Method and apparatus of autodiscriminating in symbol reader employing prioritized and updated table of symbologies

• US 6,095,422 A
• Filed: 08/26/1999
• Issued: 08/01/2000
• Est. Priority Date: 01/14/1998
• Status: Expired due to Term

• Current Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Original Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Inventors: Ogami, Kenneth Yuji
• Primary Examiner(s): Pitts, Harold I.
• Application Number:
  US09/383,483
• Time in Patent Office: 341 Days
• Field of Search: 235/462.27, 235/472.01, 235/494
• US Class Current: 235/462.27
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence

Abstract

A method and apparatus employs a weighted order stored in a weight table for automatically discriminating optical symbols which may be encoded in any one of at least two symbologies. The weighted order may be dynamically updated to reflect the distribution of symbologies as the symbols are acquired and decoded.

Claims

1. An automated method of decoding a number of symbols, the symbols being encoded in one of at least two symbologies, the method comprising the steps of:

acquiring a one of the symbols; and

successively applying a series of symbology translations to the acquired symbol in a weighted order until the acquired symbol is decoded.

2. The method according to claim 1, further comprising the step of periodically updating the weighted order.

3. The method according to claim 1, further comprising the step of periodically updating the weighted order to reflect the frequency with which symbols of each of the symbologies have been decoded.

4. The method according to claim 1, further comprising the step of:

maintaining a table of weights, the table of weights containing a weight for each of the symbologies.

5. The method according to claim 1, further comprising the steps of:

maintaining a table of weights, the table of weights containing a weight for each of the symbologies, each of the weights corresponding to a number of times each of the series of symbology translations has been successfully employed to decode one of the symbols; and

updating the table after each successful decode.

6. The method according to claim 1, further comprising the steps of:

maintaining a table of weights, the table of weights containing a weight for each of the symbologies, the table of weights containing a weight for each of the symbologies, the weight of each symbology corresponding to a frequency with which a symbol encoded in the symbology has occurred; and

updating the table after each successful decode.

7. The method according to claim 1, further comprising the steps of:

maintaining a table of weights, the table of weights containing a weight for each of the symbologies; and

selectively updating the table of weights in response to a user input.

8. The method according to claim 1, further comprising the steps of:

maintaining a table of weights, the table containing a weight for each of the symbologies, the weight of each of the symbologies corresponding to a frequency with which a symbol encoded in the symbology has occurred;

accepting a user weighting factor from a user input device; and

multiplying the weight from the table of weights and the user weighting factor to determine the weighted order.

9. A method of automatic discrimination to identify a symbology to which a symbol belongs, the method comprising the steps of:

assigning a weighted order to a plurality of symbologies;

iterating through a set of symbologies in order of weight while successively determining if the symbol belongs to one of the symbologies.

10. The method of claim 9, wherein the step of assigning a weighted order includes assigning a weight to each of the symbology translations, the weight corresponding to the frequency with which that symbology translation has decoded the symbol.

11. The method of claim 9, wherein the step of assigning a weighted order includes assigning a weight to each of the symbology translations, the weight corresponding to a product of the frequency with which that symbology translation has decoded the symbol and a weight factor.

12. The method of claim 9, wherein the step of assigning a weighted order includes assigning a weight to each of the symbology translations, the weight corresponding to a product of the frequency with which that symbology translation has decoded the symbol and a user updatable weight factor.

13. An automated discriminator for discriminating a set of data relating to a symbol, the set of data being produced by an optical scanner, the automated discriminator comprising:

a memory having an output port, the memory storing a set of symbology weight information;

a programmed computer having and output port and an input port which receives the set of data produced by the optical scanner and the set of symbology weight information from the memory, the computer being responsive to the set of symbology weight information to successively apply a set of transformations to the data received in a weighted order that corresponds to the set of symbology weight information.

14. The automated discriminator of claim 13, wherein the memory further comprises an input port, the input port of the memory in data communication with the output port of the computer and responsive to an update signal from the computer to update the set of symbology weight information stored in the memory for each set of data.

15. The automated discriminator of claim 13, further comprising:

a user interface in data communication with the memory for selectively updating the set of symbology weight information.

16. The automated discriminator of claim 13, wherein the memory further comprises an input port, the input port of the memory in data communication with the output port of the computer and responsive to an update signal from the computer to update the set of symbology weight information stored in the memory for each set of data, and wherein the automated discriminator further comprises a user interface in data communication with the memory for selectively updating the set of symbology weight information.

