This patent document relates generally to steganography and digital watermarking. One claim recites an apparatus comprising: electronic memory for buffering samples corresponding to a digital image; means for analyzing a digital image relative to an expected workflow process, the expected workflow process comprising optical capture of a printed version of the digital image, the digital image comprising data representing process colors CMY; means for applying tone correction to the digital image, said means for applying yielding an altered digital image; means for transforming the altered digital image with digital watermarking, the digital watermarking conveying a plural-bit message; and a processor configured for providing the transformed, altered digital image. Of course, other claims and combinations are provided too.