Patent Publication Number: US-2011063422-A1

Title: Video processing system and video processing method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119(a) from Korean Patent Application No. 2009-00086943, filed on Sep. 15, 2009 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference it its entirety. 
     BACKGROUND 
     1. Field of the Invention 
     Exemplary embodiments of the present general inventive concept relate to a video processing system and method to display a Two-Dimensional (2D) image over a binocular parallax image. 
     2. Description of the Related Art 
     As the human eyes are spaced from each other by a certain distance (about 65 mm), they receive horizontally parallel images. This is called binocular parallax, a major factor which causes a Three-Dimensional (3D) effect when an object is viewed. For the 3D effect, an object is captured by two same cameras spaced from each other by the distance between the two eyes and images captured by the left and right cameras are directed to the left and right eyes, respectively. In this manner, a 3D image is produced. 
     To create 3D images, a video processing system includes a source device and a display device connected to the source device by a High Definition Multimedia Interface (HDMI) cable. 
     The source device displays a binocular parallax image including a left-eye image and a right-eye image stored in a storage medium on the display device. If a display mode is a 3D mode, the display device projects the left-eye image and the right-eye image alternately, thus creating a 3D image. If the display mode is a 2D mode, the display device projects one of the left-eye and right-eye images, thus creating a 2D image. 
     It may occur that during displaying a 3D image, the display device displays a 2D On Screen Display (OSD) image being a menu or button to control the source device over the 3D image. In this case, the source device enlarges or contracts the 2D OSD image, mixes the enlarged or contracted 2D OSD image with the binocular parallax image, and outputs the mixed image on the display device. Under circumstances, the 2D OSD image is mixed across the left-eye and right-eye images or with one of the left-eye and right-eye images. 
     In the 3D mode, the display displays a 3D image by sequentially outputting the left-eye and right-eye images of the binocular parallax image mixed with the 2D OSD image. Compared to outputting only the left-eye or right-eye image of the binocular parallax image mixed with the 2D OSD image, the 2D OSD image may appear overlapped or blurry. 
     SUMMARY 
     Therefore, exemplary embodiments of the present general inventive concept provide a video processing system and method to improve the quality of an OSD image, when the OSD image is overlaid on an image being displayed on a display device. 
     Additional features and utilities of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present general inventive concept. 
     Exemplary embodiments of the present general inventive concept provide a video processing method includes determining whether a display mode of a display device is a 2D mode or a 3D mode, and when the display mode of the display device is the 3D mode and a 2D OSD image is to be overlaid on an image being displayed on the display device, switching the display mode of the display device to the 2D mode so that an image mixed with the 2D OSD image is displayed as a 2D image. 
     The video processing method may further include transmitting a binocular parallax image mixed with the 2D OSD image from a source device to the display device, the binocular parallax image including a left-eye image and a right-eye image, when the display mode is switched to the 2D mode. 
     The binocular parallax image mixed with the 2D OSD image may be transmitted from the source device to the display device, when the display mode is switched to the 2D mode. 
     One of the left-eye and right-eye images of the binocular parallax image may be mixed with the 2D OSD image. 
     It may be determined whether the display mode of the display device is the 2D mode or the 3D mode when a 2D OSD display request is received. 
     It may be periodically determined whether the display mode of the display device is the 2D mode or the 3D mode. 
     The video processing method may further include returning the display mode to the 3D mode when displaying of the 2D OSD image is terminated. 
     Exemplary embodiments of the present general inventive concept also provide a video processing method to output and display a binocular parallax image including a left-eye image and a right-eye image on a display device in a source device, includes determining whether to mix the binocular parallax image with a 2D OSD image, determining whether a display mode of the display device is a 3D mode, when the binocular parallax image is to be mixed with the 2D OSD image, switching the display mode of the display device to a 2D mode, when the display mode of the display device is the 3D mode, mixing one of the left-eye and right-eye images of the binocular parallax image with the 2D OSD image, and transmitting the mixed image to the display device, so that the mixed image is displayed as a 2D image. 
     The mixed image may be transmitted to the display device when the display mode of the display device is switched to the 2D mode. 
