Apparatus and method for automatically recognizing a QR code

• US 8,908,975 B2
• Filed: 10/09/2012
• Issued: 12/09/2014
• Est. Priority Date: 07/21/2011
• Status: Active Grant

• Current Assignee: Yewon Communication Company Limited
• Original Assignee: Yewon Communication Company Limited
• Inventors: Bae, So Woon, Kim, Byoung Sun, Yang, Sung Ho
• Primary Examiner(s): Rahmjoo, Mike
• Application Number:
  US14/351,142
• Publication Number:
  US 20140314320A1
• Time in Patent Office: 791 Days
• Field of Search: 382/190, 382/254, 382/233, 382/209, 382/103, 382/132, 382/243
• US Class Current: 382/190
• CPC Class Codes: G06F 18/2113 by ranking or filtering the set of features, e.g. using a measure of variance or of feature cross-correlation
• CPC Class Codes: G06K 7/10811 Focalisation
• CPC Class Codes: G06K 7/1417 2D bar codes
• CPC Class Codes: G06K 7/1443 locating of the code in an image
• CPC Class Codes: G06K 7/1465 using several successive scans of the optical code
• CPC Class Codes: G06K 7/1478 adapting the threshold for pixels in a CMOS or CCD pixel sensor for black and white recognition

Abstract

An apparatus and method for automatically recognizing a QR code without a need to control the distance for recognition in relation to one QR code or two or more QR codes. The apparatus includes a photographing unit obtaining a surrounding image the QR code including recognition points and surroundings, a QR code recognition unit converting the surrounding image into a grayscale image of a pixel unit, converting the grayscale image into a histogram indicative of a distribution map according to the luminosity of each pixel, extracting only pixels having a luminosity value concentration level corresponding to a threshold or higher based on the histogram, setting the extracted pixels as a candidate pixel group, searching the set candidate pixel group for recognition points through a recognition marker, when the recognition points are conceived, recognizing a region in which the conceived recognition points are placed as a QR code.

Claims

1. An apparatus for automatically recognizing a QR code, comprising:

a photographing unit capturing images of a QR code including recognition points and surroundings of the QR code, and obtaining a surrounding image including the QR code;

a QR code recognition unit converting the surrounding image including the QR code obtained by the photographing unit into a grayscale image of a pixel unit, converting the grayscale image into a histogram indicative of a distribution map according to luminosity of each pixel, extracting only pixels having a luminosity value concentration level the same as or higher than a threshold based on the histogram, setting extracted pixels as a candidate pixel group, searching the set candidate pixel for recognition points through a recognition marker, recognizing a region in which the recognition points are places as a QR code if the recognition points are conceived in the candidate pixel group, and reading out information stored in the recognized QR code;

a display unit for displaying an image of the recognized QR code or displaying the read-out information in the QR code; and

a memory unit for matching the image of the recognized QR code with the read-out information in the QR code and storing the matched image and the read-out information,

wherein, if three recognition points are not recognized in the candidate pixel group through the recognition marker and thus a QR code is not recognized, the QR code recognition unit enlarges the surrounding image including the QR code obtained through the photographing unit in a vector way, corrects the enlarged surrounding image, converts the enlarged and corrected surrounding image including the QR code into a grayscale image of a pixel unit, converts the grayscale image into a histogram representing a distribution map according to luminosity of each pixel, extracts only pixels each having a luminosity value concentration level the same as or higher than a threshold based on the histogram, sets the extracted pixels as a candidate pixel group, searches the set candidate pixel group for three recognition points through the recognition marker, and, if the three recognition points are conceived, recognizes a region in which the three recognition points are placed as a QR code.

2. The apparatus of claim 1, further comprising:

a communication unit externally sending an image of the recognized QR code and the read-out information in the QR code; and

a control unit controlling the image of the recognized QR code and the read-put information in the QR code so that the image and read-out information are displayed or stored, sending the image of the recognized QR code and the read-out information in the QR code through the communication unit and controlling the image of the recognized QR code and the read-out information in the QR code so that the image and the read-out information are registered with external social network service.

3. The apparatus of claim 1, wherein, if two or more QR codes are photographed through the photographing unit, the QR code recognition unit

converts a surrounding image including a QR code, first obtained by the photographing unit, into a grayscale image of a pixel unit, converts the grayscale image into a histogram indicative of a distribution map according to luminosity of each pixel, extracts only pixels each having a luminosity value concentration level corresponding to a threshold or higher based on the histogram, sets the extracted pixels as a candidate pixel group, searches the set candidate pixel group for three recognition points through a recognition marker, if the three recognition points are conceived, recognizes a region in which the three conceived recognition points are placed as a QR code, and reads out the information in the recognized QR code,

converts a surrounding image including a QR code, second obtained by the photographing unit, into a grayscale image of a pixel unit, converts the grayscale image into a histogram indicative of a distribution map according to luminosity of each pixel, extracts only pixels each having a luminosity value concentration level corresponding to a threshold or higher based on the histogram, sets the extracted pixels as a candidate pixel group, searches the set candidate pixel group for three recognition points through a recognition marker, if the three recognition points are conceived, recognizes a region in which the three conceived recognition points are placed as a QR code, and reads out the information in the recognized QR code, and

converts a surrounding image including a QR code, finally obtained by the photographing unit, into a grayscale image of a pixel unit, converts the grayscale image into a histogram indicative of a distribution map according to luminosity of each pixel, extracts only pixels each having a luminosity value concentration level corresponding to a threshold or higher based on the histogram, sets the extracted pixels as a candidate pixel group, searches the set candidate pixel group for three recognition points through a recognition marker, if the three recognition points are conceived, recognizes a region in which the three conceived recognition points are placed as a QR code, reads out the information in the recognized QR code, and displays pieces of the read-out information in the QR codes on a screen in a list form.

