Watermarking of digital images using wavelet and discrete cosine transforms
    1.
    发明授权
    Watermarking of digital images using wavelet and discrete cosine transforms 有权
    使用小波和离散余弦变换对数字图像进行水印

    公开(公告)号:US06975733B1

    公开(公告)日:2005-12-13

    申请号:US09786823

    申请日:1999-09-10

    IPC分类号: G06K9/00

    摘要: The present invention relates to a method for embedding a watermark into a black and white or color digital image [D(x)]. Basically the inventive method comprises the steps of transforming the digital image using a wavelet transform [WC(y)], transforming a watermark using discrete cosine transform (DCT), integrating the wavelet-transformed digital image with the DCT-transformed watermark [DW(x)+WC(y)] to insert the watermark into the image, and generating the watermarked image using inverse wavelet transform [D(x)′]. For color images, RGB mode is converted into YIQ mode using a conversion matrix and the wavelet transform is applied to the Y-, I-, Q-values. This inventive digital watermarking of a color image is found to be highly robust against lossy compression and other image processing operations, compared to conventionally known methods which are known to be unsuitable for watermarking color images.

    摘要翻译: 本发明涉及一种将水印嵌入到黑白或彩色数字图像[D(x)]中的方法。 基本上,本发明的方法包括以下步骤:使用小波变换[WC(y)]变换数字图像,使用离散余弦变换(DCT)变换水印,将小波变换数字图像与DCT变换水印[DW x)+ WC(y)]将水印插入到图像中,并使用逆小波变换[D(x)']生成带水印的图像。 对于彩色图像,使用转换矩阵将RGB模式转换为YIQ模式,并将小波变换应用于Y,I,Q值。 发现彩色图像的本发明的数字水印技术对于有损压缩和其他图像处理操作来说是高度鲁棒的,与已知的不适合于对彩色图像进行水印化的已知方法相比。