JP2010107773A - Display control device and display control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display control device for setting an optimal character size for each user for a character to be displayed on a screen. <P>SOLUTION: The display control device includes: a means (S307) for extracting a face region from an image and detecting a face size; a means (S306) for storing the character size specified by a user and the detected face size in association with a user ID; a means (S309) for adjusting the stored character size of a corresponding user in response to the change of the face size based on the detected value of the face size and the stored face size; and a means (S311) for creating character information of the adjusted character size. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display control apparatus and a display control method for changing a character size displayed on a display screen according to a distance between the screen and a user.

  A video display device represented by a digital television receiver displays not only video but also menus (character information) for various settings and operations. Since the video has a high degree of redundancy, even if details are not visible, there is little impact, but it is important that the characters and symbols that make up the menu are always visible. Improving the visibility of these letters is also recognized as one of the important issues to be solved for the coming elderly society. Characters are displayed not only as menus but also as electronic program guides, subtitles, and the like.

  Usually, the video display device assumes a specific viewing distance, and the character size (number of fonts of characters) of the menu is determined so that the image can be viewed at that distance. Therefore, it is difficult to visually recognize characters when the user is away from a specific viewing distance. In addition, when the user is closer than a specific distance, it is easy to visually recognize characters, but only a smaller number of characters than the number of characters that can be displayed is displayed, and the display unit is not used effectively. Become. In order to solve this, an image display device that changes the character size according to the distance has been developed (see, for example, Patent Document 1).

  This video display device is provided with a distance measuring unit that measures the distance from the time when the user returns with light. The display information creation unit acquires the program information from the program information storage unit, creates a GUI for the program guide corresponding to the distance to the input device measured by the distance measurement unit, and sends it to the display control unit. Increase the font size if the distance is long.

Since this recorded image display device requires a distance measuring unit that irradiates the user with light and receives the reflected light, the device may be increased in size and cost. Moreover, although the visibility of a character changes for every user especially according to visual acuity, this image display apparatus determines the character size uniformly irrespective of a user. Therefore, when the user's visual acuity is taken into consideration, not all users are necessarily satisfied from the viewpoint of visibility.
JP 2006-3000983 (paragraphs 0015 to 0016)

  As described above, the conventional video display device has a drawback that an optimum character size cannot be set for each user with respect to characters displayed on the screen.

  A display control apparatus according to an aspect of the present invention includes a unit that extracts a face region from an image captured by an imaging unit provided at a predetermined position and detects a face size, and a face size detected by the detection unit. Means for storing the character size in association with the identification information of the photographed user, and the correspondence read from the storage means according to the ratio between the face size detected by the detection means and the face size read from the storage means Means for adjusting the character size of the user, and means for generating character information of the character size adjusted by the adjusting means.

  A display control method according to another aspect of the present invention includes a step of detecting a face size by extracting a face area from a photographed image, and identification information of a user who has photographed the face size and the character size detected by the detection unit, Adjusting the character size of the corresponding user read from the storage unit according to the ratio of the face size read from the storage unit to be stored in association with the detected face size; and the adjusted character size Generating the character information.

  According to the present invention, the size of characters displayed on the screen can be changed based on the distance between the screen and the user. Furthermore, the character size can be set according to individual users. Without measuring the exact distance between the screen and the user, grasp the distance by using the relative perspective relationship based on the face screen size obtained from the user's moving image captured by a general camera Therefore, it is not necessary to use a special distance sensor, and it can be implemented using a camera having no special function, so that it can be realized without increasing the cost and increasing the size of the apparatus.

  Embodiments of a display control device and a display control method according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing the configuration of the display control apparatus according to the first embodiment of the present invention. Here, a television receiver that displays various operation menus as OSD (on-screen display) will be described as an example of a display control device. The television receiver includes at least an antenna 10, a TV tuner unit 20, a video decoding unit 30, a superimposition unit 40, a display 50, a user interface (UI) unit 60, a character data generation unit 70, and a rasterization processing unit. 80, a font storage unit 90, a character size calculation unit 100, a camera 110, an image analysis unit 120, a user information storage unit 130, and a character size information storage unit 140.