     The video processing method may further include returning the display mode of the display device to the 3D mode and transmitting the left-eye and right-eye images of the binocular parallax image to the display device when the binocular parallax image is not mixed with the 2D OSD image. 
     Exemplary embodiments of the present general inventive concept also provide a video processing system that includes a source device to output and display a binocular parallax image including a left-eye image and a right-eye image on a display device, and the display device. The source device can determine whether a display mode of a display device is a 2D mode or a 3D mode, and when the display mode of the display device is the 3D mode and a 2D OSD image is to be overlaid on an image being displayed on the display device, the source device to switch the display mode of the display device to the 2D mode so that an image mixed with the 2D OSD image is displayed as a 2D image. 
     The source device may transmit a binocular parallax image mixed with the 2D OSD image to the display device after the source device switches the display mode of the display device to the 2D mode. 
     The source device may delay the transmission of the mixed image until the display mode of the display is switched to the 2D mode. 
     The source device may mix one of left-eye and right-eye images of the binocular parallax image with the 2D OSD image. 
     The source device may determine whether the display mode of the display device is the 2D mode or the 3D mode, when a 2D OSD display request is received. 
     The source device may periodically determine whether the display mode of the display device is the 2D mode or the 3D mode. 
     The source device may return the display mode to the 3D mode, when displaying of the 2D OSD image is terminated. 
     The source device may include a source controller to control the source device, a video reproducer to reproduce a binocular parallax image recorded in a video recording medium, an OSD generator to generate a 2D OSD image, a scaler to adjust a size of the 2D OSD image, a video mixer to mix the binocular parallax image with the 2D OSD image, a High Definition Multimedia Interface (HDMI) transmitter to transmit an image to the display device, and a Customer Electronics Control (CEC) interface to communicate with the display device in a CEC scheme. 
     Exemplary embodiments of the present general inventive concept also provide a method of controlling a display of an image on a display apparatus, the method including mixing an image to be displayed on the display apparatus with a Two-Dimensional (2D) On Screen Display (OSD) image, switching a display mode of the display apparatus from a Three-Dimensional (3D) mode to a 2D mode, and displaying the mixed image as a 2D image in the 2D mode. 
     The method may include where the mixed image that includes the 2D OSD image is a binocular parallax image having a left eye image and a right eye image. 
     The method may further include determining whether the display apparatus is operating in the 2D mode or the 3D mode, where the display mode is switched to the 2D mode when the operating mode of the display apparatus is determined to be the 3D mode. 
     Exemplary embodiments of the present general inventive concept also provide a video processing system including a display apparatus, a source device to mix an image to be displayed on the display apparatus with a Two-Dimensional (2D) On Screen Display (OSD) image, to switch a display mode of the display apparatus from a Three-Dimensional (3D) mode to a 2D mode, and to output the mixed image as a 2D image to be displayed in the 2D mode. 
     The mixed image that includes the 2D OSD image in the video processing system can be a binocular parallax image having a left eye image and a right eye image. 
     The source device of the video processing system can determine whether the display apparatus is operating in the 2D mode or the 3D mode, and switches the display mode of the display apparatus to the 2D mode when the operating mode of the display apparatus is determined to be the 3D mode. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other features and utilities of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  illustrates a video processing system according to exemplary embodiments of the present general inventive concept; 
         FIG. 2  is a control block diagram illustrating the video processing system according to exemplary embodiments of the present general inventive concept; 
         FIG. 3  illustrates a binocular parallax image in which a left-eye image is mixed with a Two-Dimensional (2D) On Screen Display (OSD) image by a source device illustrated in  FIG. 2 , and a 2D image of the binocular parallax image mixed with the 2D OSD image according to exemplary embodiments of the present general inventive concept; 
         FIG. 4  is a diagram illustrating a signal flow of a video processing method in the video processing system according to exemplary embodiments of the present general inventive concept; 
         FIG. 5  illustrates video processing according to the control operation illustrated in  FIG. 4  according to exemplary embodiments of the present general inventive concept; and 
         FIG. 6  illustrates a video processing system including a source device and a display device having an OSD generator according to exemplary embodiments of the present general inventive concept. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures. 
     A Three-Dimensional (3D) image may be viewed with or without 3D glasses. 
