Source data compression and decompression in code symbol printing and decoding

• US 5,764,774 A
• Filed: 09/25/1995
• Issued: 06/09/1998
• Est. Priority Date: 09/25/1995
• Status: Expired due to Fees

• Current Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Original Assignee: Intermec Corporation (Honeywell International Inc.)
• Inventors: Liu, Larry Lingnan
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): White, Carmen D.
• Application Number:
  US08/533,113
• Time in Patent Office: 988 Days
• Field of Search: 380/9, 380/49
• US Class Current: 380/269
• CPC Class Codes: H04L 2209/30 Compression, e.g. Merkle-Damgard construction
• CPC Class Codes: H04L 9/00 Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols

Abstract

A coded symbol encoding and decoding system and method provides improved efficiency and security by compressing and/or encrypting data prior to encoding the data into a coded symbol symbology. Prior to encoding the data into the coded symbol symbology, the encoding portion of the system compresses and/or encrypts the data. If compression decreases the size of the data by a given threshold, the system encodes the compressed data. Otherwise, the system encodes the uncompressed data. An unused character in the encoded data is used as a flag to indicate whether the data was compressed and/or encrypted. The encoded data is then printed as a coded symbol pattern. Conversely, the decoding portion reads the printed pattern, decodes the resulting data, and if necessary, decompresses and/or decrypts the data. Use of an unused character in the encoded data to indicate whether the data was compressed and/or encrypted allows the system and method to be used with existing symbologies. Separating the compression and the encodation processes allows the system and method to adapt to advances in compression and encodation techniques.

Claims

1. A system for encoding source data comprising:

data compressor means for compressing said source data;

source coding control means coupled to said data compressor means for computing a size of said source data and a size of said compressed data, comparing the size of said source data to the size of said compressed data, and outputting output data,

wherein said output data comprises said compressed data if the size of said source data exceeds the size of said compressed data by a given threshold, and

said output data comprises said source data if the size of said source data does not exceed the size of said compressed data by the given threshold; and

encoder means coupled to said data compressor means for encoding said output data according to a coded symbol symbology.

2. The system of claim 1 further including input control means coupled to said encoder means for appending data to said encoded output data.

3. The system of claim 2 wherein said input control means further comprises means for setting a flag in said encoded output data, said flag indicating that said appended data was appended to said encoded output data.

4. The system of claim 3 wherein said input control means further comprises means for determining whether said encoded output data includes unused data, and wherein if said encoded output data includes unused data, said unused data comprises said flag, and if said encoded output data does not include unused data, said appended data comprises said flag.

5. The system of claim 2 wherein said appended data comprises a compression type indicator.

6. The system of claim 2 further comprising data encryptor means coupled to said data compressor means for encrypting said source data.

7. The system of claim 6 wherein said appended data comprises an encryption type indicator.

8. A system for encoding source data into the form of a one or two dimensional bar code symbology, said symbology having a predefined structure, said system comprising:

data encryptor means for encrypting said source data;

encoder means coupled to said data encryptor means for encoding said encrypted data according to said bar code symbology; and

input control means coupled to said encoder means for appending data to said encoded data within an unused portion of said predefined structure, said appended data comprising an encryption type indicator.

9. The system of claim 8 wherein said input control means further comprises means for setting a flag in said encoded data, said flag indicating that said appended data was appended to said encoded output data.

10. A system for encoding source data comprising:

data encryptor means for encrypting said source data;

encoder means coupled to said data encryptor means for encoding said encrvpted data according to a coded symbol symbology; and

input control means coupled to said encoder means for appending data to said encoded data, said appended data comprising an encryption type indicator;

wherein said input control means further comprises means for setting a flag in said encoded data, said flag indicating that said appended data was appended to said encoded output data, and means for determining whether said encoded data includes unused data, and wherein if said encoded data includes unused data, said unused data comprises said flag, and if said encoded data does not include unused data, said appended data comprises said flag.

11. A system for decoding data representing a coded symbol pattern according to a predetermined symbology, said system comprising:

reader means for reading a coded symbol and producing encoded data representing said coded symbol, said encoded data comprising compression data,

decoder means coupled to said reader means for decoding said encoded data, and

source decoding control means coupled to said decoder means for decompressing said decoded data in accordance with said compression data, wherein said compression data comprises a compression type indicator included within an unused portion of said predetermined symbology.

12. A system for decoding data representing a coded symbol pattern according to a predetermined symbology, said system comprising:

reader means for reading a coded symbol and producing encoded data representing said coded symbol, said encoded data comprising compression data,

decoder means coupled to said reader means for decoding said encoded data, and

source decoding control means coupled to said decoder means for decompressing said decoded data in accordance with said compression data, wherein said compression data comprises a flag included within an unused portion of said predetermined symbology, indicating whether said compression data further comprises a compression type indicator.

13. A system for decoding data representing a coded symbol pattern according to a predetermined symbology, said system comprising:

reader means for reading a coded symbol and producing encoded data representing said coded symbol, said encoded data comprising compression data included within an unused portion of said predetermined symbology,

decoder means coupled to said reader means for decoding said encoded data,

source decoding control means coupled to said decoder means for decompressing said decoded data in accordance with said compression data, and

an interface control coupled to said decoder means for removing said compression data from said encoded data.

14. A system for decoding data representing a coded symbol pattern according to a predetermined symbology, said system comprising:

reader means for reading a coded symbol and producing encoded data representing said coded symbol, said encoded data comprising compression data included within an unused portion of said predetermined symbology,

decoder means coupled to said reader means for decoding said encoded data, and

source decoding control means coupled to said decoder means for decompressing said decoded data in accordance with said compression data, wherein said encoded data further comprises an encryption type indicator, and said source decoding control means further includes means for decrypting said decoded data stream in accordance with said encryption type indicator.

