KR100976361B1 - Method for automatically changing mobile telecommunication call mode between video phone call and voice phone call - Google Patents

Abstract

The present invention relates to a technology for automatically switching a mobile communication call mode between a video call and a voice call, and in particular, by measuring the brightness of an image detected by a video camera mounted on a terminal to determine a call operation of a terminal user. The present invention relates to a mobile communication call mode automatic switching technology capable of automatically switching to a voice call mode or automatically returning to a video call mode. According to the present invention, a user who is conducting a video call with the other party through a mobile communication terminal supporting a video call can automatically switch the call mode to the voice call mode by simply bringing the terminal near the ear. In addition, if it is necessary to make a video call after finishing a voice call, the call mode returns to the video call mode only by bringing the terminal back to the eyes, so that the user can easily switch the call mode with a simple operation of the user.

Video Call, Voice Call, Call Mode, Camera, Auto Switch, 3G Phone

Description

How to automatically switch mobile communication mode between video call and voice call {METHOD FOR AUTOMATICALLY CHANGING MOBILE TELECOMMUNICATION CALL MODE BETWEEN VIDEO PHONE CALL AND VOICE PHONE CALL}

The present invention relates to a technology for automatically switching a mobile communication call mode between a video call and a voice call, and in particular, by measuring the brightness of an image detected by a video camera mounted on a terminal to determine a call operation of a terminal user. The present invention relates to a mobile communication call mode automatic switching technology capable of automatically switching to a voice call mode or automatically returning to a video call mode.

Recently released 3G phones (3-generation phones), unlike the existing 2G phones that only support voice calls support video calls that callers can see each other's video call. That is, the image of the caller is captured by an image camera mounted on the terminal, and an image is generated. In order to transmit both video and audio, a mobile communication signal is transmitted through a mobile communication network of a new frequency band capable of supporting video calls without using a mobile communication network of a conventional frequency band.

However, the 3G phone supporting the video call includes a voice call service function that can use the frequency band used in the conventional voice call. Therefore, the 3G phone user can call the other party through the voice call method as in the past without using a video call. In general, a 3G phone is provided with a video call button, so when the user presses the video call button, the video camera operates and can make a video call.

As such, 3G phone users who support video calls, which are more advanced technologies than conventional voice calls, use voice calls instead of video calls for many reasons.

The first reason to use a voice call instead of a video call is that using a video call is more expensive than a voice call. In addition, there is a problem that the battery of the terminal wears out quickly, there is a problem that both parties to the call must have a 3G phone. In addition, callers tend to prefer voice calls because of the burden of showing themselves as they are.

Therefore, even a terminal user who supports a video call actually has many users who want to make a call in the voice call mode, and in some cases, many users want to have both a video call and a voice call in parallel.

In other words, even if a video call is required due to the exchange of visual information, most of the calls are usually made through voice calls, or during the voice call, the other party checks the other party or checks the memo or video information. In order to exchange, voice calls and video calls frequently need to be used alternately.

As such, it is possible to anticipate the necessity of alternately using a voice call and a video call through a video call supporting terminal. However, whenever a user changes the call mode, the user manually switches the call mode by operating a terminal key. There is a problem that is very troublesome and disturbs the flow of natural calls.

An object of the present invention is to use a mobile communication terminal that supports a video call without having to manually set the call mode switching between the video call mode and the voice call mode mobile communication call mode is automatically switched only by the user's call operation It is to provide automatic switching technology.

In a method of automatically switching a call mode between a video call and a voice call according to an embodiment of the present invention, in a method of supporting a video call and a voice call in a video call terminal, (A) capturing an external video of the terminal to capture a video call image. Generating; (B) determining the brightness of the video call image; (C) changing the video call mode to the voice call mode if the brightness of the video call image is equal to or less than a first predetermined reference value; (D) setting a video call terminal to transmit / receive video call data including video call images and voice data if the current call mode is a video call mode; And (E) setting the video call terminal to transmit / receive voice data when the current call mode is a voice call mode.

Also, in the method of automatically switching the call mode between the video call and the voice call according to an embodiment of the present invention, step (B) includes Bayer RGB values consisting of R (red), G (green), and B (blue) values through a video camera. Generating a video call image in a format; And calculating brightness of the video call image from each of the R, G, and B values constituting the video call image.

