METHOD OF AND APPARATUS FOR AUTOMATICALLY CROPPING CAPTURED LINEAR IMAGES OF A MOVING OBJECT PRIOR TO IMAGE PROCESSING USING REGION OF INTEREST (ROI) COORDINATE SPECIFICATIONS CAPTURED BY AN OBJECT PROFILING SUBSYSTEM

• US 6,837,432 B2
• Filed: 03/14/2002
• Issued: 01/04/2005
• Est. Priority Date: 03/24/1998
• Status: Expired due to Term

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Zhu, Xiaoxun, Knowles, C. Harry, Au, Ka Man, Ghosh, Sankar, Tsikos, Constantine J.
• Primary Examiner(s): Le, Thien M.
• Application Number:
  US10/099,142
• Publication Number:
  US 20030062414A1
• Time in Patent Office: 1,027 Days
• Field of Search: 23546201-46248, 235/472.01, 235/472.02, 235/472.03, 235/494, 235/454, 235/455
• US Class Current: 235/462.01
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0052 the light source comprising a laser diode coupling into light guides using intermediate optical elements G02B6/4204; semiconductor lasers having optical devices external to the laser cavity H01S5/005
• CPC Class Codes: G02B 19/0085 for use with both a detector and a source , e.g. in a transceiver, G02B19/009, G02B19/0095 take precedence
• CPC Class Codes: G02B 19/009 for use with infrared radiation
• CPC Class Codes: G02B 19/0095 for use with ultraviolet radiation
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 27/095 Refractive optical elements
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: G06K 7/10 by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
• CPC Class Codes: G06K 7/10594 Beam path
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/146 the method including quality enhancement steps
• CPC Class Codes: G06Q 10/00 Administration; Management
• CPC Class Codes: G06Q 30/00 Commerce
• CPC Class Codes: G06V 20/62 Text, e.g. of license plates, overlay texts or captions on TV images
• CPC Class Codes: G06V 30/144 using a slot moved over the image; using discrete sensing elements at predetermined points; using automatic curve following means
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/4025 Array arrangements, e.g. constituted by discrete laser diodes or laser bar H01S5/42 takes precedence

Abstract

A method of and system for automatically cropping linear images of a moving object is disclosed. The method comprises automatically capturing a linear range and intensity data map from an object moving with respect to a coordinate reference system. The linear range and intensity data map includes a sequence of data sets taken along a sequence of sample points along the moving object. Each data set includes a set of coordinates specifying the location of the sample point and an intensity value specifying the intensity of light reflected from the moving object at the sample point. The intensity values in the linear range and intensity data map are automatically analyzed so as to determine the coordinates associated with a region of interest (ROI) on the moving object bearing object identifying information (e.g. bar code symbol, textual information, graphics, etc.) A linear image of the object moving within the coordinate reference is automatically captured. The coordinates of the region of interest (ROI) are automatically converted into a set of pixel indices corresponding to the region of interest (ROI) present in the linear image. The set of pixel indices and the linear image are then used to automatically produce a cropped linear image of the moving object. Cropped linear images can be buffered to produce two-dimensional images of the moving object, and then the two-dimensional image can be processed using image-based bar code decoding and/or OCR operators. By virtue of the present invention, it is now possible to crop linear images prior to image processing, on a linear image by linear image basis, thereby substantially reducing the amount of image data that requires image processing. By reducing image data through the cropping operations of the present invention, significant computational savings is achieved.

Claims

1. A method of automatically cropping linear images of a moving object, said method comprising the steps of:

(a) automatically capturing a linear range and intensity data map from an object moving with respect to a coordinate reference system, wherein said lenear range and intensity data map includes a sequence of data sets taken along a sequence of sample points along said object, and whereing each said data set includes a set of coordinates specifying the location of the sample point and an intensity value specifying the intensity of light reflected from said object at said sample point;

(b) automatically analyzing the intensity values in said linear range and intensity data map captured in step (a) so as to determine the coordinates associated with a region of interest (ROI) on said object bearing object identifying information;

(c) automatically capturing a linear image of said object moving within said coordinate reference system;

(d) automatically converting said coordinates of the region of interest (ROI) determined in step (b) into a set of pixel indices corresponding to said region of interest present in said linear image captured in step (c); and

(e) using said set of pixel indices determined in step (d) and said linear image captured in step (c), to automatically produce a cropped linear image of said object.

2. The method of claim 1, wherein step (a) comprises producing and scanning an amplitude modulated (AM) laser scanning beam across said object so as to collect said sequence of sample points along said object.

3. The method of claim 1, wherein step (a) comprises producing said sequence of data sets using one or more of structured laser illumination, CCD imaging and triangulation measurement techniques.

4. The method of claim 1, wherein step (c) comprises projecting a planar laser illumination beam (PLIB) onto said moving object during linear imaging operations.

5. The method of claim 1, which further comprises:

(f) buffering said cropped linear image of said object.

