Produce recognition system and method

• US 6,845,910 B2
• Filed: 06/12/2002
• Issued: 01/25/2005
• Est. Priority Date: 07/28/1999
• Status: Expired due to Term

• Current Assignee: NCR Voyix Corporation
• Original Assignee: NCR Corporation
• Inventors: Gu, Yeming, Collins, Jr., Donald A.
• Primary Examiner(s): Frech, Karl D.
• Application Number:
  US10/170,304
• Publication Number:
  US 20020179710A1
• Time in Patent Office: 958 Days
• Field of Search: 235/454, 235/455, 356/302, 356/328
• US Class Current: 235/454
• CPC Class Codes: G01J 3/0272 Handheld
• CPC Class Codes: G01J 3/28 Investigating the spectrum using colour filters G01J3/51
• CPC Class Codes: G01J 3/50 using electric radiation detectors
• CPC Class Codes: G01J 3/501 Colorimeters using spectrally-selective light sources, e.g. LEDs
• CPC Class Codes: G01J 3/502 using a dispersive element, e.g. grating, prism
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: G01J 3/524 Calibration of colorimeters
• CPC Class Codes: G01N 21/276 with alternation of sample and standard in optical path
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06V 20/68 Food, e.g. fruit or vegetables
• CPC Class Codes: G07G 1/0054 with control of supplementary check-parameters, e.g. weight or number of articles

Abstract

A produce recognition system and method which use an internal reference to calibrate a produce data collector. The produce data collector collects first data from an external reference, collects second and third data from an internal reference, and collects fourth data from a produce item. A computer determines a first calibration value from the first and second data and a second calibration value from the third data and applies the first and second calibration values to the fourth data to produce fifth data. The computer further obtains sixth data from reference produce data and compares the fifth and sixth data to identify the produce item.

Claims

1. A method of identifying a produce item comprising the steps of:

(a) obtaining calibration information for a produce data collector;

(b) collecting first data describing the produce item by the produce data collector;

(c) applying the calibration information to the first data to produce second data;

(d) obtaining a number of previously stored third data associated with a plurality of produce items;

(e) comparing the second data to the third data to determine fourth data and a corresponding produce item from the third data which is most like the second data; and

(f) identifying the produce item to be the corresponding produce item.

2. A method of identifying a produce item comprising the steps of:

(a) calibrating a produce data collector using an internal reference;

(b) collecting first data describing the produce item by the produce data collector;

(c) obtaining a number of previously stored second data associated with a plurality of produce items;

(d) comparing the first data with the second data;

(e) determining third data and a corresponding produce item from the second data which is most like the first data; and

(f) identifying the produce item to be the corresponding produce item.

3. A method of calibrating produce data collected by a produce data collector comprising the steps of:

(a) obtaining a first calibration value for the produce data collector using an external reference and an internal reference;

(b) obtaining a second calibration value for the produce data collector using only the internal reference; and

(c) applying the first and second calibration values to the produce data.

4. A method of identifying an item comprising the steps of:

(a) obtaining calibration information for a spectrometer;

(b) collecting first data describing the item by the spectrometer;

(c) applying the calibration information to the first data to produce second data;

(d) obtaining a number of previously stored third data associated with a plurality of items;

(e) comparing the second data to the third data to determine fourth data and a corresponding item from the third data which is most like the second data; and

(f) identifying the item to be the corresponding item.

5. The method as recited in claim 4, wherein step a comprises the substeps of:

(a-1) obtaining a first calibration value for the spectrometer which is substantially permanent; and

(a-2) obtaining a second calibration value for the spectrometer which is temporary.

6. The method as recited in claim 5, wherein step a-1 comprises the substeps of:

(a-1-A) measuring a first spectrum reflected from a first reference external to the spectrometer;

(a-1-B) measuring a second spectrum reflected from a second reference internal to the spectrometer; and

(a-1-C) determining the ratio of the first spectrum to the second spectrum to obtain the first calibration value.

7. The method as recited in claim 5, wherein step a-1 comprises the substep of:

(a-1-A) obtaining the first calibration value during manufacture of the spectrometer.

8. The method as recited in claim 5, wherein step a-1 comprises the substep of:

(a-1-A) obtaining the first calibration value during installation of the spectrometer.

