本文探讨了“签名的签名”技术。针对签名图像的特点,对二值图像水印嵌入方法和灰度图像水印嵌入方法进行了研究,建立了二值图像的像素可翻转值查找表,给出了签名图像的4级灰度表示法。实验结果表明,本文给出的基于4级灰度的LSB水印嵌入方法具有嵌入容量大,不可见性好,简单易行等特点。 This article explores the “signed signature” technique. According to the characteristics of the signature image, the binary image watermark embedding method and the gray image watermark embedding method are studied. The pixel rollover value look-up table of the binary image is established, and the 4-level gray representation of the signature image is given. Experimental results show that the LSB watermark embedding method based on 4-level grayscale presented in this paper has the characteristics of large embedding capacity, good invisibility, simple and easy to implement.