The present invention relates generally to hiding a signal in video. One
form of hiding is steganographic encoding. In one implementation a method
is provided including: receiving content data including a frame of image
data comprised of plural pixels, each comprising at least one value; for
each of plural pixels in said frame, determining a parameter associated
with the pixel, said parameter relating to the amount the pixel value may
be changed without noticeably impairing the appearance of the image data
when rendered to a viewer; altering plural pixels in said frame to hide
auxiliary data therein, the altering of each said pixel taking into
account the parameter associated therewith, so as to yield encoding that
conveys said auxiliary data without noticeably impairing the image data
when rendered to the viewer; and including with the content data, but
distinct from the pixels thereof, additional data that provides
information about the content data; wherein said auxiliary data and said
additional data cooperatively convey information about said content.
Other implementations and combinations are provided as well.