4. The apparatus of claim 1, further comprising:

a luminous intensity detection unit detecting luminous intensity in a periphery of the QR code; and

a flash unit lighting a flash in response to the detected luminous intensity of the luminous intensity detection unit,

wherein if surrounding luminosity is dark based on the surrounding luminous intensity detected by the luminous intensity detection unit, the flash unit lights the flash and the QR code recognition unit corrects a backlight of an image of the QR code captured by the photographing unit.

11. A computer-readable medium in which a program for executing a method for automatically recognizing a QR code according to claim 1 is recorded.

5. An application providing apparatus for a user terminal for providing a program stored on a non-transitory computer readable medium for a user terminal over a communication network, wherein the program obtains a surrounding image including a QR code by photographing the QR code including recognition points and surroundings through a camera, converts the obtained surrounding image including the QR code into a grayscale image of a pixel unit, converts the grayscale image into a histogram indicative of a distribution map according to luminosity of each pixel, extracts only pixels each having a luminosity value concentration level corresponding to a threshold or higher based on the histogram, sets the extracted pixels as a candidate pixel group, searches the set candidate pixel group for recognition points through the recognition marker, if three recognition points are conceived, recognizes a region in which the conceived three recognition points are placed as a QR code, enlarges the surrounding image including the QR code obtained through the camera in a vector way if three recognition points are not recognized in the candidate pixel group through the recognition marker and thus a QR code is not recognized, corrects the enlarged surrounding image, converts the enlarged and corrected surrounding image including the QR code into a grayscale image of a pixel unit, converts the grayscale image into a histogram indicative of a distribution map according to luminosity of each pixel, extracts only pixels each having a luminosity value concentration level corresponding to a threshold or higher based on the histogram, sets the extracted pixels as a candidate pixel group, searches the set candidate pixel group for three recognition points through the recognition marker,

if the three recognition points are conceived, recognizes a region in which the three recognition points are placed as a QR code, and reads out the information in the recognized QR code.

6. A method for automatically recognizing a QR code, comprising steps of:

(a) obtaining a surrounding image including a QR code by photographing a QR code including recognition points and surroundings through a photographing unit;

(b) converting the surrounding image including the QR code, obtained through the photographing unit, into a grayscale image of a pixel unit;

(c) converting the grayscale image into a histogram indicative of a distribution map according to luminosity of each pixel;

(d) extracting only pixels each having a luminosity value concentration level the same as or higher than a threshold based on the histogram and setting the extracted pixels as a candidate pixel group;

(e) searching the set candidate pixel group for recognition points through a recognition marker;

(f) when three recognition points are conceived in the set candidate pixel group, recognizing a region in which the conceived three recognition points are placed as a QR code; and

(g) reading out information stored in the recognized QR code,

wherein, if three recognition points are not recognized in the candidate pixel group through the recognition marker and thus a QR code is not recognized at the step (f), the surrounding image including the QR code obtained through the photographing unit is enlarged, the enlarged surrounding image is corrected, and the steps (b) to (g) are performed on the enlarged and corrected surrounding image including the QR code.

7. The method of claim 6, further comprising a step (h) of externally sending an image of the recognized QR code and the read-out information in the QR code, sending the image and the read-out information to social network service, and registering the image and the read-out information with the social network service.

8. A computer-readable medium in which a program for executing a method for automatically recognizing a QR code according to claim 7 is recorded.

9. The method of claim 6, wherein if two or more QR codes are photographed at the step (a), the steps (b) to (g) are performed on a surrounding image including a QR code that is first obtained through the photographing unit, the steps (b) to (g) are performed on a surrounding image including a QR code that is second obtained through the photographing unit, and the steps (b) to (g) are performed on a surrounding image including a QR code that is finally obtained in an identical process through the photographing unit.

10. The method of claim 9, further comprising steps of:

(h) displaying pieces of the read-out information in the QR codes on a screen in a list form;

(i) selecting one QR code from the list of pieces of information in the QR codes; and

(j) providing the read-out information for information in the QR code corresponding to the selected list.

12. A computer-readable medium in which a program for executing a method for automatically recognizing a QR code according to claim 9 is recorded.

13. The method of claim 6, wherein the step (a) comprises lighting a flash if luminous intensity in a periphery of the QR code is detected and surrounding luminosity is dark, obtaining a surrounding image including the QR code by photographing the QR code and surroundings, and correcting a backlight of the obtained surrounding image including the QR code.

14. A computer-readable medium in which a program for executing a method for automatically recognizing a QR code according to claim 13 is recorded.

15. A non-transitory computer readable medium in which a program for executing a method for automatically recognizing a QR code according to claim 6 is recorded.