Method of encoding data in a monochrome media

#This invention generally relates to a method for long-term preservation of data and more particularly relates to preservation of data associated with an image on monochrome media.

#In spite of numerous advances in development and use of color imaging media, there are a number of conditions in which monochrome imaging media must be used. For example, archival or long-term preservation of images may require that images be stored on a monochrome media. As another example, there can be advantages to compact storage of images, where it is desirable to use a monochrome media for preserving a color image, with accompanying encoded information.

#There can be a considerable amount of data associated with an image, where the data concerns the image itself. For example, in printing applications information about an image can include color separation data for corresponding cyan, magenta, yellow, and black (CMYK) inks or other colorants. Typically, color separations can be stored as separate images on monochrome media, so that each color separation is then stored as a separate monochrome image. For example, U.S. Pat. No. 5,335,082 (Sable) discloses an apparatus using a plurality of monochrome images as separations of a composite color image. Similarly, U.S. Pat. No. 5,606,379 (Williams) discloses a method for storing color images on a monochrome photographic recording medium in which separate R, G, and B or lightness and chroma channels are stored as separate images. Such methods may be acceptable for some types of storage environments, however, it can be appreciated that there would be advantages in storing fewer images and in providing a more compact arrangement.

#While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter of the present invention, it is believed that the invention will be better understood from the following description when taken in conjunction with the accompanying drawings, wherein:

#FIG. 1 is a block diagram showing the overall process by which a document can be preserved along with its associated encoded data;

#FIG. 2 is a flow chart illustrating key steps in processing for document preservation with associated encoded data;

#The present description is directed in particular to elements forming part of, or cooperating more directly with, apparatus in accordance with the invention. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art.

#Referring to FIG. 1, there is shown a preservation system 80 for accepting an input document and its associated data, encoding the data, and writing the rasterized image and data encoding onto a monochrome preservation medium to generate a preserved document record 90. A control processing unit 88, typically a computer workstation, accepts an input document in electronic form from any of a number of possible sources. One input source could be a networked graphics workstation 82. Alternately, an input document could be from a printed page 84, photograph, or other printed image that can be converted to electronic form by a scanner 86. Other possible document sources could include, but are not limited to, digital camera images, Photo CD images, on-line image archives, computer-generated images such as from CAD and graphics design software packages and multimedia software packages, document processing systems, and imaging instruments, for example. Documents could include data files of many types, including web pages, spreadsheets, email, electronic files from programs such as Microsoft Word, PowerPoint, Excel, and the like.

#Control processing unit 88 accepts the document data from any suitable source and formats image data into a rasterized form suitable for a printer 92. In rasterized form, the document is converted into one or more images. Each rasterized image comprises a two-dimensional array of pixels, with each pixel having an assigned value, such as a tristimulus color value, for example. In addition, control processing unit 88 may also format, encode, and rasterize additional data or metadata to be associated with the document and to be imaged along with the document onto preserved image record 90. This additional data or metadata may be provided by software that executes on control processing unit 88 itself or may be provided from graphics workstation 82 or from some other data source. This data or metadata could include information entered by a user or customer of preservation system 80.