9. The method as recited in claim 5, wherein step a-1 comprises the substep of:

(a-1-A) obtaining the first calibration value from a computer coupled to the spectrometer.

10. The method as recited in claim 5, wherein step a-1 comprises the substep of:

(a-1-A) obtaining the first calibration value from a memory within the spectrometer.

11. The method as recited in claim 5, wherein step a-2 comprises the substep of:

(a-2-A) obtaining the second calibration value from a computer coupled to the spectrometer.

12. The method as recited in claim 5, wherein step a-2 comprises the substep of:

(a-2-A) obtaining the second calibration value from a memory within the spectrometer.

13. The method as recited in claim 5, wherein step a-2 comprises the substeps of:

(a-2-A) determining whether a previous second calibration value is available; and

(a-2-B) if a previous second calibration value is not available, measuring a spectrum reflected from a reference internal to the spectrometer.

14. The method as recited in claim 5, wherein step a-2 comprises the substep of:

(a-2-A) periodically measuring a spectrum reflected from a reference internal to the spectrometer based upon a predetermined calibration schedule.

15. The method as recited in claim 5, wherein step a-2 comprises the substep of:

(a-2-A) measuring a spectrum reflected from a reference internal to the spectrometer in response to recordation of an operator command at a computer coupled to the spectrometer.

16. The method as recited in claim 5, wherein step a-2 comprises the substep of:

(a-2-A) measuring a spectrum reflected from a reference internal to the spectrometer in response to activation of a switch coupled to the spectrometer by an operator.

17. The method as recited in claim 4, wherein step b comprises the substeps of:

(b-1) illuminating the item;

(b-2) splitting light collected from the item into a plurality of different light portions in different wavelength bands;

(b-3) converting energy in the plurality of light portions into a plurality of electrical signals; and

(b-4) digitizing the plurality of electrical signals to produce the first data.

18. The method as recited in claim 4, wherein step b comprises the substeps of:

(b-1) determining whether the item is adjacent the spectrometer; and

(b-2) if the item is adjacent the spectrometer, collecting the first data from the item.

19. The method as recited in claim 4, wherein step b comprises the substeps of:

(b-1) receiving a signal from a computer coupled to the spectrometer in response to operator input; and

(b-2) collecting the first data from the item in response to the signal.

20. The method as recited in claim 4, wherein step c comprises the substep of:

(c-1) normalizing the first data using the first and second calibration values.

21. The method as recited in claim 4, wherein step c comprises the substep of:

(c-1) normalizing the first data by dividing the first data by the first and second calibration values.

22. The method as recited in claim 4, further comprising the step of:

(g) converting pixel information in the second data to second wavelength information.

23. The method as recited in claim 22, wherein step e comprises the substeps of:

(e-1) comparing the second wavelength information in the second data with third wavelength information in the third data to determine fourth wavelength information in fourth data and a corresponding item from the third data which is most like the second wavelength information.

24. The method as recited in claim 22, wherein step g comprises the substeps of:

(g-1) mapping the pixel information in the first data to the wavelength information; and

(g-2) interpolating the wavelength information between a minimum wavelength and a maximum wavelength.

25. The method as recited in claim 22, wherein step g comprises the substep of:

(g-1) mapping the pixel information in the first data to the wavelength information using an intrinsic mapping function of the spectrometer.

26. The method as recited in claim 22, wherein step g comprises the substeps of:

(g-1) obtaining constant values within an intrinsic mapping function of the spectrometer from a memory within the spectrometer; and

(g-2) mapping the pixel information in the first data to the wavelength information using the intrinsic mapping function.

27. The method as recited in claim 4, wherein step g comprises the substeps of:

(g-1) obtaining constant values within an intrinsic mapping function of the spectrometer from a computer coupled to the spectrometer; and

(g-2) mapping the pixel information in the first data to the wavelength information using the intrinsic mapping function.

28. The method as recited in claim 4, wherein step d comprises the substep of:

(d-1) loading the second data from a computer coupled to the spectrometer.

29. The method as recited in claim 4, wherein step f comprises the substep of:

(f-1) determining a list of items associated with the second data whose second wavelength data are most like the first data;

(f-2) displaying the list of items; and

(f-3) recording an operator choice for one of the items from the list.

