Image display device and display control method thereof

Disclosed is an image display device capable of recognizing a hand of a user and predefining an operating region. Image recognition means recognizes the position of a hand of the user. Operating region setup means predefines the operating region, on an imaging region plane of imaging means and around a position on which the user's hand is projected, for the purpose of enabling the user to issue instructions to the image display device. When the position on which the user's hand is projected moves and comes close to the periphery of the operating region, the operating region setup means moves the operating region in the direction of the movement of the position on which the user's hand is projected. Further, the image recognition means recognizes a hand-waving motion of the user, whereas the operating region setup means sets the size of the operating region in accordance with the magnitude of the user's hand-waving motion. Consequently, the image display device provides increased ease of operation and makes it possible to define the operating region in accordance with a user's intention without imposing a significant processing load on itself.

CLAIMS OF PRIORITY

The present application claims priority from Japanese patent application serial no. JP2009-231707, filed on Oct. 5, 2009, the content of which is hereby incorporated by reference into this application.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to an image display device and a display control method thereof. More particularly, the present invention relates to an image display device that visually recognizes a user's gesture to enhance the user-friendliness of an interface giving instructions to an electronic device, and a display control method thereof.

(2) Description of the Related Art

In the past, users of a TV, a video recorder, or other video device or a PC or other information processing device generally entered data or commands with a keyboard or a pointing device, such as a mouse, or performed a channel selection or image display procedure with a remote controller.

Due to the improvement of an image recognition technology in recent years, however, a method of visually recognizing a user's gesture, determining the user's intention in accordance with the result of recognition, and operating a device accordingly has been proposed particularly in the field of gaming devices and operating guide devices.

An image recognition device disclosed, for instance, in Japanese Patent No. 4318056 recognizes the form and motion of hands and fingers and identifies an intended operation.

The image recognition device disclosed in Japanese Patent No. 4318056 creates an operating plane on a marker corresponding to a body position, and recognizes instructions in accordance with the positional movement of a hand or finger in the operating plane. The operating plane is a virtual operating plane. According to Paragraph 0033 of Japanese Patent No. 4318056, “an operator 102 can perform an input procedure with ease by extending his/her hand 601 to an operating plane 701 which is virtually defined in accordance with a marker 101, or by moving the hand 601 so as to touch a part of the screen of a monitor 111 and the operating plane 701 in the same manner as for a touch panel.”

However, the image recognition device disclosed in Japanese Patent No. 4318056 has the following disadvantages because it defines the operating plane in accordance with the body position:

(1) The timing of calibration cannot be determined with ease because the position of the operating plane is determined before the operator extends his/her hand. If, in particular, there are two or more persons in front of the screen, it is practically impossible to select one person as a target for which an operating region is to be defined.
(2) Processing load is increased because the body position is to be recognized.
(3) Positioning is difficult to achieve when, for instance, the operator is in a lying position.

Another conceivable method is to recognize a user's hand and define the region of an operating plane in accordance with the position of the hand. The processing load is low when merely the hand is to be recognized. The reason is that recognition can be achieved with relative ease by grasping the characteristics of the hand.

However, when the above method is used to determine the position of the operating region, it is at a disadvantage in that the timing of calibration cannot be determined with ease.

FIG. 8illustrates a case where the operating region is created near the waist of a user when the user extends his/her hand from below.

When, for instance, the user extends his/her hand from below, the operating region80is created near the user's waist as the moving hand is positioned close to the waist, as shown inFIG. 8. The operating region80created in this manner is positioned apart from an operating region81that is presumed to be handled by the user. Consequently, the user cannot perform an operation with ease.

The present invention has been made to address the above problems, and provides an easy-to-operate image display device that recognizes a user's hand and defines an operating region in accordance with the user's intention without imposing a significant processing load on itself.