Also, in the method for automatically switching the call mode between the video call and the voice call according to an embodiment of the present invention, step (B) is performed by using a YUV format including Y (brightness information), U, and V (color information) values through a video camera. Generating a video call image; And calculating the brightness of the video call image from the Y value constituting the video call image.

Also, in the method for automatically switching the call mode between the video call and the voice call according to the embodiment of the present invention, if the current call mode is the voice call mode, the method is changed from the video call mode to the voice call mode through step (C). Determining; And when the determination result is changed from the video call mode to the current voice call mode, returning the current call mode to the video call mode when the brightness of the video call image changes to a preset second reference value or more. It is preferable.

Also, in the method for automatically switching the call mode between the video call and the voice call according to an embodiment of the present invention, the step (C) may include (C-1) determining whether the current call mode is the video call mode; (C-2) if the current call mode is a video call mode, determining whether the brightness of the video call image falls below a first reference value; (C-3) if the brightness of the video call image falls below the first reference value, determining whether the brightness of the video call image is kept below the first reference value for more than a preset reference time; And (C-4) changing the video call mode to the voice call mode if the brightness of the video call image is kept below the first reference value for more than a reference time.

In addition, the method for automatically switching the call mode between the video call and the voice call according to an embodiment of the present invention, when the first reference value learning setting command is input by the user's operation, drives the image camera of the mobile communication terminal, and the external image of the terminal. And a first reference value learning setting step of generating a video call image by capturing the image, and statistically processing the brightness distribution of the video call image to set the first reference value.

According to the present invention, a user who is conducting a video call with the other party through a mobile communication terminal supporting a video call can automatically switch the call mode to the voice call mode by simply bringing the terminal near the ear. In addition, if it is necessary to make a video call after finishing a voice call, the call mode returns to the video call mode only by bringing the terminal back to the eyes, so that the user can easily switch the call mode with a simple operation of the user.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram illustrating the overall concept of a technology for automatically switching a call mode between a video call and a voice call according to the present invention.

The mobile communication terminal according to the implementation of the present invention is a terminal supporting both video and voice calls, but the user can manually select a call mode, but can also automatically switch the call mode according to the present invention.

In the video call mode shown in FIG. 1 (A), an image of a user is photographed using an image camera mounted on a mobile communication terminal and then transmitted to a counterpart terminal. In this case, in order to capture the image of the user, it is necessary to keep the user's face in the field of view of the camera at a distance from the terminal.

In the video call mode, the microphone and speaker of the terminal are far from the user, so parts with good sensitivity must be used to transmit the voice signal well, and a separate device such as an earphone or an external microphone may be installed to compensate for this. .

1 (B) shows a voice call mode. Unlike in the video call mode, in the voice call mode, there is no need to photograph the user's image, so the microphone and the speaker of the terminal are used in close contact with the user's face as in a general telephone. In the present invention, when the terminal is in close contact with the user's face, the distance between the part where the image camera is located and the user's face is closer, and thus the amount of light coming from the outside is reduced and the captured image is darkened.

That is, when the user calls in the video call mode, the user does not need to send a video, and when the user brings the terminal to the ear, the terminal automatically recognizes it and switches the call mode to the voice call mode.

In general, in the voice call mode, a video call is made without a video camera. However, in the present invention, even when the video call mode is switched from the video call mode to the voice call mode, the video camera of the terminal is still operated. Stays in the state.

Therefore, if the user who has switched the video call mode from the video call mode to the voice call mode and takes the call away from the terminal again, the call mode returns to the original video call mode.

2 is a flowchart illustrating the overall operation of a method for automatically switching a call mode between a video call and a voice call according to the present invention.

The user may use the mobile communication terminal in a video call mode or a voice call mode according to a selection. In general, when the user sets the terminal to the voice call mode, the image camera mounted on the terminal is set not to operate. Therefore, even if the user makes a call in the voice call mode and puts the terminal away for a while, it is preferable that the call mode is not switched to the video call mode.

However, if the user has set the terminal to the video call mode from the beginning (ST10).

First, an external image of the terminal is captured by using an image camera mounted on the mobile communication terminal, and a video call image is generated through this (ST20). In this case, the image camera may be provided with an image sensor of Bayer RGB format, or may be provided with an image sensor of YUV format.

