Apparatus, system, and method of transmitting encoded image data, and recording medium storing control program

1. A communication terminal that communicates with a counterpart communication terminal through a network, the communication terminal comprising:

a processor configured to:

detect a state of the network and calculate a transmission data size that is suitable to the detected state of the network;

receive image data captured by a capturing device and analyze contents of the image data to determine an image parameter that should be prioritized;

encode the image data into encoded image data having a data size equal to or less than the calculated transmission data size by applying encoding processing that is determined based on the image parameter that should be prioritized; and

a network interface configured to transmit the encoded image data to the counterpart communication terminal through the network, wherein

the image parameter that should be prioritized is selected from a frame rate of the image data and a resolution of the image data, and

the processor applies encoding processing that keeps a sufficient level of frame rate when the frame rate is selected as the image parameter that should be prioritized, and applies encoding processing that keeps a sufficient level of resolution when the resolution is selected as the image parameter that should be prioritized.

2. The communication terminal of claim 1 , wherein the processor analyzes the contents of the image data using an image recognition method.

3. The communication terminal of claim 2 , wherein the image recognition method includes a human detection method of detecting a human object in the image data.

4. The communication terminal of claim 1 , wherein the processor is further configured to:

analyze whether capturing of a moving object in the image data is a dominant characteristic of the contents of the image data; and

determine that the frame rate is the image parameter that should be prioritized when capturing of the moving object is a dominant characteristic, and that the resolution is the image parameter that should be prioritized when capturing of the moving object is not a dominant characteristic.

5. The communication terminal of claim 1 , wherein the processor is further configured to:

count a number of moving objects in the image data; and

determine that the frame rate of the image data is the image parameter that should be prioritized when the counted number of moving objects reaches a predetermined number, and that the resolution of the image data is the image parameter that should be prioritized when the counted number of moving objects does not reach the predetermined number.

6. The communication terminal of claim 1 , wherein the processor is further configured to:

analyze whether the movement of a moving object is significant between image data that is previously analyzed by the processor and the image data that is currently analyzed by the processor; and

determine that the frame rate is the image parameter that should be prioritized when the movement of the moving object is significant, and that the resolution is the image parameter that should be prioritized when the movement of the moving object is not significant.

7. A communication system, comprising:

a first communication terminal;

a second communication terminal connected to the first communication terminal through a network; and

a server apparatus connected to the first communication terminal and the second communication terminal through the network and to relay data between the first communication terminal and the second communication terminal, wherein

the first communication terminal includes:

a network state detector configured to detect a state of the network based on network state information received from the server apparatus, and calculate a transmission data size that is suitable to the detected state of the network;

an image determiner to receive image data captured by a capturing device and analyze contents of the image data to determine an image parameter that should be prioritized;

an encoder to encode the image data into encoded image data having a data size equal to or less than the calculated transmission data size by applying encoding processing that is determined based on the image parameter that should be prioritized; and

a network interface configured to transmit the encoded image data to the server apparatus through the network, and

the second communication terminal includes:

a network interface configured to receive the encoded image data from the server apparatus through the network; and

a decoder to decode the encoded image data into decoded image data for display onto a display device, wherein

the image parameter that should be prioritized is selected from a frame rate of the image data and a resolution of the image data, and

the encoder of the first communication terminal applies encoding processing that keeps a sufficient level of frame rate when the frame rate is selected as the image parameter that should be prioritized, and applies encoding processing that keeps a sufficient level of resolution when the resolution is selected as the image parameter that should be prioritized.

8. The communication system of claim 7 , wherein the image determiner of the first communication terminal is further configured to:

analyze whether capturing of a moving object in the image data is a dominant characteristic of the contents of the image data; and

determine that the frame rate is the image parameter that should be prioritized when capturing of the moving object is a dominant characteristic, and that the resolution is the image parameter that should be prioritized when capturing of the moving object is not a dominant characteristic.

9. A method of communicating image data with a counterpart communication terminal through a network, the method comprising:

detecting a state of the network;

calculating a transmission data size that is suitable to the detected state of the network;

receiving image data captured by a capturing device;

analyzing contents of the image data to determine an image parameter that should be prioritized;

encoding the image data into encoded image data having a data size equal to or less than the calculated transmission data size by applying encoding processing that is determined based on the image parameter that should be prioritized; and

transmitting the encoded image data to the counterpart communication terminal through the network, wherein

the method further comprises

selecting the image parameter that should be prioritized from a frame rate of the image data and a resolution of the image data; and

applying encoding processing that keeps a sufficient level of frame rate when the frame rate is selected as the image parameter that should be prioritized; and

applying encoding processing that keeps a sufficient level of resolution when the resolution is selected as the image parameter that should be prioritized.

10. The method of claim 9 , wherein the detecting a state of the network comprises:

receiving network state information indicating the state of the network from a server apparatus through the network.

11. The method of claim 9 , further comprising:

analyzing whether capturing of a moving object in the image data is a dominant characteristic of the contents of the image data; and

determining that the frame rate is the image parameter that should be prioritized when capturing of the moving object is a dominant characteristic, and that the resolution is the image parameter that should be prioritized when capturing of the moving object is not a dominant characteristic.