Fast and Robust Watermarking Method Based on DCT Specific Location

In many studies related to watermarking, spatial-domain methods have a relatively low information-hiding capacity and limited robustness, and transform-domain methods are not applicable in real-time processes because of their considerably high computational time. In this paper, we propose a novel watermarking method based on a discrete cosine transform (DCT), which guarantees robustness and low computational complexity. First, we calculated the DCT coefficient of a specific location. Then, a variation value was calculated according to the embedding bits and quantization steps to modify the coefficient. Last, we embedded watermark bits by directly modifying the pixel values without full-frame DCT. Tests comparing invisibility, robustness, and computational time were conducted for determining the feasibility of the proposed method. The results showed that the proposed method had the faster and the more robust performance than previous studies.