  The antenna 10 receives broadcast waves. Here, the antenna 10 can receive terrestrial digital broadcast waves, but is not limited to this, and may receive satellite digital broadcast waves, terrestrial analog broadcast waves, and the like. In the case of digital terrestrial broadcasting, the video encoding method is the MPEG-2 standard, but is not limited to this.

  The TV tuner unit 20 selects a terrestrial digital broadcast wave received by the antenna 10 in accordance with a user's channel selection instruction, and outputs a terrestrial digital broadcast signal of a desired broadcast station.

  The video decoding unit 30 decodes a TV broadcast video signal from a terrestrial digital broadcast signal output from the TV tuner unit 20 and encoded according to the MPEG-2 standard, and includes digital demodulation, error correction, and transport stream. Includes decoding and MPEG-2 video decoding.

  The superimposing unit 40 superimposes the character image output from the rasterization processing unit 80 on the video signal of the TV broadcast that has been MPEG-2 decoded and output from the video decoding unit 30, and is displayed on the screen of the display 50. The menu is displayed for the video that is present.

  The display 50 displays a video and character superimposed signal output from the superimposing unit 40.

  The user interface unit 60 is an interface for the user to give an instruction to the television receiver, and specifically refers to an infrared receiver that receives a control signal (infrared) from a remote controller (not shown). Although there are various user instructions, instructions relating to the present embodiment include an instruction to display a menu indicating various operations on the video, and an instruction to increase or decrease the size of characters constituting the menu. An up (+) or down (-) button provided on the remote control is used for the instruction to change the character size. When the up / down button is pressed once, an instruction to increase or decrease the character size is given.

  The character data generation unit 70 generates character data used for a menu displayed on the screen of the display 50 in response to a user instruction (OSD menu display) output from the user interface unit 60. Specifically, Generate the character code included in the menu.

  The font storage unit 90 stores scalable font information corresponding to the character code of each character, and stores, for example, a TrueType font which is a kind of outline font.

  The rasterization processing unit 80 receives as input the scalable font information read from the font storage unit 90 based on the character data output from the character data generation unit 70 and the character size information output from the character size calculation unit 100. In order to display character information, the image is formed. The term “imaging” as used herein specifically refers to converting a TrueType font into a bitmap format.

  The character size calculation unit 100 calculates the font size of the displayed character. The character size calculation unit 100 includes a storage element that can be realized by a flip-flop, and stores the calculation result in the storage element. Therefore, the value written in the storage element is held until the font size is updated.

  The camera 110 captures a moving image of the face of the user who views the screen of the display 50 and is installed so as to be directed in the same direction as the screen of the display 50. The camera 110 may be externally attached to the housing or frame of the display 50, or may be an integral type. In the case where the display 50 is a flat display such as a liquid crystal panel, if a transparent CCD camera is built in the central portion of the panel, the camera 110 is likely to shoot a user reliably.

  The image analysis unit 120 analyzes a moving image of a face taken by the camera 110 in units of frames, and includes a face detection unit 121, a face correction processing unit 122, a face recognition unit 123, and a face screen size measurement unit 124. It consists of.

  The face detection unit 121 detects a face image by extracting a still image of the user's face area from a moving image of the face input from the camera 110. The face correction processing unit 122 generates a front image of the face using the face image detected by the face detection unit 121.

  The face recognition unit 123 generates face feature information that is an image showing the facial features from the front image of the user's face obtained by the face correction processing unit 122, and associates the facial feature information of unregistered users with the user identification information. Are stored in the user information storage unit 130 and matched with the existing face feature information for each user stored in the user information storage unit 130. The ID that identifies the user as a matching result is supplied to the character size information storage unit 140 and the character size calculation unit 100.

