Mobile device tracking

• US 7,681,796 B2
• Filed: 01/05/2006
• Issued: 03/23/2010
• Est. Priority Date: 01/05/2006
• Status: Expired due to Fees

• Current Assignee: Toshiba Global Commerce Solutions Holdings Corporation (Toshiba Corporation)
• Original Assignee: International Business Machines Corporation
• Inventors: Zimmerman, Thomas Guthrie, Cato, Robert Thomas
• Primary Examiner(s): Koyama; Kumiko C
• Assistant Examiner(s): Johnson; Sonji
• Application Number:
  US11/325,952
• Publication Number:
  US 20070152057A1
• Time in Patent Office: 1,538 Days
• Field of Search: 250/559.22, 348/501, 382/291, 235/462.16, 235/462.08
• US Class Current: 235/462.08
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/74 Systems using reradiation of electromagnetic waves other than radio waves, e.g. IFF, i.e. identification of friend or foe
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/0244 using reflecting strips
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means

Abstract

The present invention provides a method, apparatus, and computer program product for obtaining the location of, for example, a mobile device. An image of a target in a defined space is obtained, the target encoding data from which its location in the defined space may be determined. The position of a reference point in the image which represents the location of, for example, a mobile device, is determined relative to the target. The location of the mobile device in the defined paces is then determined by combining the location of the target in the defined space with an appropriately scaled version of the relative position of the reference point to the target in the image.

Claims

1. A method for determining a location of a second linear barcode within a defined space given a location of a first linear barcode within the defined space, the method comprising:

obtaining an image encompassing the first linear barcode and the second linear barcode;

determining pixel lengths by measuring within the image a vertical pixel distance and a horizontal pixel distance between the first linear barcode and the second linear barcode; and

multiplying the pixel lengths by a scaling factor to obtain the location of the second linear barcode, the scaling factor relating dimensions of the image to dimensions of the defined space.

2. A method for determining the accuracy of known locations of a first linear barcode and a second linear barcode within a defined space, the method comprising:

obtaining an image encompassing the first linear barcode and the second linear barcode;

determining pixel lengths by measuring within the image a vertical pixel distance and a horizontal pixel distance between the first linear barcode and the second linear barcode;

multiplying the pixel lengths by a scaling factor to obtain a calculated location of the second linear barcode, the scaling factor relating dimensions of the image to dimensions of the defined space; and

comparing the calculated location of the second linear barcode with the known location of the second linear barcode.