     The principle of 3D imaging with 3D glasses is based on binocular parallax. Specifically, a 3D image can be perceived at the brain of a viewer by presenting separately captured left-eye and right-eye images to the left and right eyes of the viewer, respectively, through 3D glasses. The 3D glasses can include polarized glasses and time-division shutter glasses. The polarized glasses can separate left-eye and right-eye images by shielding one or more images according to the polarization directions of orthogonal polarization devices. The time-division shutter glasses can separate left-eye and right-eye images by blocking and passing light through shutters that can be mounted on glasses in synchronization with the left-eye and right-eye images to create a 3D image. 
     The basic principle of creating a 3D image without 3D glasses can be similar to the 3D imaging using 3D glasses in that stereoscopy relies on binocular parallax and the former differs from the latter in that instead of 3D glasses, devices to separate left-eye and right-eye images can be installed in front of a screen on which an image is displayed to provide the left-eye and right-eye images to the left and right eyes of a viewer, respectively. That is, the devices installed in from of the screen on which an image is displayed manipulate light from a displayed image so that a viewer perceives a 3D image. A parallax barrier and a lenticular scheme can obviate the need for wearing 3D glasses to view a 3D image. When the parallax barrier is used, the viewer can view an image through an opening without 3D glasses. In the lenticular scheme, an array of small lenses can be installed instead of a barrier, where the array of lenses manipulates light of a displayed image so that a viewer perceives a three-dimensional image. 
     A video processing system according to exemplary embodiments of the present general inventive concept can be applied to both 3D imaging with 3D glasses and 3D imaging without 3D glasses. 
       FIG. 1  illustrates a video processing system according to exemplary embodiments of the present general inventive concept. 
     Referring to  FIG. 1 , the video processing system according to the exemplary embodiments of the present general inventive concept can include a source device  10  to output a binocular parallax image including a left-eye image and a right-eye image and a display device  20  to receive the binocular parallax image from the source device  10  and display the binocular parallax image. A cable  30  can communicatively couple the source device  10  to the display device  20 , so that the binocular parallax images can be provided from the source device  10  to the display device  20 . The source device  10  is connected to the display device  20  by a High Definition Multimedia Interface (HDMI) cable (e.g., cable  30 ) according to the High Definition Multimedia Interface Consumer Electronics Control (HDMI-CEC) standard. Alternatively, the binocular parallax images including a left-eye image and a right-eye image can be transmitted from the source device to the display device via a wireless link. A remote control  40  can control the operation (e.g., control the display of video images) of the source device  10  and/or the display device  20 . 
     HDMI can include a High Definition (HD) video signal with a multi-channel audio signal using a single digital interface with a bandwidth of 5 Gbps or above by integrating an Red, Green Blue (RGB) channel, a luminance Y channel, and a chrominance Cr/Cb channel with an audio channel into one channel. HDMI can have three independent communication channels: a Transition Minimized Differential Signaling (TMDS) channel, a Display data Channel (DDC), and a Consumer Electronics Control (CEC) channel. HDMI devices may exchange video data, device information, and control commands with each other through the communication channels. 
     The source device  10  and the display device  20  may be connected to a network by, for example, a CEC communication channel and exchange a plurality of information with each other through CEC communication. The source device  10  can receive display mode information indicating whether a current display mode is a Two Dimensional (2D) or 3D mode from the display device  20  via a CEC line. Apart from the HDMI-CEC, the source device  10  may determine the current display mode of the display device  20  by bi-directional communication with the display device  20 , where the communication medium may include, for example, Ethernet communication. 
     When the source device  10  is notified of the current display mode of the display device  20  via a communication, the source device can mix a 2D On Screen Display (OSD) image with a binocular parallax image, the source device  10  can force, command, and/or request the display device  20  to transition to the 2D mode to display the 2D OSD image on the display device  20 . That is, the display device  20  can display a 2D image. The source device  10  can mix the 2D OSD image with the binocular parallax image according to the current display mode of the display device  20  so as to improve the video quality of the 2D OSD image. 
     The source device  10  can output a binocular parallax image including left-eye and right-eye images stored in a storage medium (e.g., where the storage medium is received by the source device  10 , is mounted in the source device  10 , and/or is received in an interface of the storage device  10 ) to the display device  20 . The display device  20  can generate a 3D image by alternately projecting the left-eye image in an enlarged size or a predetermined normal size, and the right-eye image in an enlarged size or a predetermined normal size. 
