An image processing apparatus is operable to embed data into an image.
Images such as those generated from an inter-laced scan may comprise a
frame of image data, the frame comprising first and second image fields.
The image processing apparatus comprises a combining processor operable
to introduce the data to be embedded into at least one of the first and
second fields of the image frame. As such a likelihood of a perceivable
effect of the embedded data on the image may be reduced, because the
images are viewed as a frame. The embedded data may also have an
increased likelihood of being detected because some processing may effect
the image frame more then the fields of the image. The combining
processor may be operable to represent the data to be embedded in a
transform domain form, and, in combination with a transform processor,
combine the data to be embedded with the first and/or second fields with
the image in a transform domain form or a spatial domain form. The
transform domain may provide a plurality of sub-bands and the data to be
embedded may be introduced into at least one of the sub-bands of the
transform domain form of the first and/or second fields of the image.
Furthermore, the combining processor may be operable to introduce data to
be embedded into at least one other sub-band, and the combining processor
may be operable in combination with the transform processor to combine
the data in the other sub-band with the frame of image data in the
transform or the spatial domain.