  The technology used in the face detection unit 121, the face correction processing unit 122, and the face recognition unit 123 can be realized by using an existing technology. For example, face authentication described in JP-A-2008-71172 An apparatus may be used. In Japanese Patent Laid-Open No. 2008-71172, the face authentication device is applied to an entrance / exit management device. The entrance / exit management device includes a video camera that captures an image including at least the face of the pedestrian, a face detection tracking unit that detects and tracks the face area of the pedestrian from the image captured by the video camera, and a face used for detection of the face area Face detection dictionary pattern storage unit (memory) storing detection dictionary patterns, face direction determination unit for determining whether or not the face direction of the pedestrian being tracked is facing the front of the video camera, a plurality of dictionaries By collating face authentication dictionary (memory) in which information is registered (stored) in advance, face area images (face images) obtained by the face detection and tracking unit, and dictionary information registered in advance in the face authentication dictionary A face authentication unit that determines whether the pedestrian is a registered person, a gate control unit that controls the door based on the determination result of the face authentication unit, and displays the current face authentication status to the pedestrian Display unit, the pedestrian with respect to speaker as a guide means for guidance by voice, and is configured to have a display authentication control unit which controls the overall control.

  The user information storage unit 130 is a non-volatile storage unit that stores facial feature information for each user generated by the face recognition unit 123, and includes a flash memory and a memory connected to a backup power source. The face feature information is managed (associated) in pairs with an ID for identifying the user.

  The face screen size measuring unit 124 is a part that measures the size of the front image of the user's face obtained by the face correction processing unit 122. In the present embodiment, the face screen size is defined as the number of pixels in the vertical direction (vertical) in the front image of the user's face, but the present invention is not limited to this, and in the horizontal direction (width). Or a diagonal line or a combination thereof. The face screen size is supplied to the character size information storage unit 140 and the character size calculation unit 100.

  The character size information storage unit 140 is a non-volatile storage unit that stores information used to calculate the font size of the character calculated by the character size calculation unit 100, and is a memory to which a flash memory or a backup power supply is connected. Consists of. These pieces of information are also managed (associated) with an ID for identifying the user. The user ID used here matches the ID value used in the user information storage unit 130.

  FIG. 2 shows an example of data stored in the character size information storage unit 140. A character size FNT_DB indicating a basic value of the font size for each user ID, an adjustment coefficient α for changing the character size, and face screen size reference information FCE_DB are stored. The character size FNT_DB is initially set by the user to a size that can be reliably recognized at a certain distance. The face screen size when the character size FNT_DB is initialized is registered as the reference information FCE_DB. This is to detect that the user's distance has changed compared to the initial setting, and to change the character size according to the distance change. That is, at the initial setting immediately after the purchase of the television receiver, each user registers his / her information in the character size information storage unit 140 as follows. When the user determines the character size FNT_DB while viewing the display 50 displaying the menu at a predetermined distance and presses a registration button on a remote controller (not shown), the character size FNT_DB and the face size FCE_DB at that time are displayed as user identification information. It is associated and registered in the character size information storage unit 140. The initial value 1 is registered as the adjustment coefficient α.

  FIG. 2 shows that for a user with ID 1, character size (number of fonts), adjustment coefficient α (no unit), face screen size (number of pixels) are 8, 0.8, 18 and ID 2 , 12, 1, 22 and ID 3 are 20, 1.5 and 16 respectively. The adjustment coefficient α has an initial value of 1, and is updated according to the user's instruction to increase or decrease the character size, as will be described later.

  The character size FNT_CUR of the OSD displayed menu is a distance (in this embodiment, the face screen size is used as a distance index when the distance between the user and the display 50 is changed as compared with the registration in the character size information storage unit 140 of FIG. To change). For example, when the adjustment coefficient α is 1, if the face screen size is halved (distance is doubled), the character size is also doubled. However, since visual acuity varies from user to user, a user may not be able to secure good visibility at a long distance simply by changing the character size according to the distance. Therefore, in the present embodiment, the up (+) and down (-) buttons are provided on the remote control so that the character size can be finely adjusted for each user in a state where the character size is changed according to the change in distance. Is provided. When the up / down button is pressed once, α that increases or decreases the character size by one font is derived, and the adjustment coefficient α in the character size information storage unit 140 is updated.

