Method of tracking marker and electronic device thereof

• US 9,424,651 B2
• Filed: 04/07/2015
• Issued: 08/23/2016
• Est. Priority Date: 04/07/2014
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Karciarz, Jaroslaw, Malesa, Piotr, Wojcik, Slawomir Jozef
• Primary Examiner(s): Koziol, Stephen R
• Assistant Examiner(s): SAINI, AMANDEEP SINGH
• Application Number:
  US14/680,870
• Publication Number:
  US 20150286867A1
• Time in Patent Office: 504 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30204 Marker
• CPC Class Codes: G06T 7/246 using feature-based methods, e.g. the tracking of corners or segments
• CPC Class Codes: G06V 10/245 by locating a pattern; Special marks for positioning

Abstract

Disclosed are a method and an apparatus for tracking a marker. The method of tracking a marker by an electronic device includes: detecting a position of a marker in a first frame; tracking a position of the marker in a second frame based on the position of the marker detected in the first frame; and estimating a 3D position based on the tracked position of the marker. Further, the method of tracking a marker is implemented through various embodiments.

Claims

1. A method of tracking a marker by an electronic device, the method comprising:

acquiring a previous frame of a current frame and the current frame in an image having a marker that is a pattern representing predetermined information;

detecting a position of a marker in the previous frame by detecting edges of the marker in the previous frame;

tracking a position of the marker in the current frame based on the position of the marker detected in the previous frame; and

estimating a 3D position based on the tracked position of the marker in the current frame to detect the predetermined information from the marker based on the 3D position.

2. The method of claim 1, wherein tracking the position of the marker in the current frame comprises:

identifying coordinates of edges of the marker detected in the previous frame; and

tracking the position of the marker in the current frame by using scan lines orthogonal to the edges of the markers detected in the previous frame.

3. The method of claim 2, wherein identifying the coordinates of the edges of the marker detected in the previous frame comprises:

identifying coordinates of corners of the marker detected in the previous frame;

determining lines connecting the coordinates of the edges of the marker detected in the previous frame; and

identifying coordinates of the lines.

4. The method of claim 1, wherein detecting the position of the marker in the previous frame comprises:

converting the previous frame into a binary code or gray scale; and

detecting the position of the marker based on edge detection or thresholding on the previous frame converted into the binary code or gray scale.

5. The method of claim 4, further comprising applying noise reducing to the previous frame having passed through the edge detection or thresholding.

6. The method of claim 1, wherein estimating the 3D position comprises estimating the 3D position by comparing a position of a reference marker with the detected position of the marker.

7. The method of claim 1, further comprising reducing noise by applying at least one of a Kalman filter and a particle filter to the estimated 3D position based on a position, spatial speed, rotation, and angular speed of the marker.

8. The method of claim 1, further comprising providing the estimated 3D position to a driven application program.

9. The method of claim 1, further comprising:

when the position of the marker is not detected in the previous frame, detecting a position of the marker in the current frame; and

tracking a position of a marker in a third frame based on the position of the marker detected in the current frame.

10. The method of claim 9, wherein detecting the position of the marker in the current frame comprises:

converting the current frame into a binary code or gray scale; and

detecting the position of the marker based on edge detection or thresholding on the current frame converted into the binary code or gray scale.

11. An electronic device for tracking a marker, the electronic device comprising:

a memory;

a camera; and

at least one processor configured to;

acquire a previous frame and a current frame in an image having a marker that is a pattern representing predetermined information,

detect a position of a marker in the previous frame by detecting edges of the marker in the previous frame through the camera and store the detected position of the marker in the memory,

track a position of the marker in the current frame based on the position of the marker detected in the previous frame stored in the memory, and

estimate a 3D position based on the tracked position of the marker in the current frame to detect the predetermined information from the marker based on the 3D position.

12. The electronic device of claim 11, wherein the processor is further configured to:

identify coordinates of edges of the marker detected in the previous frame stored in the memory; and

track the position of the marker in the current frame by using scan lines orthogonal to the edges of the markers detected in the previous frame.

13. The electronic device of claim 12, wherein the processor is further configured to:

identify coordinates of corners of the marker detected in the previous frame stored in the memory;

determine lines connecting the coordinates of the corners of the marker detected in the previous frame; and

identify the coordinates of the edges of the marker by using coordinates of the lines.

14. The electronic device of claim 11, wherein the processor is further configured to:

convert the previous frame into a binary code or gray scale; and

detect the position of the marker based on edge detection or thresholding on the previous frame converted into the binary code or gray scale.

15. The electronic device of claim 14, wherein the processor is further configured to apply noise reducing to the previous frame having passed through the edge detection or thresholding.

16. The electronic device of claim 11, wherein the processor is further configured to estimate the 3D position by comparing a position of a reference marker with the detected position of the marker.

17. The electronic device of claim 11, wherein the processor is further configured to reduce noise by applying at least one of a Kalman filter and a particle filter to the estimated 3D position based on a position, spatial speed, rotation, and angular speed of the marker.

18. The electronic device of claim 11, wherein the processor is further configured to provide the estimated 3D position to a driven application program.

19. The electronic device of claim 11, wherein the processor is further configured to:

when the position of the marker is not detected in the previous frame, detect a position of the marker in the current frame; and

track a position of a marker in a third frame based on the position of the marker detected in the current frame.

20. The electronic device of claim 19, wherein the processor is further configured to:

convert the current frame into a binary code or gray scale; and

detect the position of the marker based on edge detection or thresholding on the current frame converted into the binary code or gray scale.