchmark images, and the quality of the watermarked image was assessed using the Peak Signal-to-Noise Ratio (PSNR), while extraction accuracy was measured using the Normalized Correlation (NC). The results demonstrated an average PSNR of 51.14 dB and an NC value of 1.00, indicating excellent visual quality and accurate watermark recovery. In addition, the algorithm exhibited low computational complexity with an execution time of less than 0.12 s. These findings demonstrate that the proposed method provides an effective balance between imperceptibility, extraction accuracy, and computational efficiency, making it suitable for real-time digital copyright protection applications.