Table 4 Peak signal-to-noise ratio (PSNR) values (in dB) of the distorted watermarked Lena image when subjected to various attacks.
From: Time-Frequency and Time-Scale-Based Fragile Watermarking Methods for Image Authentication
Attacks | Example: Lena image |
|---|---|
JPEG comp. 90% | 38.83 |
JPEG comp. 80% | 35.94 |
JPEG comp. 70% | 34.41 |
JPEG comp. 60% | 33.34 |
JPEG comp. 50% | 32.56 |
JPEG comp. 40% | 31.82 |
Histogram equalization | 16.69 |
Sharpening | 29.31 |
Blurring | 31.53 |
Gaussian noise | 32.77 |
Salt-and-pepper noise | 24.85 |