11. A method for extracting a digital watermark ŵ from textual and/or vector graphics documents of electronic and/or hard-copy form based on the modulation of luminance or grayscale values, of color values, or of halftone patterns of characters or of vector elements, wherein the watermarked and potentially distorted or attacked document {hacek over (y)}′ is segmented, processed and the watermark extracted as ŵ, the codeword ĉ estimated, and the message {circumflex over (m)} decoded, the method comprising the steps of (a) applying document segmentation to the watermarked document {hacek over (y)}′, including the selection of documents text and/or vector graphics components y text , (b) extracting the potentially modulated elements from the text and/or vector graphics components, including performing character and/or elements segmentation for text and/or vector graphics documents, (c) estimating the watermark signal ŵ from the modulated grayscale, color and/or halftone pattern attributes, (d) generating a pilot signal; estimating and compensating the extracted watermark ŵ state and desynchronization, based on the pilot signal, resulting into the estimated codeword ĉ; decoding the codeword ĉ resulting into the final message {circumflex over (m)}.
11. A method for extracting a digital watermark ŵ from textual and/or vector graphics documents of electronic and/or hard-copy form based on the modulation of luminance or grayscale values, of color values, or of halftone patterns of characters or of vector elements, wherein the watermarked and potentially distorted or attacked document {hacek over (y)}′ is segmented, processed and the watermark extracted as ŵ, the codeword ĉ estimated, and the message {circumflex over (m)} decoded, the method comprising the steps of (a) applying document segmentation to the watermarked document {hacek over (y)}′, including the selection of documents text and/or vector graphics components y text , (b) extracting the potentially modulated elements from the text and/or vector graphics components, including performing character and/or elements segmentation for text and/or vector graphics documents, (c) estimating the watermark signal ŵ from the modulated grayscale, color and/or halftone pattern attributes, (d) generating a pilot signal; estimating and compensating the extracted watermark ŵ state and desynchronization, based on the pilot signal, resulting into the estimated codeword ĉ; decoding the codeword ĉ resulting into the final message {circumflex over (m)}. 16. The method of claim 11 wherein any watermark signal detection, estimation, channel state estimation and compensation, desynchronization estimation and compensation technique is applied to the extracted watermark ŵ in order to obtain the estimated codeword ĉ; wherein any decoding can be applied to the codeword ĉ to decode the message {circumflex over (m)}, including any ECC decoding; wherein optionally an auxiliary k aux is applied for watermark extraction and decoding.