Vector reconstruction of asynchronously captured tiled embedded data blocks

• US 5,694,102 A
• Filed: 12/21/1995
• Issued: 12/02/1997
• Est. Priority Date: 12/21/1995
• Status: Expired due to Fees

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Hecht, David L.
• Primary Examiner(s): Hajec, Donald T.
• Assistant Examiner(s): TREMBLAY, MARK STEPHEN
• Application Number:
  US08/577,672
• Time in Patent Office: 712 Days
• Field of Search: 235/494, 235/487, 235/456, 235/454, 235/462
• US Class Current: 235/456
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: H04L 25/00 Baseband systems

Abstract

To facilitate the recovery data from an embedded data pattern through the use of a appropriately sized capture window that is randomly positioned within the data pattern, the embedded data pattern is composed of a plurality of identical, one dimensionally or two dimensionally regularly tiled embedded data blocks which contain sufficient spatial addressing information to permit the logical reconstruction of a complete data block from any set of fragments that collectively provide a full cover for the surface area of any one tile. To this end, the capture window is sized to include a shape which is completely registered with the data pattern in which is capable of tiling the recording medium in accordance with the tiling vectors.

Claims

1. A process for capturing logically ordered digital values from a spatially asynchronous read out of a tiled data pattern that is composed of multiple, spatially synchronizeable instances of an encoding of said digital values;

said instances of said encoding being written on a recording medium on a spatially periodic lattice of centers and being mapped into essentially identical, two dimensional, non-overlapping data blocks in accordance with a layout rule which spatially formats that respective instances of said encoding identically within the respective data blocks;

said data blocks being tiled onto said recording medium in at least one direction in accordance with a tiling vector of deterministic length;

said read out of said data pattern including a region of said data pattern that is appropriately shaped for tiling said data blocks on to said recording medium in accordance with said tiling vector;

said process comprising the steps of

transforming said read out of said encoding into a two dimensional, correspondingly ordered, electronic representation of said read out;

replicating said electronic representation in accordance with said tiling vector to produce an extended representation of said read out that includes a representation of the encoding contained by at least one of said data blocks that is ordered in accordance with the spatial formatting of said encodings; and

synchronously reading out the representation of the encoding contained by said one data block in an order conforming to the spatial formatting of such encoding to return the digital values that are encoded thereby in said logical order.

2. The process of claim 1 wherein said electronic representation is a logic domain digital mapping of said read out.

3. The process of claim 2 wherein each of the synchronizeable instances of said encoding includes

a first set of machine recognizable symbols which are selected to encode respective ones of said digital values and ordered to preserve the logical ordering of said digital values;

and

a second set of machine recognizable symbols which are selected and ordered to encode a machine recognizable digital synchronization sequence;

said second set of symbols being written into deterministic locations within each of said data blocks to provide at least one spatial synchronization reference for each of said data blocks at a deterministic location therein.

4. The process of claim 3 wherein said first and second set of symbols are visually indistinguishable from each other.

5. The process of claim 4 wherein said symbols are slash-like marks which encode said digital values and said synchronization sequence in their angular orientation.

6. The process of claim 5 wherein

said digital values and said synchronization sequence are binary, and

said slash-like marks are oriented at approximately +45°

and -45°

with respect to and axis to encode binary 1'"'"'s and 0'"'"'s.

7. The process of claim 6 wherein said data blocks are rectangular and are written on spatially contiguous sets of centers on said recording medium.

8. The process of claim 1 wherein said electronic representation is a device dependent representation of said read out which substantially linearly scales to said read out in accordance with a deterministic scaling factor.

9. A process for capturing logically ordered digital values from a spatially asynchronous read out of a tiled data pattern that is composed of multiple, spatially synchronizeable instances of an encoding of said digital values;

said instances of said encoding being written on a recording medium on a spatially periodic lattice of centers and being mapped into essentially identical, two dimensional, non-overlapping data blocks in accordance with a layout rule which spatially formats that respective instances of said encoding identically within the respective data blocks;

said data blocks being tiled onto said recording medium in accordance with a pair of angularly separated tiling vectors of deterministic length;

said read out of said data pattern including a region of said data pattern that is appropriately shaped for tiling said data blocks on to said recording medium in accordance with said tiling vectors;

said process comprising the steps of

transforming said read out of said encoding into a two dimensional, correspondingly ordered, electronic representation of said read out;

replicating said electronic representation in accordance with each of said tiling vectors to produce an extended representation of said read out that includes a representation of the encoding contained by at least one of said data blocks that is ordered in accordance with the spatial formatting of said encodings; and

synchronously reading out the representation of the encoding contained by said one data block in an order conforming to the spatial formatting of such encoding to return the digital values that are encoded thereby in said logical order.

10. The process of claim 9 wherein said electronic representation said electronic representation is a logic domain digital mapping of said read out.

11. The process of claim 10 wherein each of the synchronizeable instances of said encoding includes

a first set of machine recognizable symbols which are selected to encode respective ones of said digital values and ordered to preserve the logical ordering of said digital values;

and

a second set of machine recognizable symbols which are selected and ordered to encode a machine recognizable digital synchronization sequence;

said second set of symbols being written into deterministic locations within each of said data blocks to provide at least one spatial synchronization reference for each of said data blocks at a deterministic location therein.

12. The process of claim 11 wherein said first and second set of symbols are visually indistinguishable from each other.

13. The process of claim 12 wherein said symbols are slash-like marks which encode said digital values and said synchronization sequence in their angular orientation.

14. The process of claim 13 wherein

said digital values and said synchronization sequence are binary, and

said slash-like marks are oriented at approximately +45°

and -45°

with respect to and axis to encode binary 1'"'"'s and 0'"'"'s.

15. The process of claim 14 wherein said data blocks are rectangular and are written on spatially contiguous sets of centers on said recording medium.