SUMMARY OF THE INVENTION

The image display device according to the present invention picks up an image of a user with a camera or other imaging means, causes image recognition means to recognize an image presented by image data acquired by the imaging means, and issues instructions concerning a user's operation in accordance with the result of image recognition. The image recognition means recognizes the position of a hand of the user, and causes operating region setup means to predefine an operating region, on an imaging region plane of the imaging means and around a position on which the user's hand is projected, for the purpose of enabling the user to issue instructions to the image display device. The operating region setup means then moves the operating region within the imaging region plane in accordance with the relative positional relationship between the position on which the user's hand is projected and the operating region. More specifically, when the position on which the user's hand is projected moves and comes close to the operating region, the operating region moves in the direction of the movement of the position on which the user's hand is projected, and is then set at a position reached by the projection of the user's hand. Further, the image recognition means recognizes a hand-waving motion of the user, whereas the operating region setup means sets the size of the operating region in accordance with the magnitude of the user's hand-waving motion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described below with reference toFIGS. 1 to 7.

First Embodiment

First of all, the configuration of an image display device according to the first embodiment of the present invention will be described with reference toFIG. 1.

FIG. 1is a diagram illustrating the configuration of the image display device according to the first embodiment of the present invention.

As shown inFIG. 1, the image display device100according to the present embodiment includes an input unit110, a system control unit120, a video signal processing unit130, and a display unit140.

The input unit110picks up an image of a user. The input unit, for example, is an infrared camera, stereo camera, or RGB camera having a TOF (time-of-flight) sensor function. However, the camera used as the input unit110is not specifically limited to the above-mentioned ones. Any camera may be used as the input unit110as far as it is capable of eventually picking up an image for converting an acquired image to digital data for the purpose of performing image recognition with respect to the user.

The system control unit120detects the position of a hand of the user, and performs data processing to predefine an operating region at an appropriate position. The system control unit120may be implemented by allowing a CPU to execute a software module stored in a memory or by using a dedicated hardware circuit.

The system control unit120includes portions that implement the functions of a hand position detection unit121, a position judgment processing unit122, and an operating region setup unit123.

The hand position detection unit121detects a hand position from digital image data. The position judgment processing unit122determines the positional relationship between the hand position and the operating region. The operating region setup unit123predefines the operating region.

The video signal processing unit130receives instructions and data from the system control unit120and creates a video signal for displaying an image on the display unit140.

The display unit140presents an image to the user in accordance with the video signal. For example, the display unit is an LCD (Liquid Crystal Display), PDP (Plasma Display Panel), or other display device having a display.

An operating region setup process performed by the image display device100according to the first embodiment of the present invention will now be described with reference toFIGS. 2 and 3.

FIGS. 2A and 2Bare diagrams illustrating an operating region that is to be provided by the image display device100according to the first embodiment of the present invention.

FIGS. 3A to 3Care diagrams illustrating the flow of the operating region setup process performed by the image display device100according to the first embodiment of the present invention.

An operation of the image display device100according to the first embodiment of the present invention is as shown inFIG. 2A. First of all, the user30makes a gesture while viewing the display10. The image display device100then recognizes an image of the gesture, determines the operating region in accordance with the result of recognition, and prompts the user30to enter, for instance, a necessary command into the operating region. As shown inFIG. 2B, an infrared camera12is installed under the display10. An LED14of the infrared camera12emits near-infrared rays. A lens16receives resulting reflected rays to pick up an image of the user30. A key point of the present embodiment, in particular, is to recognize a user's hand. The hand32is a part of the body of the user30that is readily recognizable. It is assumed that the employed infrared camera12is a 3D camera capable of measuring the distance between the hand and a display screen.

When the image display device100performs image recognition and detects the hand32, it determines the operating region20relative to an operating screen18of the display10according to the position at which the hand is detected. The operating region20is a virtual region where the user30is supposed to perform an operation. It is assumed that the operating region20is created in an imaging region plane22of the infrared camera12that corresponds to a position at which the user30stands. As shown inFIG. 2B, the operating region20is an enlarged/reduced version of the operating screen18of the display10and positioned in the imaging region plane22in front of the user. At first, the operating region20is determined so that the hand32of the user30is positioned at the center of the operating region20. Then, as shown inFIG. 2B, the operating screen18displays a pointer26at a position corresponding to the position of the hand32of the user30, in the operating region20. Although the pointer26shown inFIG. 2Bis shaped like a hand, it may alternatively be shaped, for instance, like an arrow mark, a circle, square, or other basic form, or a popular animation character.

