In a photographic processing method, an image unit having a plurality of
printable image frames is received. The image frames include a data frame
having subchannel information. An indicator of the presence of the
subchannel information is detected. A bitstream of all of the image
frames is generated. Responsive to the indicator, the data frame is
extracted from the bitstream and subchannel information is read from the
data frame. Fulfillment of image frames of the bitstream is provided in
accordance with the subchannel information. If no indicator is detected,
then the image frames are fulfilled in accordance with a different,
default subchannel.