     The source device  10 , which supports 3D imaging, can form a frame with a binocular parallax image with a left-eye image and a right-eye image arranged in a side by side layout or in a top and bottom layout. The display device  20  can receive the binocular parallax image and display only the left-eye image in an enlarged size or in a predetermined normal size and then only the right-eye image in an enlarged size or in a predetermined normal size. That is, the display device  20  can display the left-eye image and the right-eye image alternately so as to generate a 3D image. 
     The source device  10  and the display device  20  can be CEC-connected by the HDMI cable (e.g., cable  30  illustrated in  FIG. 1 ) so that they may operate according to a mutual device control function and/or command (e.g., an input command received from the remote control  40 ). A menu and/or manipulation button to control the source device  10  can be displayed on the display device  20 . The source device  10  can generate an OSD signal according to an OSD generation command received, for example, from the remote control  40  and/or other input unit and can display the OSD signal on the display device  20 . 
     In exemplary embodiments of the present general inventive concept, a 2D OSD image can be overlaid on a 3D image that is displayed on the display device  20 . The source device  10  can mix the 2D OSD image with a binocular parallax image and output the mixed image to the display device  20 . If the display device  20  is in the 2D mode, the display device  20  can display a 2D image by outputting one of the left-eye and right-eye images of the mixed image. 
     When the display device  20  is in the 3D mode, the display device  20  can display a 3D image based on binocular parallax by sequentially outputting the left-eye and right-eye images of the mixed image. 
     When the source device  10  outputs the mixed image to the display device  20  in the 3D mode, the 2D OSD image may appear overlapped or blurry because the left-eye and right-eye images of the mixed image are sequentially output. 
     When the source device  10  outputs the mixed image, it can be determined whether the display device  20  is in the 2D or 3D mode in accordance with exemplary embodiments of the present general inventive concept. When the display device  20  is in the 3D mode, the display device  20  can receive a command and/or instruction to transition to the 2D mode. Thus, only an image mixed with the 2D OSD image between the left-eye and right-eye images can be output to a display panel of display device  20 , thus generating a 2D image. As the 2D OSD image does may not appear overlapped or blurry, the video quality of the 2D OSD image can be improved. 
     In the video processing system according to exemplary embodiments of the present general inventive concept, the source device  10  may be an HD DVD player, Blueray DVD Player (BDP) or an HD broadcasting receiver, Set-Top Box (STB), or the like. The display device  20  may be a TV, a projector, etc. 
     For convenience and clarity of description, the following description will be made in the context of a BDP as the source device  10 . 
     Referring to  FIG. 2 , the source device  10  can include a source controller  11  to control to the source device  10 , a video reproducer  12  to play a video stored in a video recording medium, an OSD generator  13  to generate an OSD image, a scaler  14  to adjust the size of the OSD image by enlarging or contracting the OSD image, a video mixer  15  to mix a played image with the OSD image, an HDMI transmitter  16  to transmit an image to the display device  20 , and a CEC interface  17  to transmit and receive a common control signal, i.e. a CEC message to and from the display device  20 . 
     The video reproducer  12  can read compressed left-eye and right-eye images from a video recording medium such as a DVD, an HDD, etc., recover the compressed left-eye and right-eye images to original left-eye and right-eye images by a decoder, and play and/or output a binocular parallax image (e.g., a binocular parallax image signal) with the recovered left-eye and right-eye images. The binocular parallax image can be output to the display device  20  through the video mixer  15  and the HDMI transmitter  15 . 
     The OSD generator  13  can generate an OSD image which can be a menu and/or manipulation button to control the source device  10 . The OSD image can be a 2D image. That is, the generated menu and/or manipulation button by the OSD generator  13  can receive input to control the source device  10 . 
     The scaler  14  can adjust the OSD image received from the OSD generator  13  to a desired size (e.g., a predetermined size, a selected size, and/or any other suitable size to carry out the exemplary embodiments of the present general inventive concept) by enlarging and/or contracting the OSD image. 
