# US 7,412,089 B2 · Efficient finder patterns and methods for application to 2D machine vision problems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,412,089 B2 - Document ID: US7412089B2 - Status: Granted - Kind: B2 - Application number: 11/438,687 - Filed: 2006-05-23 - Published: 2006-11-30 - Granted: 2008-08-12 - Earliest claimed: 2005-05-23 - Assignees: Nextcode Corporation - Inventors: Sanford R. Squires; James K. Levinger - Web page: https://patentgrep.com/patent/US7412089B2 ## CPC - G06K 19/06028: {using bar codes} - G06K 7/1443: {locating of the code in an image} - G06K 19/06037: {multi-dimensional coding} - G06K 19/06131: {the marking comprising a target pattern, e.g. for indicating the center of the bar code or for helping a bar code reader to properly orient the scanner or to retrieve the bar code inside of an image} - G06V 10/245: {by locating a pattern; Special marks for positioning} - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING ## Abstract The invention relates to a finder pattern for detection and location of at least one target feature in a target object. The finder pattern includes at least two triads arranged in predetermined locations in the target object, wherein each triad includes a first blob, a second blob, and a third blob, wherein each blob has substantially the same area and is positioned in a predetermined location in the target object. The locations of the first and second blobs are substantially equidistant from the third blob, and the locations of the first, second, and third blobs are not collinear. The invention further relates to a method for detecting a finder pattern in a target object, and a computer readable medium having instructions stored therein for detecting a finder pattern in a target object, which, when executed by a processor of a computing device, cause the computing device to carry out the steps of the method. ## Claims ### Claim 1 A method for detecting a finder pattern in a target object, the method comprising the steps of: processing an image of a target object; identifying six or more blobs in the image; identifying two or more potential triads in the image using the six or more identified blobs; determining information about one or more characteristics of the two or more potential triads; and determining whether the information about the characteristics of two or more of the potential triads corresponds to information about one or more characteristics of two or more target triads in a finder pattern specification, wherein the finder pattern specification includes information about the characteristics of the two or more target triads. ### Claim 2 (depends on 1) The method of claim 1, wherein the information about the characteristics of the two or more target triads in the finder pattern specification includes at least one of positional information about the target triads and information about the visual characteristics of the target triads. ### Claim 3 (depends on 1) The method of claim 1, wherein the information about the characteristics of the two or more potential triads in the finder pattern specification includes at least one of positional information about the potential triads and information about the visual characteristics of the potential triads. ### Claim 4 (depends on 1) The method of claim 1, further comprising a step of sensing the target object prior to the step of processing the image, wherein the step of sensing comprises reading the target object with a sensor. ### Claim 5 (depends on 4) The method of claim 4, wherein the sensor is selected from the group consisting of a scanner, a camera, and a range finder. ### Claim 6 (depends on 1) The method of claim 1, further comprising a step of generating a list of attributes of at least one of the potential triads by performing at least one of a binarization technique, a flat fielding technique, a creation of contour boundaries technique, or an edge detection and linking of edge boundaries around blobs technique. ### Claim 7 (depends on 1) The method of claim 1, further comprising the step of reducing the image noise with a noise reduction filter prior to the step of identifying the six or more blobs in the image. ### Claim 8 (depends on 1) The method of claim 1, further comprising the step of eliminating blobs having one or more attributes that do not meet a predetermined criterion prior to the step of identifying the two or more potential triads. ### Claim 9 (depends on 1) The method of claim 1, further comprising the step of processing the finder pattern specification using a computing device prior to the step of determining whether the information about the characteristics of two or more of the potential triads corresponds to information about one or more characteristics of two or more target triads in the finder pattern specification. ### Claim 10 A computer readable medium having instructions stored therein for detecting a finder pattern in a target object, which, when executed by a processor of a computing device, cause the computing device to carry out the steps of: processing an image of a target object; identifying six or more blobs in the image; identifying two or more potential triads in the image using the six or more identified blobs; determining information about one or more characteristics of the two or more potential triads; and determining whether the information about the characteristics of two or more of the potential triads corresponds to information about one or more characteristics of two or more target triads in a finder pattern specification, wherein the finder pattern specification includes information about the characteristics of the two or more target triads. ### Claim 11 (depends on 10) The computer readable medium of claim 10, wherein the information about the characteristics of the two or more target triads in the finder pattern specification includes at least one of positional information about the target triads and information about the visual characteristics of the target triads. ### Claim 12 (depends on 10) The computer readable medium of claim 10, wherein the information about the characteristics of the two or more potential triads in the finder pattern specification includes at least one of positional information about the potential triads and information about the visual characteristics of the potential triads. ### Claim 13 (depends on 10) The computer readable medium of claim 10, further comprising instructions for sensing the target object prior to the step of processing the image, wherein the step of sensing comprises reading the target object with a sensor. ### Claim 14 (depends on 13) The computer readable medium of claim 13, wherein the sensor is selected from the group consisting of a scanner, a camera, and a range finder. ### Claim 15 (depends on 10) The computer readable medium of claim 10, further comprising instructions for generating a list of attributes of at least one of the potential triads by performing at least one of a binarization technique, a flat fielding technique, a creation of contour boundaries technique, or an edge detection and linking of edge boundaries around blobs technique. ### Claim 16 (depends on 10) The computer readable medium of claim 10, further comprising instructions for reducing the image noise with a noise reduction filter prior to the step of identifying the six or more blobs in the image. ### Claim 17 (depends on 10) The computer readable medium of claim 10, further comprising instructions for eliminating blobs having one or more attributes that do not meet a predetermined criterion prior to the step of identifying the two or more potential triads. ### Claim 18 (depends on 10) The computer readable medium of claim 10, further comprising instructions for processing the finder pattern specification using a computing device prior to the step of determining whether the information about the characteristics of two or more of the potential triads corresponds to information about one or more characteristics of two or more target triads in the finder pattern specification.