Terminal for providing video call service

1. An application stored in a non-transitory computer-readable storage medium to perform a method of providing a video call service, the method comprising:

in a first terminal,

establishing a video call session between a first terminal of a first user and a second terminal of a second user;

detecting a facial expression of the first user from a first video stream that captures the first user;

generating icon information corresponding to the detected facial expression of the first user;

transmitting the generated icon information to the second terminal, and

receiving, from a server providing the video call service, virtual property information usable for the video call service, as a response to transmission of icon information of the first user acquired by the first user to the server.

2. The application of claim 1 , wherein the method further comprises receiving, from the second terminal, icon information corresponding to a facial expression of the second user detected from a second video stream that captures the second user;

wherein the receiving of the virtual property information comprises receiving, from the server, the virtual property information, as the response to the transmission of the icon information of the first user including the received icon information to the server.

3. The application of claim 1 , wherein the receiving of the virtual property information as the response to the transmission of the icon information of the first user including the transmitted icon information to the server.

4. The application of claim 1 , wherein the method further comprises:

receiving, from the second terminal, icon information corresponding to a facial expression of the second user detected from a second video stream that captures the second user; and

when the received icon information and the transmitted icon information are the same, updating the icon information of the first user.

5. The application of claim 1 , wherein the method further comprises detecting a facial expression of the second user from a second video stream that captures the second user and is received from the second terminal, and

wherein, in the generating of the icon information, when the detected facial expression of the first user and the detected facial expression of the second user are the same, icon information corresponding to the detected facial expression of the first user is generated.

6. The application of claim 1 , wherein the method further comprises:

detecting predetermined voice from voice of the first user; and

when the detected facial expression of the first user and the detected predetermined voice are matched with each other, updating the icon information of the first user.

7. The application of claim 1 , wherein the detecting facial expression of the first user comprises recognizing intensity of the facial expression by comparing a threshold value with a value corresponding to a distance difference between feature points corresponding to each other in no facial expression of the first user and the detected facial expression of the first user, and

wherein the generating of the icon information comprises updating icon information corresponding to the detected facial expression of the first user based on the recognized intensity of the facial expression.

8. The application of claim 1 , wherein the method further comprises:

displaying mission icon information on a screen of the first terminal; and

when the generated icon information and displayed mission icon information are the same, updating the icon information of the first user.

9. A application stored in a computer-readable storage medium to perform a method of providing a video call service, the method comprising:

in a first terminal,

establishing a video call session between a first terminal of a first user and a second terminal of a second user who is a counterpart in a video call;

detecting a facial expression of the second user from a second video stream that captures the second user and is received from the second terminal;

generating icon information corresponding to the detected facial expression of the second user; and

displaying the generated icon information on a screen of the first terminal, and

receiving, from a server providing the video call service, virtual property information usable for the video call service, as a response to transmission of icon information of the first user acquired by the first user to the server.

10. The application of claim 9 , wherein the receiving virtual property information comprises receiving, from the server, the virtual property information, as the response to the transmission of the icon information of the first user including the displayed icon information to the server.

11. The application of claim 9 , wherein the method further comprises detecting a facial expression of the first user from a first video stream that captures the first user, and

wherein, in the generating of the icon information, when the detected facial expression of the second user and the detected facial expression of the first user are the same, icon information corresponding to the detected facial expression of the second user is generated.

12. The application of claim 9 , wherein the method further comprises:

detecting predetermined voice from voice of the first user; and

when the detected facial expression of the second user and the detected predetermined voice are matched with each other, updating the icon information of the first user.

13. The application of claim 9 , wherein the detecting of the facial expression of the second user comprises recognizing intensity of the facial expression by comparing a threshold value with a value corresponding to a distance difference between feature points corresponding to each other in no facial expression of the second user and the detected facial expression of the second user, and

wherein the generating of the icon information comprises updating icon information corresponding to the detected facial expression of the second user based on the recognized intensity of the facial expression.

14. A non-transitory computer-readable storage medium storing instructions that are executable by a processor, the instructions comprising:

instructions to establish a video call session between a first terminal of a first user and a second terminal of a second user;

instructions to detect a facial expression of the first user from a first video stream that captures the first user;

instructions to generate icon information corresponding to the detected facial expression of the first user;

instructions to transmit the generated icon information to the second terminal; and

instructions to receive, from a server providing the video call service, virtual property information usable for the video call service, as a response to transmission of icon information of the first user acquired by the first user to the server.

15. A non-transitory computer-readable storage medium storing instructions that are executable by a processor, the instructions comprising:

instructions to establish a video call session between a first terminal of a first user and a second terminal of a second user who is a counterpart in a video call;

instructions to detect a facial expression of the second user from a second video stream that captures the second user and is received from the external terminal;

instructions to generate icon information corresponding to the detected facial expression of the second user;

instructions to display the generated icon information on a screen of the terminal; and

instructions to receive, from a server providing the video call service, virtual property information usable for the video call service, as a response to transmission of icon information of the first user acquired by the first user to the server.