Universal Product Coding

1
Universal Product Coding

• Omar Hemmali
• Sunday, November 15, 2009

2
Objectives

• Define Universal Product Coding
• Define and talk about the history of barcoding
• Talk about the technical specifications of UPCs
• Talk about UPC error checking codes
• Talk about UPC-A to UPC-E compression and
  expansion
• Talk about the relation with Product Coding and
  Computer Science
• Briefly talk about the future of Product Coding

3
First off

• Universal Product Code UPC
• UPC is a GTIN
• GTINs are developed by GS1
• GS1 is the leading global organization to improve
  commerce efficiency

4
Humble beginnings

• Series of black and white bars
• Patent US 2,612,994
• Held by Norman Woodland and Bernard Silver
• Faster checkouts

5
Tech Spec

• Light and Dark bars to form Bar Sections
• Left side code is below
• Right side code is inverted

MFG code Item Code
Prefix Check digit
6
Physical Specs
1.469 Wide
0.25 Quiet
0.25 Quiet
1.020 High
0.065 Extended
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Check Digit

• Error checking code.
• Sum of odd positions times 3
• Sum of even positions
• Mod by 10
• (num 0)? 0 10-num

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Example

• Odds (0 6 0 2 1 5) 3 42
• Evens 3 0 0 9 4 16
• Add together then mod by 10
• 58 10 8
• Not 0, so 0 8 2

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Why it works

• In order to get correct check digit with
  incorrect code the sum must be off by 10
• Odds sum off by 9 and Evens sum off by 1
• Odds sum off by 6 and Evens sum off by 4
• Odds sum off by 3 and Evens sum off by 7
• Odds sum is correct but Evens sum off by 10

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Zero Compression

• Useful when limited space
• Often seen on Gum Packs and Soda Cans
• Has two prerequisites
• Must start with 0
• Has 4 consecutive 0s

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Four Rules
Rule 1
Rule 2
Rule 3
Rule 4
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Making it smaller
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Example

• Compress 012500000398
• Falls under rule 2.
• Take first three digits of Mfg code
• Append last two digits of item code
• Append 3
• 125343
• So full UPC-E number would be 0-125343-8

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Easy to expand

• 5 Pack Juicy fruit
• 02217303
• Get six digits 221730
• Falls under rule 1
• Expand to 0-2200000173-3
• Check digit is correct

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So what

• Ingenious data structure
• Compression/Expansion algorithm
• Error checking code
• Database lookup
• Centralized maintenance

16
To the future

• Five Mfg digits and five item digits
• Limited
• Use RFIDs
• Limitless possibilities
• Not reliable enough though

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Conclusion

• UPCs are data structures
• UPCs are maintained by GS1
• Very detailed specs about UPCs
• UPCs have built in error checking
• Some UPCs can be compressed
• New technologies that may make UPCs obsolete.

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What is that background?

• It is actually Agent 47s Barcode from the Hitman
  series.
• Translates to 640509040147

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Questions

• Expand the 6 digit UPC code of a 12oz Mountain
  Dew soda can and find its check digit.
• The 6 digit code is 120850

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Sources

• Wikipedia for images
• Google Images for Hitman image
• http//www.barcodesymbols.com/upca.htm
• http//www.barcodesymbols.com/upce.htm
• http//www.tkb-4u.com/code/barcode/upc.php
• http//www.insightu.org/hobby/matrix/matrix1.htm
• http//www.insightu.org/hobby/guide_mfr/ch10.htm1
  0.7_SellingUnit
• http//www.terrapin.co.uk/services/bcspecean13.htm
  l
• http//www.makebarcode.com/specs/upc_e.html
• http//barcodes.gs1us.org/dnn_bcec/TabId/142/Defau
  lt.aspx
• http//www.gs1.org/productssolutions/barcodes/tech
  nical/id_keys.html
• http//en.wikipedia.org/wiki/Agent_47
• http//www.informationweek.com/news/mobility/RFID/
  showArticle.jhtmljsessionidAXCCYPRLASWACQSNDLOSK
  HSCJUNN2JVN?articleID53200075_requestid245769
• http//www.barcodesymbols.com/information/barcodes
  .htm
• http//www.barcodesymbols.com/information/upc-numb
  ers.htm
• http//en.wikipedia.org/wiki/Global_Trade_Item_Num
  ber