Bayer RGB format image sensors are composed of R (red), G (green), and B (blue) pixels. In general, G pixels are twice as large as R and B pixels. Bayer RGB format has only one color information per pixel and then generates an image by estimating the value of adjacent pixels through interpolation process. However, in the present invention, only the brightness of the external image needs to be measured in order to switch the call mode, and thus Bayer RGB values may be directly used without going through interpolation.

The YUV format image sensor is composed of Y (brightness information), U (color information), and V (color information) pixels, and U and V are also denoted by Cb and Cr, respectively. U represents the deviation from the B (blue) value and V represents the deviation from the R (red) value.

Next, the brightness of the video call image is determined (ST30).

When the image camera generates the Bayer RGB format image, the closer to 0, the darker the color is. Therefore, the brightness of the video call image is calculated in consideration of each of R, G, and B values.

However, when the YUV format image is generated by the image camera, since the brightness information is included only in the Y value, the closer the Y value is to 0, the darker color is recognized. Therefore, the brightness of the video call image is calculated from the Y value.

Also, in case of Bayer RGB format, each value of R, G, and B may be considered separately, but after calculating Y value using the formula that converts RGB value into YUV value, brightness of video call image is calculated using Y value only. You may. Keith Jack's formula and Julien's formula are widely known as a method of converting RGB values to YUV values.

After determining the brightness of the video call image, if the brightness of the video call image is equal to or less than the first predetermined reference value (ST40), the terminal user assumes that the terminal is brought near the user's ear, and the current video call mode is changed to the voice call mode. Change (ST50). However, if the brightness of the video call image is equal to or greater than the first reference value, the user assumes that the video call is still in progress and maintains the current video call mode (ST70). In this case, the process of changing from the video call mode to the voice call mode in consideration of a more realistic situation will be described in detail later with reference to FIG. 3.

Here, the first reference value refers to a reference value for switching the video call mode to the voice call mode, and the image of the video call image when the surface of the image camera of the terminal starts to be covered by a lot of other objects and the amount of light passing through is very reduced. Can be interpreted as brightness. The first reference value may be set in advance from the time of release of the terminal, or the first reference value may be reset by the user setting method described with reference to FIG. 4.

Through the above process, the video call mode may be switched to the voice call mode or the video call mode may be maintained. Alternatively, the voice call mode may be maintained while the image camera is not operated from the beginning. The processing of the mobile communication signal according to the state of the current call mode is as follows.

If the current call mode is the voice call mode, the video call terminal is set to transmit and receive voice data (ST60). That is, the movement of the terminal is set such that audio data is compressed through a vocoder or the like suitable for processing human voice in a low frequency band and exchanged a mobile communication signal through a mobile communication network in a frequency band supporting voice call. Set the communication environment to an environment in which voice data can be transmitted. In addition, a voice call is made with the other party through the mobile communication environment.

However, if the current call mode is the video call mode, the video call terminal is set to transmit and receive video call data including video call images and voice data (ST80). That is, since not only the voice data input through the microphone of the terminal but also the video call data input through the video camera must be transmitted together, the mobile communication environment of the terminal is set up so that the call is made through the mobile communication network of the frequency band supporting the video call. do. Therefore, the multimedia data including both voice data and video call data is compressed through a multimedia codec such as MPEG, AVI, H.264, and then the mobile communication signal is transmitted and received through a mobile communication network of a multimedia frequency band supporting video call. . When receiving data from the other party's terminal, it decodes it through a multimedia codec, separates it into an audio signal and a video signal, and outputs it through a speaker and a screen, respectively, thereby making a video call with the other party.

Through the above process, the video communication mode is automatically switched to the voice call mode by detecting a call operation of the user in the mobile communication terminal. In this case, the process of continuously detecting the user's call operation may be added to return to the video call mode from the voice call mode, and the process of returning from the voice call mode to the video call mode will be described in detail later with reference to FIG. 5. do.

FIG. 3 is a flowchart illustrating an operation process of changing the video call mode to the voice call mode in FIG. 2 (ST40 and ST50) in more detail.

First, it is determined whether the current call mode is the video call mode (ST41). If the voice call mode is not the video call mode, the voice call mode is maintained (ST50).

However, if the current call mode is the video call mode, it is determined whether the brightness of the video call image coming through the video camera falls below the first reference value while continuing the signal processing according to the video call (ST42). In this case, the first reference value refers to a reference value for switching the video call mode to the voice call mode as described above with reference to FIG. 2.

