A method for including additional data, such as identifying text, within a
stored digital image, the additional data being hidden from view when the
image is displayed. The method includes the step of identifying a region
within the digital image which contains picture elements, or pixels,
having either a constant intensity, hue or saturation value, or a random
distribution of such values for the storage of "hidden" data. An pixel
value is determined which differs slightly or blends well with the values
contained within the image region into which the hidden data is to be
written; and the additional data is saved within the constant or random
content image region at this determined intensity value. The intensity
value utilized for the encoding of the hidden data or text, although
differing slightly from the intensity values of the background pixels
within the image region into which the hidden data or text is written, is
selected such that the difference between the pixel value of the
background and the pixel value of the hidden data is indiscernible when
the image is viewed by the human eye. The hidden data stored with the
digital image may be identifying text which can be used to aid in the
storage, recognition, classification, recovery and retrieval of digital
images within a multimedia database.