30. A method of identifying an item comprising the steps of:

(a) obtaining a first calibration value for a spectrometer which is substantially permanent;

(b) obtaining a second calibration value for the spectrometer which is temporary;

(c) collecting first data describing the item by the spectrometer;

(d) applying the first and second calibration values to the first data to produce second data;

(e) converting pixel information in the second data to second wavelength information;

(f) obtaining a number of previously stored third data associated with a plurality of items; and

(g) comparing the second wavelength information in the second data with third wavelength information in the third data to determine fourth wavelength information in fourth data and a corresponding item from the third data which is most like the second wavelength information; and

(h) identifying the item to be the corresponding item.

31. A method of identifying an item comprising the steps of:

(a) calibrating a spectrometer using an internal reference;

(b) collecting first data describing the item by the spectrometer;

(c) obtaining a number of previously stored second data associated with a plurality of items;

(d) comparing the first data with the second data;

(e) determining third data and a corresponding item from the second data which is most like the first data; and

(f) identifying the item to be the corresponding item.

32. A method of calibrating item data collected by a spectrometer comprising the steps of:

(a) obtaining a first calibration value for the spectrometer using an external reference and an internal reference;

(b) obtaining a second calibration value for the spectrometer using only the internal reference; and

(c) applying the first and second calibration values to the item data.

33. The method as recited in claim 32, wherein step a comprises the substeps of:

(a-1) measuring a first spectrum reflected from the external reference;

(a-2) measuring a second spectrum reflected from the internal reference; and

(a-3) determining the ratio of the first spectrum to the second spectrum to obtain the first calibration value.

34. The method as recited in claim 33, wherein step a-1 comprises the substeps of:

(a-1 -A) illuminating the external reference through a window of the spectrometer; and

(a-1-B) collecting spectrum data from the external reference.

35. The method as recited in claim 33, wherein step a-2 comprises the substeps of:

(a-2-A) placing the internal reference in a light path within the spectrometer;

(a-2-B) illuminating the internal reference;

(a-2-C) collecting spectrum data from the internal reference; and

(a-2-D) removing internal reference from the light path.

36. The method as recited in claim 32, wherein step a comprises the substep of:

(a-1) obtaining the first calibration value during manufacture of the spectrometer.

37. The method as recited in claim 32, wherein step a comprises the substep of:

(a-1) obtaining the first calibration value during installation of the spectrometer.

38. The method as recited in claim 32, wherein step a comprises the substep of:

(a-1) obtaining the first calibration value from a computer coupled to the spectrometer.

39. The method as recited in claim 32, wherein step a comprises the substep of:

(a-1) obtaining the first calibration value from a memory within the spectrometer.

40. The method as recited in claim 32, wherein step b comprises the substep of:

(b-1) obtaining the second calibration value from a computer coupled to the spectrometer.

41. The method as recited in claim 32, wherein step b comprises the substep of:

(b-1) obtaining the second calibration value from a memory within the spectrometer.

42. The method as recited in claim 32, wherein step b comprises the substeps of:

(b-1) determining whether a previous second calibration value is available; and

(b-2) if a previous second calibration value is not available, measuring a spectrum reflected from the internal reference.

43. The method as recited in claim 32, wherein step b comprises the substep of:

(b-1) periodically measuring a spectrum reflected from the internal reference based upon a predetermined calibration schedule.

44. The method as recited in claim 32, wherein step b comprises the substep of:

(b-1) measuring a spectrum reflected from the internal reference in response to recordation of an operator command at a computer coupled to the spectrometer.

45. The method as recited in claim 32, wherein step b comprises the substep of:

(b-1) measuring a spectrum reflected from the internal reference in response to activation of a switch coupled to the spectrometer by an operator.

46. The method as recited in claim 32, wherein step b comprises the substeps of:

(b-1) placing the internal reference in a light path within the spectrometer;

(b-2) illuminating the internal reference;

(b-3) collecting spectrum data from the internal reference; and

(b-4) removing internal reference from the light path.

47. The method as recited in claim 46, wherein step b further comprises the substep of:

(b-5) storing the spectrum data.