     The video mixer  15  can mix the binocular parallax image received from the video reproducer  12  with the OSD image received from the OSD generator  13  and can output the resulting mixed image to the display device  20  through the HDMI transmitter  16 . When the video mixer  15  does not receive an OSD image from the OSD generator  13 , the video mixer  15  can output a binocular parallax image received from the video reproducer  12  to the display device  20 . When the video mixer  15  does not receive a binocular parallax image from the video reproducer  12 , the video mixer  15  can outputs an OSD image received from the OSD generator  13  to the display device  20 . 
     The HDMI transmitter  16  can transmit the image output from the video mixer  15  to an HDMI receiver  26  of the display device  20  via a TMDS line connected to the HDMI receiver  26 . 
     The CEC interface  17  can exchange information with a CEC interface  17  of the display  20  via a CEC line which is a bi-directional bus connected to the CEO interface  17 . The CEC interface  17  can transmit a CEC message requesting information about the display mode of the display device  20  to the CEC interface  27  of the display device  20 , receive a response CEC message from the CEC interface  27  of the display device  20 , interpret the response CEO message, and provide the interpretation result, that is, display mode information to the source controller  11 . The display mode information can include information indicating whether the display mode of the display device  20  is 2D or 3D. The CEC interface  17  may be replaced with a source commutation module having Ethernet communication. 
     The source controller  11  can include a microprocessor to control to the source device  10 , including video reproduction, OSD generation, video mixing, video transmission, and CEC processing according to one or more programs and applications. Alternatively, the source controller  11  can be a field programmable gate array, a programmable logic device, an application specific integrated circuit, and/or any other suitable processor to carry out the exemplary embodiments of the present general inventive concept. 
     The source controller  11  can reproduce a binocular parallax image including compressed left-eye and right-eye images recorded in a video recording medium such as a DVD, an HDD, etc. through the video reproducer  12 . The source controller  11  can transmit the reproduced binocular parallax image to the display device  20  through the HDMI transmitter  16 . The display device  20  can display the binocular parallax image as a 2D or 3D image according to the display mode of the display device  20 . 
     In exemplary embodiments of the present general inventive concept, an OSD image can be mixed with a binocular parallax image, where the source controller  11  generates a 2D OSD image through the OSD generator  13 , mixes the 2D OSD image with the binocular parallax image through the video mixer  15 , and transmits the mixed image to the display device  20  through the HDMI transmitter  16 . Accordingly, the display device  20  can display the mixed image as a 2D image or as both 2D and 3D images according to the display mode of the display device  20 . 
     In exemplary embodiments of the present general inventive concept, an OSD image can be mixed with a binocular parallax image, where the source controller  11  can receive display mode information indicating whether the display mode of the display device  20  is 2D or 3D by communicating with the display device  20  through the CEC interface  17 , before the OSD image is mixed with the binocular parallax image, and can determine the display mode of the display device  20  according to the display mode information. 
     In exemplary embodiments of the present general inventive concept, when a 2D OSD image with a binocular parallax image and the display device  20  may be set in the 2D mode, the source controller  11  can mix the 2D OSD image with one of the left-eye and right-eye images of the binocular parallax image and can transmit the mixed image to the display device  20  through the HDMI transmitter  16 . The source controller  11  can transmit video mixing information of the left-eye or right-eye image mixed with the 2D OSD image to the display device  20  through the CEC interface  17 . Thus, the display device  20  can display the left-eye or right-eye image mixed with the 2D OSD image as a 2D image. The 2D OSD image may not appear overlapped or blurry and thus the video quality of the 2D OSD image may be improved. 
     The source controller  11  may transmit only the mixed image including one of the left-eye and right-eye images and the 2D OSD image (i.e. left-eye image+2D OSD image or right-eye image+2D OSD image) to the display device  20  through the HDMI transmitter  16 . Video mixing information indicating which one of the left-eye or right-eye image is mixed with the 2D ODS image may not be provided to the display device  20 . In exemplary embodiments of the present general inventive concept, when there is no further mixing of the 2D OSD image, the source controller  11  can transmit left-eye and right-eye images to the display device  20 , simultaneously, with returning the display mode of the display device  20  to the 3D mode. 