  Hereinafter, the setting operation of the character size of the menu displayed on the OSD on the screen of the television receiver of the present embodiment will be described with reference to the flowchart of FIG. FIG. 3 is a flowchart of the television receiving apparatus showing processing for one frame related to the above operation, and the processing of FIG. 3 is repeatedly executed for each frame. In the character size information storage unit 140, it is assumed that information for each user as shown in FIG. 2 has already been registered.

  When a menu button on a remote controller (not shown) is operated, the camera 110 captures a moving image of the user watching the display in front of the display 50 and inputs the moving image to the image analysis unit 120. In the face detection unit 121, image processing such as error correction is performed on the image captured by the camera 110 (step S301), and then the face region is cut out (step S302).

  In the face correction processing unit 122, a face front image is generated by performing face correction processing on the face image (step S303). The face front image is input to the face recognition unit 123 to generate face feature information. It is determined whether or not the generated face feature information matches the face feature information of all users stored in the user information storage unit 130 (steps S304 and S305).

  If the matching is successful in step S305, that is, if the generated facial feature information matches any facial feature information stored in the user information storage unit 130, the process proceeds to step S307. If the matching is not successful, the process proceeds to step S306, and the facial feature information generated in the face recognition unit 123 is registered together with the new user ID in order to register the user currently watching the display 50 as a new user. The information is stored in the information storage unit 130, and the process proceeds to step S307.

  In step S307, the face screen size measurement unit 124 calculates the current face screen size FCE_CUR based on the front image of the user's face obtained by the face correction processing unit 122. The face screen size FCE_CUR corresponds to the distance between the display 50 and the current position of the user.

  Next, it is determined whether or not there is an instruction to change the character size from the user interface unit 60, that is, whether or not the up / down button of the remote control is pressed (step S308). This is because in the present embodiment, the character size is uniformly changed regardless of the user identification information based on the change of the face screen size FCE_CUR, and therefore the character size is finely adjusted in consideration of the visual acuity for each user. If there is an instruction to change the character size, calculation processing of an adjustment coefficient α described later is performed (step S310), and then the process proceeds to step S311. If there is no instruction to change the character size, a character size calculation process described later is performed (step S309), and then the process proceeds to step S311. If there is an instruction to change the character size in step S306, the designated character size is set to the value of FNT_CUR. If there is no instruction to change the character size in step S306, the character size FNT_CUR is calculated in step S309.

  For this reason, immediately after step S309 or step S310 is completed, the character size displayed on the screen is fixed, and the character size calculation unit 100 is in a state where the character size FNT_CUR can be output to the rasterization processing unit 80. . In step S <b> 311, the rasterization processing unit 80 outlines the display target character read from the font storage unit 90 based on the character code output from the character data generation unit 70, and the character size output from the character size calculation unit 100. Based on the information FNT_CUR, rasterization processing is executed, and a menu image (character information) of an on-screen display (OSD) layer is created.

  Next, the character information of the OSD layer created in step S311 and the image for one frame after MPEG-2 video decoding output from the video decoding unit 30 are superimposed (step S312), and the menu image superimposed on the video is displayed. The data is output to the display 50 (step S313).

  Details of the processing flow of character size calculation in step S309 in FIG. 3 will be described with reference to FIG.

  First, the character size calculation unit 100 determines whether or not the matching is successful based on the result of the matching process performed by the face recognition unit 123 shown in step S304 of FIG. 3 (step S401). If matching is successful, the process proceeds to step S402. If matching is not successful, the process proceeds to step S403.

  In step S402, the ID of the user who succeeded in matching is acquired from the user information storage unit 130, and character size information FNT_DB corresponding to the user is acquired from the character size information storage unit 140 using the ID. Similarly, face screen size information FCE_DB corresponding to the user is acquired from the character size information storage unit 140 using the matched user ID (step S404).

  Similarly, the value of the character size adjustment coefficient α corresponding to the user is obtained from the character size information storage unit 140 using the matched user ID (step S405).

  Next, in step S406, the character size FNT_CUR is calculated by the following equation, and the process returns to the flow of FIG.

FNT_CUR = α × FCE_DB / FCE_CUR × FNT_DB (1)
Here, FCE_CUR is the value derived in step S307 in FIG. 3 and is output to the character size calculation unit 100 by the face screen size measurement unit 124.

