Distributed state flags or other unordered information for embedded data blocks

• US 5,611,575 A
• Filed: 01/03/1995
• Issued: 03/18/1997
• Est. Priority Date: 01/03/1995
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Petrie, Glen W.
• Primary Examiner(s): Fridie, Jr., Willmon
• Application Number:
  US08/367,981
• Time in Patent Office: 805 Days
• Field of Search: 283/67, 283/70, 283/74, 283/76, 283/93, 283/113, 283/114, 283/901, 283/72
• US Class Current: 283/67
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 7/143 Glyph-codes
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0081 whereby both original and watermarked images are required at decoder, e.g. destination-based, non-blind, non-oblivious
• CPC Class Codes: Y10S 283/901 Concealed data

Abstract

An embedded data block for storing machine readable information on a recording medium has a lattice-like sync frame which defines the outer boundaries of individual, fixed-size frame blocks. Flags, which are encoded by embedded data characters on the sync frame, indicate whether there are any special processing instructions (e.g., user-specific or application-specific instructions for customizing the processing of the data block) encoded within the frame blocks.

Claims

1. A two dimensional embedded data block for storing machine readable information on a recording medium;

said embedded data block comprising a synchronization frame including at least on embedded data character for encoding a flag;

said flag having one state when said embedded data block contains an optional special processing codeword and a second state in the absence of such a codeword;

said special processing codeword being reserved for encoding custom instructions for processing said embedded data block.

2. The embedded data block of claim 1 wherein said embedded data block is composed of a self-clocking glyph code.

3. The embedded data block of claim 2 wherein said glyph code is composed of slash-like symbols, said symbols being written on said recording medium on substantially uniformly spaced centers.

4. The embedded data block of claim 3 wherein said glyph code has a substantially uniform grayscale appearance when viewed under ordinary viewing conditions.

5. A process for recording machine readable information on a recording medium, said process comprising the steps of

encoding said information in a two-dimensional embedded data block, said embedded data block being composed of embedded data characters, including characters that define a synchronization frame;

and encoding at least one of the embedded data characters on said synchronization frame to provide a flag which has one state when said embedded data block contains an optional special processing codeword and a second state in the absence of such a codeword;

said special processing codeword being reserved for encoding custom instructions for processing said embedded data block.

6. The embedded data block of claim 5 wherein said embedded data block is composed of a self-clocking glyph code.

7. The embedded data block of claim 6 wherein said glyph code is composed of slash-like symbols, said symbols being written on said recording medium on substantially uniformly spaced centers.

8. The embedded data block of claim 7 wherein said glyph code has a substantially uniform grayscale appearance when viewed under ordinary viewing conditions.