     In exemplary embodiments of the present general inventive concept, a 2D OSD image with a binocular parallax image and the display device  20  is currently in the 3D mode, the source controller  11  can control the display device  20  to transition to the 2D mode by communicating with the display device  20  through the CEC interface  17 , before the 2D OSD image is mixed with the binocular parallax image. The source controller  11  can mix the 2D OSD image with one of the left-eye (L) and right-eye (R) images of the binocular parallax image (refer to the L image in  FIG. 3 ) and can transmit the mixed image to the display device  20  through the HDMI transmitter  16 . The source controller  11  can transmit video mixing information indicating the left-eye or right-eye image mixed with the 2D OSD image to the display device  20  through the CEC interface  17 . The display device  20  can determine which image between the left-eye and right-eye images was mixed with the 2D OSD image according to the video mixing information and can display only the determined image as a 2D image (refer to a 2D image in  FIG. 3 ). The 2D OSD image may not appear overlapped or blurry and thus the video quality of the 2D OSD image may be improved. 
     The source device  10  may include a remote receiver  25  to receive a signal from a remote control  40 . In exemplary embodiments of the present general inventive concept, the source device  10  can receive a command to display an OSD image with which to control the source device  10  on the display  20  by transmitting a signal to a remote receiver  25  of the display device  20  with the remote control  40  using an HDMI-CEC command and/or message to control the display device  20 . 
     Referring to  FIG. 2  again, the display device  20  can include a display controller  21  to provide overall control to the display device  20 , a video processor  22  to process an image received from the source device  10  to a format to be displayed on a display panel  23 , the display panel  23  to display a final image, a mode switch  24  to switch the display mode of the display device  20  to the 2D or 3D mode, the remote receiver  25  to receive a signal from the remote controller, the HDMI receiver  26  to receive an image from the source device  10 , and the CEC interface  27  to exchange CEC messages with the source device  10 . 
     The mode switch  24  can switch the display mode of the display device  20  to the 2D or 3D mode. In the 2D mode, the display device  20  can display only one of the left-eye and right-eye images of a binocular parallax image received from the source device  10  as a 2D image. In the 3D mode, the display device  20  can display a 3D image according to binocular parallax by sequentially outputting the left-eye and right-eye images of a binocular parallax image received from the source device  10 . 
     The remote receiver  25  can receive a signal from the remote control  40 . 
     The video processor  22  can process an image received from the HDMI receiver  26  according to whether the display device  20  is in the 2D or 3D mode as well as process the video quality, size, etc. of the image according to one or more predetermined parameters (e.g., one or more image size parameters, image resolution parameters, etc.). In the 3D mode, the video processor  22  can display a 3D image according to a binocular parallax on the display panel  23  by sequentially outputting the left-eye and right-eye images of the image received from the HDMI receiver  26 . In the 2D mode, the video processor  22  can display a 2D image on the display panel  23  by outputting only one of the left-eye and right-eye images of the image received from the HDMI receiver  26 . 
     The display panel  23  can display an image received from the video processor  22 . The display panel  23  can include light emitting modules arranged in the form of a square and/or rectangle, each light emitting module including a plurality of light emitters. For example, the display panel  23  can be a Light Emitting Diode (LED), an Organic Light Emitting Diode (OLED), or Liquid Crystal Display (LCD) panel. 
     The HDMI receiver  26  can receive an image from the source device  10  via a TMDS line connected to the HDMI transmitter  16  of the source device  10 . 
     The CEC interface  27  can exchange information with the CEC interface  17  of the source device  10  via a bi-directional bus, that is, a CEC line connected to the CEC interface  17 . The CEO interface  27  can receive a CEC message from the source device  10 , interpret the received CEC message, and output the interpretation result to the display controller  21 . The CEC interface  27  can receive a CEC message carrying display mode information about the display device  20  from the display controller  21  and can transmit the CEC message to the CEC interface  17  of the source device  10 . As described above, the display mode information can include information indicating whether the display device  20  is in the 2D or 3D mode. The CEC interface  27  may be replaced with a display communication module supporting Ethernet communication. 