As a result of the determination, when the brightness of the video call image falls below the first reference value, it is determined whether the brightness of the video call image is kept below the first reference value for a predetermined reference time T or more (ST43). If the brightness of the video call image is maintained below the first reference value for more than the reference time T, the video call mode is changed to the voice call mode (ST50). That is, even if the condition for changing the video call mode to the voice call mode is satisfied, the state of the state is maintained for a certain period of time after the transition of the call mode has the effect of switching.

For example, while a user is in a video call, the video camera may be blocked for various reasons, and the ambient light may be momentarily dim. Therefore, the brightness of the video call image may become dark regardless of the user's intention, so that in this case, the reference time for switching the video call mode to the voice call mode may be set to prevent the call mode from being automatically switched. Configured.

At this time, the reference time (T) can be set a variety of times according to the user's selection. That is, it is possible to set the appropriate time according to the user's behavior pattern. If the reference time is set to 0, the call mode is changed to the voice call mode as soon as the brightness of the video call image falls below the first reference value.

FIG. 4 is a flowchart illustrating an operation process of a first reference learning setup step added to FIG. 2.

The first reference value, which is a reference value for automatically switching the call mode from the video call mode to the voice call mode, may be preset at the time of terminal release or may be set through key operation of the terminal.

However, if the first reference value is set through learning by analyzing the behavior pattern of the terminal user, the first reference value may be more optimal. That is, the first reference value is appropriately calculated by detecting in advance the extent to which the brightness of the image generated by the image camera changes when the user uses the terminal to the ear.

First, when the first reference value learning setting command is input by the user's operation (ST1), the image camera of the mobile communication terminal is driven (ST2). This can be done at any time during a video call or a voice call, and even during a voice call, when the first reference value learning setting command is input, the image camera is driven to prepare for setting the first reference value.

Next, an external video of the terminal is captured to generate a video call image (ST3).

The brightness of the video call image is determined (ST4) and the brightness distribution of the video call image is statistically processed (ST5). That is, the user can grasp the brightness near the video camera in an environment where the terminal becomes dark as in a voice call by setting the terminal to the first reference learning setting state and bringing the terminal to the ear. By statistically processing the distribution gradually changing for each time period, the average value of the external brightness may be calculated and reflected in setting the first reference value.

In addition, since the brightness of the video call image changes rapidly and the holding time is short while the user is holding the terminal to the ear, such data is treated as meaningless data to set the maximum and minimum values of the first reference value within the meaningful data. The first reference value may be set by performing statistical processing on the brightness of the video call image.

That is, the first reference value, which is a reference value for switching the voice call mode to the video call mode, is set by reflecting the statistical processing result (ST6).

FIG. 5 is a flowchart illustrating an operation of returning to a video call mode from a voice call mode added to FIG. 2.

The process of switching from the voice call mode to the video call mode occurs when the external environment of the terminal becomes bright due to the terminal user taking the terminal away from the ear. At this time, it is not preferable that the call mode is automatically switched to the video call mode when the user puts down the terminal for a while in a general voice call. In addition, since most mobile communication users still use the voice call from the beginning instead of the video call during the call, it is desirable to maintain the voice call in this case.

Therefore, it is preferable that the voice call mode is automatically switched to the video call mode only when the user first switches to the voice call mode due to the positional movement of the terminal while using the video call mode. In this case, the process of returning the voice call mode to the video call mode by brightening the surrounding environment is as follows.

First, it is determined whether the current call mode is the voice call mode (ST90). If it is determined that the video call mode is not the voice call mode, the video call state is maintained.

However, if the current call mode is the voice call mode, it is determined whether the current voice call mode is changed to the voice call mode through an automatic switching process through the video call mode (ST100).

If it is determined that the video call mode is not converted to the voice call mode through automatic switching, the current voice call mode is maintained since the normal voice call mode (ST140).

However, if the current voice call mode has been converted from the video call mode through automatic switching, it is determined whether the brightness of the video call image captured by the image camera is changed to be greater than or equal to the second preset value (ST110).