17. An article of manufacture having a computer readable program embodied therein for causing a set of data relating to a geometry of an optical symbol to be converted into a set of decoded data, the computer readable program in the article of manufacture comprising the steps of:

storing the set of data relating to a geometry of an optical symbol in a register;

successively applying a set of symbology transformations in a weighted order to the data stored in the register;

applying the set of symbology transformations until the data stored in the register is converted; and

updating the weighted order of the set of symbology transformations.

18. A method of operating a symbol reader, the method comprising the steps of:

scanning a symbol to acquire a digital representation of the symbol;

applying a series of symbology translations to the digital representation of the symbol in a weighted order.

19. The method according to claim 18, further comprising the step of:

periodically updating the weighted order of each of the symbology translations.

20. The method according to claim 19, wherein the step of periodically updating the weighted order includes:

maintaining a weighted average table, the weights in the weighted average table corresponding to a number of times that each of the symbology translations has been employed; and

updating the weights in the table after each decode of the symbol.

21. The method according to claim 19, wherein the step of periodically updating the weighted order includes

maintaining a weighted average table, the weights in the weighted average table corresponding to a value equal the product of a number of times that each of the symbology translations has been employed and a weighting factor;

and

updating the weights in the table after each successful decode of the symbol.

22. The method according to claim 19, wherein the step of periodically updating the weighted order includes

maintaining a weighted average table, the weights in the weighted average table equal to a product of a weighting formula having at least a first parameter corresponding to a number of times each of the symbology translations has been employed.

23. The method according to claim 19, further comprising the steps of:

maintaining a weighted average table corresponding to a number of times each symbology has be successfully employed to decode the symbols; and

selectively updating the weighted average table in response to a user input.

24. The method according to claim 18, further comprising the step of:

maintaining a weighted average table, the weights in the weighted average table corresponding to a value equal to the number of times each of the symbology translations has been employed multiplied by a user input weighting factor.

25. The method according to claim 18, further comprising the steps of:

maintaining a weighted average table, the weights in the weighted average table corresponding to the number of times each of the symbology translations has been employed; and

selectively updating the weighted average table in response to a user input.

26. A method of decoding symbols encoded in a plurality of symbologies, the method comprising the steps of:

acquiring data from a first symbol;

decoding the data from the first symbol based on a symbology determined from the plurality of symbologies;

updating a priority table to reflect the symbology of the first symbol;

acquiring data from a plurality of additional symbols;

for each of the symbols in the plurality of additional symbols, applying, in a prioritized order, the symbologies in the plurality of symbologies to the acquired data until the acquired data is decoded; and

updating the priority table each time a symbol is successfully decoded.

27. The method according to claim 26 wherein the step of

updating the priority table includes

incrementing a one of a plurality of count values, each of the count values corresponding to a respective one of the symbologies.

28. The method according to claim 26 wherein the step of

updating a priority table includes

incrementing a one of a plurality of count values, each of the count values corresponding to a respective one of the symbologies;

and

sorting the count values to defined a weighted order.

29. The method according to claim 26 wherein the step of

updating a priority table includes

defining a window size;

incrementing a one of a plurality of count values, each of the count values corresponding to a respective one of the symbologies;

for each window of symbols decoded, calculating a weighted sum for each of the symbologies, wherein the weighted sum is equal to a sum of an immediately prior weighted sum for the symbology divided by the widow size and the count value for the symbology divided by the window size.

30. The method according to claim 26 wherein the step of

updating a priority table includes

defining a window size;

incrementing a one of a plurality of count values, each of the count values corresponding to a respective one of the symbologies;

for each window of symbols decoded, calculating a weighted sum for each of the symbologies, wherein the weighted sum is equal to a sum of an immediately prior weighted sum for the symbology divided by the widow size and the count value for the symbology divided by the window size; and

for each symbology, calculating a rate value.

31. The method according to claim 26 wherein the step of

updating a priority table includes

defining a window size;

incrementing a one of a plurality of count values, each of the count values corresponding to a respective one of the symbologies;

for each window of symbols decoded, calculating a weighted sum for each of the symbologies, wherein the weighted sum is equal to a sum of an immediately prior weighted sum for the symbology divided by the widow size and the count value for the symbology divided by the window size;

calculating an average weight value; and

sorting the average weight values to defined a weighted order.

32. A method of decoding symbols encoded in a plurality of symbologies, the method comprising the steps of:

acquiring data from a first symbol;

decoding the data from the first symbol based on a symbology determined from the plurality of symbologies; and

updating a priority table to reflect the symbology of the first symbol.