     The display controller  21  can process an image received from the HDMI receiver  26  through the video processor  22  according to whether the display device  20  is in the 2D or 3D mode. Specifically, when the display mode of the display device  20  is the 3D mode, the display controller  21  can display a 3D image according to binocular parallax on the display panel  23  by sequentially outputting the left-eye and right-eye images of the image received from the HDMI receiver  26 . When the display mode is the 2D mode, the display controller  21  can display a 2D image on the display panel  23  by outputting only one of the left-eye and right-eye images of the image received from the HDMI receiver  26 . 
     The display controller  21  can collect display mode information about the display device  20  upon receipt of a display mode information request through the CEC interface  27  and/or periodically, and can transmit the collected display mode information to the source device  10  through the CEC interface  27 . Therefore, the source device  10  may identify whether the display mode of the display device  20  is the 2D or 3D mode. 
     The display controller  21  can receive video mixing information indicating which one of left-eye or right-eye images is mixed with a 2D OSD image through the CEC interface  27 , can receive the left-eye or right-eye images of a binocular parallax image mixed with the 2D OSD image through the HDMI receiver  26 , and can determine whether the display device  26  is in the 2D or 3D mode. When the display device is in the 3D mode, the display controller  21  can display a 3D image by sequentially outputting the left-eye and right-eye images of the mixed image to the display panel  23  through the video processor  22 . The 2D OSD image may appear overlapped or blurry. When the display device  20  is in the 2D mode, the display controller  21  can display a 2D image by outputting only the image mixed with the 2D OSD image between the left-eye and right-eye images of the mixed image to the display panel  23  through the video processor  22  so that the 2D OSD image does not appear overlapped or blurry. 
       FIG. 6  illustrates a video processing system including a source device  10  and a display device  20   a  having a video processor  22   a  including an OSD generator  13   a , a scaler  14  and a mixer  15   a  according to exemplary embodiments of the present general inventive concept. The source device  10  may be the same as described above, or, alternatively, may not include one or more of the OSD generator  13 , the scaler  14   a , and the video mixed  15 . The display device  20   a  can include a CEC interface  27 , a HDMI receiver  26 , a mode switch  24 , the display panel  23  and the remote receiver  25 , which are described above in detail. 
     In the video processing system illustrated in  FIG. 6 , the HDMI receives video signals via the TDMS line with the HDMI receiver  26 . The display controller  21  can provide the video signal from the HDMI receiver to the video processor  22   a . Video images  12   a  can be the video images received from the HDMI processor to be combined with OSD images generated by the OSD generator  13   a . The scaler  14   a  can adjust the size of the OSD image generated by the OSD generator  13   a  by enlarging or contracting the OSD image, and the video mixer  15   a  can mix the video images  12   a  with the generated and scaled OSD image. The output of the video mixer  15   a  that includes the video images and the OSD images can be displayed on a display panel  23  as described above. 
     Here, when the images to be displayed are in a 2D mode, the display controller  21  may not change to the 2D mode to insert the OSD images. However, when in the 3D mode, the display controller  21  may change the 3D mode into the 2D mode to insert the OSD images thereto in a similar method as described above in connection with  FIGS. 1-5 . 
       FIG. 3  illustrates a binocular parallax image including a right-eye image and a left-eye image that is mixed with a 2D OSD image, and a 2D image of the mixed image on the display device  20  according to exemplary embodiments of the present general inventive concept. 
     Referring to  FIG. 3 , the source device  10  can mix only the left-eye (L) image with a 2D OSD image  50  and can output only the L image mixed with the 2D OSD image  50  to the display panel  23 . As the display panel  23  can display the mixed image as a 2D image, the 2D OSD image can appear clear without overlapping or blur. 
       FIG. 4  is a diagram illustrating a signal flow for a video processing method in the video processing system according to exemplary embodiments of the present general inventive concept. For convenience and clarity of description, it is assumed that the display device  20  operates initially in the 3D mode and displays a binocular parallax image received from the source device  10  in the 3D mode. 
     Referring to  FIG. 4 , the source device  10  can transmit a left-eye (L) image and a right-eye (R) image recorded in a video recording medium such as a DVD, an HDD, etc. to the display device  20  by playing the video recording medium at operation  100 . 
     The display device  20  can display a 3D image by alternately outputting the left-eye and right-eye images received from the source device  10  to the display panel  23  at operation  101  (refer to images L 1  and R 1  in  FIG. 5 ). 
