# Feature-Based Image Watermarking Algorithm Using SVD and APBT for Copyright Protection
## 1 Introduction
[15] proposed a fragile watermarking for image authentication in the wavelet domain, where the authentication code is embedded into the two-level low frequency sub-band. In [16], [PERSON] and [PERSON] introduced a fragile watermarking tampering detection with compressed images based on a fuzzy transform, which is applied to compress each block. Besides, fuzzy c-means clustering technique is proposed to form the relationship between image blocks, and this method achieves more accurate tampering detection and localization. [PERSON] and [PERSON] [17] presented a passive approach for tampering detection and location in video sequences with camera motion, which is based on spatio-temporal coherence analysis. The scale-invariant feature transform (SIFT) [18] is a classical algorithm for interest points detection, as well as local features description, which has three advantages: (1) the number of extracted feature points or keypoints is significant with appropriate parameter settings; (2) the image feature extracted by SIFT has great uniqueness for accurate matching; and (3) SIFT features have better invariance ability on rotation, scaling, and translation. Owing to its efficiency [19], SIFT algorithm is widely used in the field of image processing to match two images, locate the position, and recognize objects. Moreover, SIFT provides good performance of watermarking schemes in recent years. [PERSON] et al. [20] firstly proposed a novel image watermarking scheme using local invariant features, and embedded the watermark into circular patches generated by SIFT. In [21], [PERSON] et al. proposed an image watermarking scheme based on SIFT and DWT, and applied the DWT on the selected SIFT areas. [PERSON] and [PERSON] [22] proposed an anti-geometric attack watermarking scheme based on integer wavelet transform (IWT) and SIFT, where feature points in red components of the image are extracted by SIFT, and blue and green components are performed by IWT to extract low frequency coefficients for watermark embedding. [PERSON] et al. [23] presented an adaptive robust watermarking scheme based on discrete Fourier transform (DFT) and SIFT to deal with the synchronization errors. [PERSON] et al. [24] proposed a robust SIFT and DCT-based watermarking scheme, embedding the watermark into the selected feature regions after DCT. In [25], [PERSON] and [PERSON] introduced an SVD and SIFT-based watermarking algorithm to solve the synchronization problem, where SIFT is used for watermarking resynchronization. Owing to the robustness feature of SIFT and SVD, as well as better concentration of all phase biorthogonal transform (APBT) in low frequencies, we propose the idea of combining local digital watermarking with SIFT, SVD, and APBT, and make comparisons between previous watermarkingschemes and the proposed watermarking algorithm in this paper. The purpose of this paper is to propose a robust watermarking algorithm with better imperceptibility and stronger robustness for copyright protection. The remainder of this paper is organized as follows. Section 2 introduces the related work. Section 3 describes the proposed algorithm in detail. Experimental results and analyses are presented in Section 4. Conclusions and future works are given finally in Section 5.