6. The method of claim 1, which further comprises repeating steps (a) through (e) a plurality of times, so as to produce a plurality of sequentially produced cropped linear images, which are then buffered in a 2-D memory array and then processed using image-based bar code symbol decoding and/or OCR-based image processing operators.

7. The method of claim 1, wherein said object bearing object identifying information is indicium selected from the group consisting of a bar code symbol, textual information, and graphics.

8. The method of claim 1, wherein said object is a package being transported along a conveyor belt structure.

9. A system for automatically cropping linear images of a moving object, said system comprising:

an object profiling subsystem for projecting a light beam towards an object moving past said object profiling subsystem, collecting light reflected from said moving object and detecting the intensity of said collected light to produce an intensity signal, and processing said intensity signal so as to produce a linear range and intensity data map which includes a sequence of data sets taken along a sequence of sample points along said moving object, and wherein each said data set includes a set of coordinates specifying the location of the sample point and an intensity value specifying the intensity of light reflected from said object at said sample point, said object profiling subsystem further including means for automatically analyzing the intensity values in said linear range and intensity data map so as to determine the set of coordinates associated with a region of interest (ROI) on said object bearing object identifying information;

a linear imaging subsystem having a linear imaging formation and detection module for capturing a linear image of said object; and

a control computer having means for receiving said linear image and said coordinates of said region of interest (ROI), means for converting the coordinates of said region of interest (ROI) into a set of pixel indices corresponding with said region of interest present in said linear image, and means for transmitting said linear image and said set of pixel indices to an image processing computer operably connected to said control computer;

wherein said image processing computer uses said set of pixel indices and said linear image to automatically produce a cropped linear image of said object.

10. The system of claim 9, wherein said object profiling subsystem comprises a laser scanning mechanism for producing and scanning an amplitude modulated (AM) laser scanning beam across said object so as to collect said sequence of sample points along said object.

11. The system of claim 9, wherein said object profiling subsystem comprises a mechanism for producing said sequence of data sets using one or more of structured laser illumination, CCD imaging and triangulation measurement techniques.

12. The system of claim 9, wherein said linear imaging subsystem comprises a mechanism for projecting a planar laser illumination (PLIB) onto said moving object during linear imaging operations.

13. The system of claim 9, wherein a plurality of linear range and intensity data maps and a plurality of linear images are sequentially produced within said system, and using said plurality of linear range and intensity data maps and said plurality of linear images, said image processing computer produces a plurality of cropped linear images which are buffered in a 2-D memory array and then processed using image-based bar code symbol decoding and/or OCR-based image processing operations.

14. The system of claim 9, wherein said object bearing object identifying information is indicium selected from the group consisting of a bar code symbol, textual information, and graphics.

15. The system of claim 9, wherein said object is a package being transported along a conveyor belt structure.

16. The system of claim 9, wherein said object profiling subsystem, said linear imaging subsystem, and said control computer are contained within a single housing.

17. A system for automatically cropping linear images of a moving object, said system comprising:

an object profiling subsystem for projecting a light beam towards an object moving past said object profiling subsystem, collecting light reflected from said moving object and detecting the intensity of said collected light to produce an intensity signal, and processing said intensity signal so as to produce a linear range and intensity data map which includes a sequence of data sets taken along a sequence of sample points along said moving object, and wherein each said data set includes a set of coordinates specifying the location of the sample point and an intensity value specifying the intensity of light reflected from said object at said sample point, said object profiling subsystem further including means for automatically analyzing the intensity values in said linear range and intensity data map so as to determine the set of coordinates associated with a region of interest (ROI) on said object bearing object identifying information;

a linear imaging subsystem having a linear imaging formation and detection module for capturing a linear image of said object; and

a camera control computer having a first means for receiving said linear image and said coordinates of said region of interest (ROI), a second means for converting the coordinates of said region of interest (ROI) into a set of pixel indices corresponding with said region of interest present in said linear image, and a third means for automatically producing a cropped linear image of said moving object.

18. The system of claim 17, wherein said object profiling subsystem comprises a laser scanning mechanism for producing and scanning an amplitude modulated (AM) laser scanning beam across said moving object so as to collect said sequence of sample points along said moving object.

19. The system of claim 17, wherein said object profiling subsystem comprises a mechanism for producing said sequence of data sets using on or more of structured laser illumination, CCD imaging and triangulation measurement techniques.

20. The system of claim 17, wherein a plurality of linear range and intensity data maps are sequentially produced by said object profiling subsystem and a plurality of linear images are sequentially produced by said linear imaging subsystem, and wherein said image processing computer uses said plurality of linear range and intensity data maps and said plurality of linear images to produce a plurality of cropped linear images which are buffered in a 2-D memory array and then processed using image-based bar code symbol decoding and/or OCR-based image processing operators.

21. The system of claim 17, wherein said object bearing object identifying information is indicium selected from the group consisting of a bar code symbol, textual information, and graphics.

22. The system of claim 17, wherein said object is a package being transported along a conveyor belt structure.