     In operation  102 , the display device  20  can transmit to the source device  10  display mode information indicating whether the current display mode of the display device  20  is the 2D or 3D mode when displaying the 3D image. 
     Upon receipt of the display mode information, the source device  10  can identify the current display mode of the display device  20  as the 3D mode by analyzing the display mode information and can store the display mode information in its memory in step  103 . 
     Upon receipt of an OSD display request via the remote control  40  and/or other input device in operation  104 , the source device  10  can notify the display device  20  that a 2D OSD image can be output by transmitting 2D OSD output indication information in operation  105 . The display device  20  can transmit an ACKnowledgment (ACK) signal including information about a time to transition from the 3D mode to the 2D mode in operation  106 . In operation  107 , the display device  20  can transition from the 3D mode to the 2D mode according to a command and/or control signal. Along with the mode transition, the display device  20  can transmit display mode information indicating the 2D mode to the source device in operation  108 . When transitioning from the 2D mode to the 3D mode, the display device  20  may notify the user that the display mode can switch from the 3D mode to the 2D mode, before the mode transition. If the user does not want the mode transition, the display device  20  may be maintained in the 3D mode. 
     Upon receipt of the ACK signal, the source device  10  can generate a user-requested 2D OSD image in operation  109 , can mix the 2D OSD image with a binocular parallax image, for example, only with the left-eye image of the binocular parallax image in operation  110 , and can transmit the mixed image to the display device  20  after a predetermined amount of time, taking into account the mode transition time of the display device  20  in operation  111 . The source device  10  can transmit to the display device  20  video mixing information indicating that the left-eye image was mixed with the 2D OSD image. 
     Upon receipt of the left-eye image mixed with the 2D OSD image, the right-eye image of the binocular parallax image, and the video mixing information from the source device  10 , the display device  20  can display a 2D image by outputting only the left-eye image mixed with the 2D OSD image to the display panel  23  according to the video mixing information in step  112  (refer to images L 2 , L 3  and L 4  in  FIG. 5 ). The 2D OSD image can be displayed clear without overlapping or blur, thus improving the video quality of the 2D OSD image. 
     When displaying of the 2D OSD image is terminated after a predetermined period of time or by a received input during displaying the 2D image, the source device  10  can notify the display device  20  that the 2D OSD image is not displayed any longer by transmitting information indicating outputting of left-eye (L) and right-eye images without the 2D OSD image to the display device  20  in operation  113 . 
     In operation  114 , the display device  20  can switch the display mode from the 2D mode to the 3D mode. The source device  10  can transmit the left-eye and right-eye images which are not mixed with the 2D OSD image to the display device  20  in operation  115 . 
     Then the display device  20  can display a 3D image by sequentially outputting the received left-eye and right-eye images to the display panel  23  in operation  116  (refer to images I 5  and R 5  in  FIG. 5 ). 
       FIG. 5  illustrates screens that display video frames output from the source device as 2D or 3D images according to the video processing method according to exemplary embodiments of the present general inventive concept. 
     Referring to  FIG. 5 , video frames in an upper part of  FIG. 5  can be consecutive video frames output from the source device  10  to the display device  20 . Each of the video frames includes a pair of left-eye and right-eye images. L 1  and R 1 , L 2  and R 2 , L 3  and R 3 , L 4  and R 4 , or L 5  and R 5 . 
     Among the consecutive video frames, the images L 2 , L 3 , and L 4  can be mixed with 2D OSD images. 
     When the source device  10  outputs the consecutive video frames to the display device  20 , the display device  20  can display the video frames without 2D OSD images, L 1  and R 1 , and L 5  and R 5  as 3D images. 
     The display device  20  can display the video frames with 2D OSD images, L 2  and R 2 , L 3  and R 3 , and L 4  and R 4  as 2D images so that the 2D images do not appear overlapped or blurry. 
     As is apparent from the above description, when a 2D OSD image is overlaid on a 3D image based on binocular parallax being displayed on a display device, the 2D OSD image can be displayed normally without overlapping or blur according to the exemplary embodiments of the present general inventive concept a disclosed herein. 
     Although several embodiments of the present general inventive concept have been illustrated and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the claims and their equivalents.