The operating region20is determined in accordance with the position of the hand32and the distance between the hand32and the operating screen18so that an extended line of the hand32points to the screen. Therefore, the user30can issue instructions to the image display device100in a manner similar to the manner of using a hands-free laser pointer. The operating region20is invisible to the user30. The user30does not particularly have to be aware of the position and size of the operating region. While the user performs a natural operation, the operating region dynamically becomes corrected.

When, for instance, the user30moves his/her hand32rightward within the operating region20as shown inFIG. 3A, the pointer26in the operating screen18also moves rightward. When the hand32is about to move beyond the right end of the operating region20, it is assumed that the operating region20also moves rightward as shown inFIG. 3B. The operating region20can move in this manner as far as the imaging region plane22is not exceeded. In other words, when the position at which the hand32of the user30is detected moves and comes close to the periphery of the operating region20, the operating region20moves in the direction of movement of the position at which the hand32of the user30is detected.

The user30can now perform an operating procedure for the image display device100with respect to the operating region20that is set at a new position. Referring toFIG. 3C, when the user30repositions his/her hand32at the center of the operating region, the pointer26in the operating screen18also appears at the center of the operating screen18.

The steps of the operating region setup process performed by the image display device100according to the first embodiment of the present invention will now be described with reference toFIG. 4.

FIG. 4is a flowchart illustrating the steps of the operating region setup process performed by the image display device100according to the first embodiment of the present invention.

The process for predefining the operating region20is performed by the system control unit120shown inFIG. 1.

First of all, the system control unit120analyzes data fed from the input unit110to perform a process for recognizing the hand32of the user30.

When the hand32is recognized in step S400, step S401is performed to predefine the operating region20in accordance with the position of the hand32. In this instance, the pointer26appears in the operating screen18.

Next, step S402is performed to recognize changes in the position of the hand32and move the pointer26in the operating screen18in accordance with the position of the hand32.

Step S403is then performed to judge whether the hand32is recognized again. If the hand32cannot be recognized (when, for instance, the user30has lowered the hand32or moved the hand32out of the imaging region plane22), step S407is performed to delete the operating region20. In this instance, the pointer26is also deleted from the operating screen18. Upon completion of step S407, the system control unit120returns to step S400.

If, on the other hand, the hand32is recognized, step S405is performed to judge whether the hand32is positioned at an end of the operating region20and about to move out of the operating region. If so, step S408is performed to move the operating region20in accordance with the movement of the hand32. In other words, the operating region20follows the movement of the hand32. Upon completion of step S408, the system control unit120returns to step S402.

When, in step S406, the user32indicates his/her intention to terminate an operation, for instance, by pressing a “Finish” button in the operating region20, the system control unit120terminates the process. If no such indication is given in step S406, the system control unit120returns to step S402.

Second Embodiment

A second embodiment of the present invention will now be described with reference toFIGS. 5 to 7.

A display control method provided by the image display device100according to the first embodiment is implemented by using an interface that causes the operating region to follow the movement of the user's hand. The image display device according to the second embodiment offers an interface that not only provides the same display control method as the first embodiment, but also determines the size of the operating region in accordance with the movement of the user's hand.

First of all, the configuration of the image display device according to the second embodiment of the present invention will be described with reference toFIG. 5.

FIG. 5is a diagram illustrating the configuration of the image display device according to the second embodiment of the present invention.