  When the adjustment coefficient α is 1, the expression (1) is, for example, when the face screen size FCE_CUR is halved compared to the time when the user registered the character size FNT_DB in the character size information storage unit 140. This means that the character size FNT_CUR is set to double. It means that by calculating the relative distance between the user and the display 50 based on the relative change in the face screen size, the magnification of the character size is changed in proportion thereto. When the adjustment coefficient α is 1 or more, the character size is larger, and when it is 1 or less, the character size is smaller. Since the adjustment coefficient α can be set for each user, the character size can be adjusted for each user according to the visual acuity.

  Step S403 is processing when matching is not successful in step S401. For example, the previous character size calculation result FCE_CUR held in the storage element of the character size calculation unit 100 is used as it is. The invention is not limited to this. After execution of step S403, the process returns to the flow of FIG.

  Next, the details of the processing flow of α calculation in step S310 in FIG. 3 will be described with reference to FIG.

  First, when the user-specified character size FNT_CUR output from the user interface unit 60 is input to the character size calculation unit 100 (step S501), the character size calculation unit 100 performs face recognition shown in step S304 of FIG. Based on the result of the matching process performed by the unit 123, it is determined whether or not the matching is successful (step S502). If the matching is successful, the process proceeds to step S503, and if the matching is not successful, the process proceeds to step S504.

  In step S503, the ID of the user who has succeeded in matching is acquired from the user information storage unit 130, and character size information FNT_DB corresponding to the user is acquired from the character size information storage unit 140 using the ID. Similarly, face screen size information FCE_DB corresponding to the user is acquired from the character size information storage unit 140 using the matched user ID (step S505).

  In step S506, the value of the character size adjustment coefficient α is calculated by the following equation, and the process proceeds to step S507.

α = (FNT_CUR × FCE_CUR) / (FNT_DB × FCE_DB) (2)
Step S504 is processing when the matching is not successful in step S502. At this time, α is set to 1, and the process proceeds to step S507.

  In step S507, the character size FNT_CUR input in step S501, the face screen size FCE_CUR derived in step S307, and the value of the adjustment coefficient α calculated in step S506 are used as the corresponding user IDs in the character size information storage unit 140 (step If the matching is not successful in S502, it is stored in the portion of the same user ID set in step S306 in FIG. 3, and the previous data is updated. After performing step S507, the process returns to the flow of FIG.

  As described above, according to this embodiment, the moving image of the face of the user who views the screen of the display 50 is captured by the camera 110 provided in the display 50, and the moving image of the face is analyzed in units of frames by the image analysis unit 120. The face detection unit 121 detects a face image, and the face correction processing unit 122 generates a face front image. Based on the front image, face feature information is generated by the face recognition unit 123, and the face size is calculated by the face size measurement unit 124. The face recognition unit 123 stores unregistered user face feature information in association with the user identification information in the user information storage unit 130, and generates the generated face feature information and each existing user stored in the user information storage unit 130. The user who is currently viewing the screen of the display 50 is identified. The matched user identification number is supplied to the character size calculation unit 100 and the character size information storage unit 140. The character size information storage unit 140 stores a character size FNT_DB for each user, a face screen size FCE_DB at the time of registration, and an adjustment coefficient α. The character size calculation unit 100 has a current face screen size value FCE_DB for each user, a character size FNT_DB for each user stored in the character size information storage unit 140, a face screen size FCE_DB at the time of registration, an adjustment coefficient α, The character size FNT_CUR is calculated based on the above.