As a result, when the brightness of the video call image is changed to the second reference value or more, the user of the mobile communication terminal makes a voice call, and then removes the terminal from the ear near the ear for a video call, and then brings the current call mode to the video call. Return to the mode (ST120). However, if the brightness of the video call image is less than or equal to the second reference value, the user assumes that the voice call is still in progress and maintains the current voice call mode (ST140).

Here, the second reference value means a reference value for switching the voice call mode to the video call mode, and may consider the case opposite to the first reference value. In reality, the second reference value and the first reference value may be set to the same value, but in some cases, the second reference value and the first reference value may be set differently so that the switching of the call mode may be more smoothly performed.

When the call mode is set to the video call mode or the voice call mode through the above process, the mobile communication signal is processed according to each case.

That is, if the current call mode is a video call mode, the video call terminal is set to transmit and receive video call data including video call images and audio data (ST150), and the current call mode is the video call mode. In this case, the video call terminal is set to transmit and receive voice data to perform a voice call with the counterpart terminal (ST130). The specific signal processing process at this time is the same as described above in the mobile communication signal processing processes ST60 and ST80 of FIG. 2.

In this case, in the process of returning to the video call mode by applying the second reference value, the reference time may be set by applying the case of the first reference value described above with reference to FIG. 3, and the method of setting the second reference value may also be described with reference to FIG. 4. The user can set learning by applying the first reference value as it is.

Through the above process, the user who has been making the call in the voice call mode can return to the video call mode by changing the call operation and talk to the other party while watching the screen of the terminal.

Although the present invention has been described in more detail with reference to the examples, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is an exemplary view showing the overall concept of the automatic mode switching technology between video call and voice call according to the present invention,

2 is a flowchart illustrating the overall operation of the method for automatically switching the call mode between the video call and the voice call according to the present invention;

3 is a flowchart illustrating in more detail an operation process of changing the video call mode to the voice call mode in FIG. 2 (ST40 and ST50);

4 is a flowchart illustrating an operation process of a first reference learning setup step added to FIG. 2;

FIG. 5 is a flowchart illustrating an operation of returning to a video call mode from a voice call mode added to FIG. 2.

Claims (6)

In the video call terminal to support a video call and a voice call, When the first reference value learning setting command is input by the user's operation, the image camera of the mobile communication terminal is driven, the external image of the terminal is taken to generate a video call image, and the brightness distribution of the video call image is statistically processed. A first reference value learning setting step of setting the first reference value; Generating a video call image by capturing an external image of the terminal; Determining brightness of the video call image; Changing the video call mode to a voice call mode when the brightness of the video call image is equal to or less than a first predetermined reference value; Setting the video call terminal to transmit and receive video call data including a video call image and voice data if the current call mode is a video call mode; And Setting the video call terminal to transmit and receive voice data when the current call mode is a voice call mode; Method for automatically switching the call mode between the video call and the voice call configured to include. The method according to claim 1, The video call image brightness determination step, Generating a video call image in Bayer RGB format consisting of R (red), G (green), and B (blue) values through an image camera; And Calculating brightness of the video call image from each of R, G, and B values constituting the video call image; Call mode automatic switching method between the video call and the voice call, characterized in that configured to include. The method according to claim 1, The video call image brightness determination step, Generating a video call image in YUV format composed of Y (brightness information) and U and V (color information) values through an image camera; And Calculating brightness of the video call image from a Y value constituting the video call image; Call mode automatic switching method between the video call and the voice call, characterized in that configured to include. The method according to any one of claims 1 to 3, The call mode automatic switching method, If the current call mode is the voice call mode, determining whether the video call mode is changed from the video call mode to the voice call mode by changing the video call mode to the voice call mode; And If the result of the determination is changed from the video call mode to the current voice call mode, returning the current call mode to the video call mode when the brightness of the video call image changes to a preset second reference value or more; Method for automatically switching the call mode between the video call and the voice call is configured to include more. The method according to claim 4, The step of changing the video call mode to the voice call mode, (C-1) determining whether the current call mode is a video call mode; (C-2) if the current call mode is a video call mode, determining whether the brightness of the video call image falls below the first reference value; (C-3) when the brightness of the video call image falls below the first reference value, determining whether the brightness of the video call image is maintained for more than a preset reference time while being less than the first reference value; And (C-4) changing the video call mode to a voice call mode if the brightness of the video call image is kept below the first reference value for more than the reference time; Call mode automatic switching method between the video call and the voice call, characterized in that configured to include. delete

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