Endoscope system and control method thereof

1. A control method of an endoscope system comprising:

acquiring a plurality of omnidirectional images of surroundings of an endoscope using a stereo omnidirectional camera mounted on the endoscope;

calculating distances between the endoscope and an object around the endoscope using the acquired plurality of omnidirectional images; and

executing an operation to avoid collision between the endoscope and the object around the endoscope based on the calculated distances;

wherein the executing an operation includes providing information regarding a moving direction of the endoscope to avoid collision between the endoscope and the object around the endoscope for moving the endoscope to a central region of the object around the endoscope; and

constructing a 3D grid map of the object around the endoscope based on the calculated distances,

wherein the constructing includes,

forming a plurality of 3D grids by dividing the object around the endoscope according to a desired angle and a desired distance, and

determining distance information representing each of the plurality of 3D grids.

2. The control method according to claim 1 , wherein the calculating distances includes,

executing stereo matching of the acquired plurality of omnidirectional images, and

calculating the distances based on information calculated from a disparity map acquired as a result of the stereo matching.

3. The control method according to claim 2 , wherein the executing stereo matching includes,

converting the acquired plurality of omnidirectional images into a plurality of panoramic images,

extracting feature points from the converted plurality of panoramic images, and

acquiring the disparity map of the plurality of panoramic images using a sum of absolute differences (SAD) algorithm.

4. The control method according to claim 1 , wherein, in the executing an operation, the information regarding the moving direction of the endoscope is provided so as to move the endoscope in a direction that increases a shortest distance from among the calculated distances between the endoscope and the object around the endoscope.

5. The control method according to claim 1 , wherein, in the executing an operation, the information regarding the moving direction of the endoscope is provided so as to move the endoscope in a direction toward a center of gravity of a cross-section of the object around the endoscope.

6. The control method according to claim 1 , wherein the executing an operation includes transmitting force and motion to an operating unit that is configured to operate the moving direction of the endoscope using force feedback of haptics.

7. The control method according to claim 1 , wherein the distance information representing each of the plurality of 3D grids is a mean distance of points forming each of the plurality of 3D grids.

8. An endoscope system comprising:

an endoscope including a stereo omnidirectional camera configured to acquire a plurality of omnidirectional images of the surroundings of the endoscope; and

at least one processor configured to,

calculate distances between the endoscope and an object around the endoscope using the acquired plurality of omnidirectional images, and

execute an operation to avoid collision between the endoscope and the object around the endoscope based on the calculated distances;

generate a control signal to provide information regarding a moving direction of the endoscope to avoid collision between the endoscope and the object around the endoscope, and

move the endoscope to a central region of the object around the endoscope, and

construct a 3D grid map of the object around the endoscope based on the calculated distances,

form a plurality of 3D grids by dividing the object around the endoscope according to a desired angle and a desired length, and

determine distance information representing each of the plurality of 3D grids.

9. The endoscope system according to claim 8 , wherein the at least one processor is further configured to,

execute stereo matching of the acquired plurality of omnidirectional images; and

calculate the distances between the endoscope and the object around the endoscope based on information calculated from a disparity map acquired as a result of the stereo matching.

10. The endoscope system according to claim 9 , wherein the at least one processor is further configured to,

convert the acquired plurality of omnidirectional images into a plurality of panoramic images,

extract feature points from the converted plurality of panoramic images, and

acquire the disparity map of the plurality of panoramic images using a sum of absolute differences (SAD) algorithm.

11. The endoscope system according to claim 9 , wherein the at least one processor is configured to generate the control signal to provide the information regarding the moving direction of the endoscope so as to move the endoscope in a direction that increases a shortest distance from among the calculated distances between the endoscope and the object around the endoscope.

12. The endoscope system according to claim 8 , wherein the at least one processor is further configured to generate the control signal to provide the information regarding the moving direction of the endoscope so as to move the endoscope in a direction toward a center of gravity of a cross-section of the object around the endoscope.

13. The endoscope system according to claim 8 , wherein the at least one processor is further configured to generate a control signal to transmit force and motion to an operating unit that is configured to operate the moving direction of the endoscope using force feedback of haptics.

14. The endoscope system according to claim 8 , wherein the at least one processor is further configured to determine a mean distance of points forming each of the plurality of 3D grids as the distance information representing each of the plurality of 3D grids.