As shown inFIG. 5, the image display device100according to the second embodiment includes the input unit110, the system control unit120, the video signal processing unit130, and the display unit140, as is the case with the image display device100according to the first embodiment. However, the image display device100according to the second embodiment differs from the image display device100according to the first embodiment in that the system control unit120of the former image display device additionally includes a hand-waving motion detection unit124.

The hand-waving motion detection unit124detects a hand-waving motion of the user30.

The operating region setup process performed by the image display device100according to the second embodiment of the present invention will now be described with reference toFIGS. 6A to 6C.

FIGS. 6A to 6Care diagrams illustrating the flow of the operating region setup process performed by the image display device100according to the second embodiment of the present invention.

In the second embodiment of the present invention, the position and size of the operating region20are calibrated in accordance with the position and magnitude of a hand-waving motion at the beginning of an operation.

When the size of the operating region20is determined in accordance with the magnitude of a hand-waving motion as described above, the user30can intentionally adjust the size of the operating region20. If, for instance, the user30waves his/her hand slightly, a small operating region20ais created as shown inFIG. 6A. If, on the other hand, the user30waves his/her hand greatly, a large operating region20bis created as shown inFIG. 6B.

The above-described hand-waving motion is a distinguishing operation that can easily be differentiated from the other motions (operations).

Further, the use of the above-described hand-waving motion is at an advantage in that an operator can be located even in a situation where two or more persons have extended their hands.FIG. 6Cindicates that the hand32of the user30is waved to generate the operating region20and determine its size, and that the hands33and34of the other persons are irrelevant.

When the above-described operating region setup function based on a hand-waving motion is incorporated, a system for moving the operating region in the direction of the movement of the hand32of the user30can be established by implementing a scheme for dynamically correcting the calibrated operating region.

The steps of the operating region setup process performed by the image display device100according to the second embodiment of the present invention will now be described with reference toFIG. 7.

FIG. 7is a flowchart illustrating the steps of the operating region setup process performed by the image display device100according to the second embodiment of the present invention.

The process for predefining the operating region20is performed by the system control unit120shown inFIG. 5.

First of all, the system control unit120analyzes data fed from the input unit110to perform a process for recognizing the hand32of the user30.

When the hand32is recognized in step S500, step S501is performed to judge whether a hand-waving motion is recognized. If a hand-waving motion is recognized, step S502is performed to predefine the operating region20in accordance with the position and magnitude of the hand-waving motion. In this instance, the pointer26appears in the operating screen18.

Next, step S503is performed to recognize changes in the position of the hand32and move the pointer26in the operating screen18in accordance with the position of the hand32.

Step S504is then performed to judge whether the hand32is recognized again. If the hand32cannot be recognized, step S507is performed to delete the operating region20. In this instance, the pointer26is also deleted from the operating screen18. Upon completion of step S507, the system control unit120returns to step S500.

If, on the other hand, the hand32is recognized, step S505is performed to judge whether the hand32is positioned at an end of the operating region20and about to move out of the operating region. If so, step S508is performed to move the operating region20in accordance with the movement of the hand32. In other words, the operating region20follows the movement of the hand32. Upon completion of step S508, the system control unit120returns to step S503.

When, in step S506, the user32indicates his/her intention to terminate an operation, for instance, by pressing a “Finish” button in the operating region20, the system control unit120terminates the process. If no such indication is given in step S506, the system control unit120returns to step S503.

As described in connection with the first and second embodiments, the display control method of the image display device according to the present invention differs from the conventional technology described in Japanese Patent No. 4318056 and makes it possible to determine the position of the operating region without regard to the position and attitude of the body of a user when the user extends his/her hand. In other words, a person who extends his/her hand can be identified as an operator no matter whether there are two or more persons.

Further, the display control method of the image display device according to the present invention dynamically changes the operating region in accordance with the movement of the user's hand after the operating region is predefined. This provides increased ease of operation because the timing of calibration need not be determined in the middle of an operation.

As described above, the present invention provides an easy-to-operate image display device that recognizes a user's hand and defines the operating region in accordance with the user's intention without imposing a significant processing load on itself.