15. A system for decoding data representing a coded symbol pattern according to a predetermined symbology, said system comprising:

reader means for reading a coded symbol and producing encoded data representing said coded symbol, said encoded data comprising encryption data included within an unused portion of said predetermined symbology,

decoder means coupled to said reader means for decoding said encoded data, and

source decoding control means coupled to said decoder means for decrypting said decoded data in accordance with said encryption data, wherein said encryption data comprises an encryption type indicator.

16. A system for decoding data representing a coded symbol pattern according to a predetermined symbology, said system comprising:

reader means for reading a coded symbol and producing encoded data representing said coded symbol, said encoded data comprising encryption data included within an unused portion of said predetermined symbology,

decoder means coupled to said reader means for decoding said encoded data, and

source decoding control means coupled to said decoder means for decrypting said decoded data in accordance with said encryption data, wherein said encryption data comprises a flag indicating whether said encryption data further comprises an encryption type indicator.

17. A system for decoding data represented in the form of a one or two-dimensional bar code symbology, said symbology having a predefined structure, said system comprising:

reader means for reading a bar code symbol and producing encoded data representing said bar code symbol, said encoded data comprising encryption data included within an unused portion of said bar code symbology,

decoder means coupled to said reader means for decoding said encoded data,

source decoding control means coupled to said decoder means for decrypting said decoded data in accordance with said encryption data, and

an interface control coupled to said decoder means for removing said encryption data from said encoded data.

18. A system for encoding and decoding source data comprising:

data compressor means for compressing said source data;

source coding control means coupled to said data compressor means for computing a size of said source data and a size of said compressed data, comparing the size of said source data to the size of said compressed data, and outputting output data,

said output data comprising said compressed data if the size of said source data exceeds the size of said compressed data by a given threshold,

said output data comprising said source data if the size of said source data does not exceed the size of said compressed data by the given threshold; and

encoder means coupled to said source coding control for encoding said output data according to a coded symbol symbology,

decoder means for receiving and decoding said encoded data; and

source decoding control means coupled to said decoder means for decompressing said decoded data in accordance with said compression data.

19. A method for encoding source data comprising the steps of:

compressing said source data;

computing a size of said source data and a size of said compressed data;

comparing the size of said source data to the size of said compressed data;

outputting output data, wherein said output data comprises said compressed data if the size of said source data exceeds the size of said compressed data by a given threshold, and said output data comprises said source data if the size of said source data does not exceed the size of said compressed data by the given threshold; and

encoding said output data according to a coded symbol symbology.

20. The method of claim 19 further comprising the step of appending data to said encoded output data, said appended data comprising a compression type indicator.

21. The method of claim 20 further comprising the step of setting a flag in said encoded output data, said flag indicating that said appended data was appended to said encoded output data.

22. The method of claim 21 further comprising the step of determining whether said encoded output data includes unused data, and wherein if said encoded output data includes unused data, said unused data comprises said flag, and if said encoded output data does not include unused data, said appended data comprises said flag.

23. A method for encoding source data comprising the steps of:

encrypting said source data;

encoding said encrypted data according to a coded symbol symbology having a predefined structure; and

appending data to said encoded data, said appended data comprising an encryption type indicator.

24. The method of claim 23 further comprising the step of setting a flag in said encoded data, said flag indicating that said appended data was appended to said encoded output data.

25. A method for encoding source data comprising the steps of:

encrypting said source data;

encoding said encrypted data according to a coded symbol symbology;

appending data to said encoded data, said appended data comprising an encryption type indicator;

setting a flag in said encoded data, said flag indicating that said appended data was appended to said encoded output data; and

determining whether said encoded data includes unused data, and wherein if said encoded data includes unused data, said unused data comprises said flag, and if said encoded data does not include unused data, said appended data comprises said flag.

26. A method for decoding data representing a coded symbol pattern comprising the steps of:

reading a coded symbol encoded in a given symbology and producing encoded data representing said coded symbol, said encoded data comprising compression data included in an unused portion of said symbology,

decoding said encoded data according to said given symbology, and

decompressing said decoded data in accordance with said compression data, wherein said compression data comprises a compression type indicator.

27. The method of claim 26 wherein said compression data comprises a flag indicating whether said compression data further comprises a compression type indicator.

28. The method of claim 27 further comprising the step of removing said compression data from said encoded data.

29. A method for decoding data representing a coded symbol pattern comprising the steps of:

reading a coded symbol encoded in a given symbology and producing encoded data representing said coded symbol, said encoded data comprising encryption data included in an unused portion of said symbology,

decoding said encoded data in accordance with said symbology, and

decrypting said decoded data in accordance with said encryption data, wherein said encryption data comprises an encryption type indicator.

30. A method for decoding data representing a coded symbol pattern comprising the steps of:

reading a coded symbol encoded in a given symbology and producing encoded data representing said coded symbol, said encoded data comprising encryption data included within an unused portion of said symbology,

decoding said encoded data in accordance with said symbology, and

decrypting said decoded data in accordance with said encryption data, wherein said encryption data comprises a flag indicating whether said encryption data further comprises an encryption type indicator.

31. A method for decoding data representing a coded symbol pattern comprising the steps of:

reading a coded symbol encoded in a given symbology and producing encoded data representing said coded symbol, said encoded data comprising encryption data included within an unused portion of said symbology,

decoding said encoded data in accordance with said symbology,

decrypting said decoded data in accordance with said encryption data, and

removing said encryption data from said encoded data.