  Thereby, the size of the character displayed on OSD can be changed based on the distance between the display and the user. The character size can be set according to each user, and the difference in visual acuity of each user can be canceled. Since this setting is stored in a non-volatile memory, once the user sets the character size, there is no need to reset it even if the power is turned off. Without measuring the exact distance between the display and the user, grasp the perspective of the distance using the relative perspective relationship based on the face screen size obtained from the moving image of the user captured by a general camera Therefore, it is not necessary to use a special distance sensor, and it can be implemented using a camera having no special function, so that it can be realized without increasing the cost and increasing the size of the apparatus.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment. For example, in the above description, the television receiver has been described. However, the present invention is not limited to this, and the present invention can be applied to other display devices such as a video recording / reproducing device including an HDD or a DVD, a DVD player, and a PC monitor. is there. Although the user information storage unit 130 and the character size information storage unit 140 are provided separately, the user IDs used for both are the same value, so the character size FNT_DB, α is associated with the user ID in one storage unit. , Face size FCE_DB and face feature information may be stored. Although the text information has been described as a menu displayed superimposed on video information, the present invention is not limited to this, and subtitles superimposed on video may be used, or even when displaying only text information such as a program guide or text broadcasting, The present invention is applicable. Furthermore, not only the characters but also the size of the video itself or the display magnification may be changed in conjunction with the change in the character size. In particular, in the case of parent-child two-screen display, the video on the child screen may be zoomed up / down in conjunction with the change in character size.

  Although the size adjustment for each user is performed using the adjustment coefficient α, the basic size FNT_DB itself can be changed by operating the up / down button without using the adjustment coefficient α.

  The present invention can also be implemented to cause a computer to execute predetermined means, to cause a computer to function as predetermined means, to cause a computer to realize predetermined functions, or as a computer-readable recording medium storing a program. You can also

The figure which shows the structure of the display control apparatus which concerns on one embodiment of this invention. The figure which shows an example of the data stored in the character size information storage part. The flowchart which shows the setting operation | movement of the character size displayed on the screen of the television receiver of this embodiment. The flowchart which shows the character size calculation process in the flowchart of FIG. The flowchart which shows the adjustment coefficient calculation process in the flowchart of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 20 ... TV tuner part, 40 ... Superimposition part, 50 ... Display, 60 ... User interface, 80 ... Rasterization process part, 90 ... Font storage part, 100 ... Character size calculation part, 110 ... Camera, 123 ... Face recognition part, 124 ... Face screen size measuring unit, 130 ... User information storage unit, 140 ... Character size information storage unit.

Claims (9)

Means for extracting a face region from an image photographed by an imaging means provided at a predetermined position and detecting a face size;
Means for storing the face size and the character size detected by the detection means in association with identification information of the photographed user;
Means for adjusting the corresponding user character size read from the storage means according to the ratio of the face size detected by the detection means and the face size read from the storage means;
Means for generating character information of the character size adjusted by the adjusting means;
A display control apparatus comprising: A means for receiving an instruction to change the character size;
The storage means stores the coefficient corresponding to the change instruction in association with the identification information of the user,
The adjustment unit adjusts the character size of the corresponding user read from the storage unit according to the ratio between the face size detected by the detection unit and the face size read from the storage unit and the coefficient. The display control apparatus according to claim 1.   The display control apparatus according to claim 2, wherein the storage unit updates the coefficient every time the change instruction is received.   The display control apparatus according to claim 1, wherein the storage unit includes a non-volatile memory. The character information generated by the generating means is displayed superimposed on the video information by the display means comprising a liquid crystal display panel,
5. The display control apparatus according to claim 1, wherein the imaging unit includes a camera built in a center of the screen of the liquid crystal panel and facing the front of the liquid crystal panel. Extracting a face area from the captured image and detecting a face size;
According to the ratio of the face size read from the storage unit that stores the face size and the character size detected by the detection unit in association with the identification information of the photographed user, and the detected face size, the storage unit Adjusting the text size of the corresponding user read from
Generating character information of the adjusted character size;
A display control method comprising: The storage unit stores a character size adjustment coefficient in association with user identification information,
The adjustment step adjusts the character size read from the storage unit according to a ratio between the detected face size and the face size read from the storage unit for the corresponding user, and the adjustment coefficient. The display control method according to claim 6. A step of accepting an instruction to change the character size;
Updating the adjustment coefficient stored in the storage unit every time the change instruction is received;
The display control method according to claim 7, further comprising: Superimposing the generated character information on video information and displaying it on a liquid crystal display panel;
Photographing a user watching the liquid crystal panel with a camera built in the center of the screen of the liquid crystal panel and facing the front of the liquid crystal panel;
The display control method according to claim 6, further comprising:

Images