Abstract:
Provided is a an image display device comprising: a tuner selecting a broadcasting signal; a demux separating a video signal, an audio signal and an additional signal from a broadcasting signal selected by the tuner; an up/down scaler with a resolution selected by the user; a display unit for displaying a video signal scaled in the up/down scaler; a key input unit receiving an user command; and a controller controlling the up/down scaler so that a resolution of a video signal displayed in accordance with user commands.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an image display device and an image display method, more particularly, to an image display device displaying an image in compliance with a resolution selected by a user and an image display method.  
         [0003]     2. Description of the Related Art  
         [0004]     A current television technology, a standard definition television (SDTV) has been developed in the mid-twenties century based on a standard analog technology. The disadvantage of the SDTV broadcasting is that an amount of information that the user can watch is limited.  
         [0005]     In order to overcome the disadvantage, a digital TV technology, a high definition television (HDTV) is designed to digitalize and compress a TV signal before the signal is being transmitted, therefore HDTV can transmit more data than SDTV.  
         [0006]     One major advantage of HDTV over SDTV is that the HDTV can transmit more data than SDTV, so the HDTV can transmit a high-resolution image.  
         [0007]     For example, and SD format used in the SDTV has a frame size of 720*480, 704*480 and 640*480, and a HD format used in the HDTV has a frame size of 1920*1080 and 1280*720.  
         [0008]      FIG. 1  is a block diagram showing a conventional image display device, and  FIG. 2  is a flow chart describing a method for displaying an image signal in a conventional image display device.  
         [0009]     As shown in  FIG. 1 , a conventional image display device consists of a tuner  10  that selects a received broadcasting signal, a demux that separates an video signal, a voice signal and an additional information from the broadcasting signal selected in the tuner  10 , a scaler  12  that finds a resolution of a video signal resolution in the demux  11  to scale it to be appropriate to the display unit  13 , a key input portion  15  that inputs a user command, a controller  14  that controls the tuner  10 , the demux  11 , scaler  12  and the display unit  13  in compliance with the user commands in key input portion  15  and a memory  16  storing a broadcasting signal.  
         [0010]     Meanwhile, the conventional display device is configured to display only broadcasting signals with a specific resolution in compliance with its capabilities, and the video signal of an SD format may be displayed, but the video signal of an HD format may not be displayed.  
         [0011]     In addition, as shown in  FIG. 1 , an image display device may have a function for scaling an image signal to be appropriate to the resolution (SD format) of the display unit  13  and down-scaling an image signal of an HD format to display it with a resolution of an SD format.  
         [0012]      FIG. 2  is a flow chart describing an image display method of a conventional image display device.  
         [0013]     The conventional image display device scales an image signal with a resolution appropriate to a display unit when the image signal is received. (S 210 ) (S 220 )  
         [0014]     If a user commands to store an image signal, the image signal, which is scaled to a specific resolution, is stored in the memory, and the image signal is displayed by the display unit. (S 230 ) (S 240 ) (S 250 )  
         [0015]     If there is no user command for storing an image signal, the image signal scaled to a specific resolution is displayed by the display unit. (S 230 ) (S 250 )  
         [0016]     The conventional image display described above does not suggest a method for storing or displaying an image signal with a resolution selected by a user.  
         [0017]     In other words, a user can not display or store a broadcasting signal with a resolution desired by the user. Generally, the image signal resolution is determined to be displayed or stored in compliance with capabilities of an image display device. Thus, it is difficult to satisfy the requests of a user.  
         [0018]     For example, in case of movies or soap operas, the resolution of an image signal is important in compliance with a type of broadcasting programs, and in case of news or sports, where a transmitting the contents is more important than a resolution of an image signal.  
         [0019]     Accordingly, if a user can selects a resolution of image signal to be stored or displayed, it is possible to provide better satisfaction to the user.  
       SUMMARY OF THE INVENTION  
       [0020]     It is an object of the present invention to provide an image display device or a display method to scale image signal to be stored or displayed in compliance with the resolution selected by a user.  
         [0021]     An image display device according to the present invention comprises: a tuner selecting a broadcasting signal; a demux separating a video signal, an audio signal and an additional signal from a broadcasting signal selected by the tuner; an up/down scaler scaling a video signal separated from the demux in compliance with a resolution selected by the user; display unit for displaying an image signal scaled in the up/down scaler; a key input unit receiving a user command; and a controller controlling the up/down scaler so that a resolution of an video signal displayed in compliance with the user command request.  
         [0022]     In addition, an image display method according to the present invention comprises: inputting a video signal; determining a resolution of the video signal; scaling the video signal with a resolution selected by the user; and displaying the scaled video signal.  
         [0023]     Moreover, an image display method according to the present invention comprises: selecting and receiving a broadcasting signal; separating an video signal from the broadcasting signal; determining a resolution of the video signal; scaling and storing the image signal with the first resolution selected by the user; and scaling and displaying the stored image signal with the second resolution selected by the user. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:  
         [0025]      FIG. 1  is a block diagram describing a conventional image display device;  
         [0026]      FIG. 2  is a flow chart describing a method for displaying an video signal in a conventional image display device;  
         [0027]      FIG. 3  is a block diagram describing a configuration of an image display device in accordance with the present invention;  
         [0028]      FIG. 4  is a block diagram describing embodiment of an up/down scaler in an image display device in compliance with the present invention; and  
         [0029]      FIG. 5  is a flow chart describing an image display method in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0030]     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.  
         [0031]      FIG. 3  is a block diagram describing a configuration of an image display device in accordance with the present invention.  
         [0032]     Referring to  FIG. 3 , an image display device in accordance with the present invention includes a tuner  30 , a demux  31 , an up/down scaler  32 , a display unit  33 , a key input portion  35 , a controller  34  and a memory  36 .  
         [0033]     The tuner  30  selects a broadcasting signal selected by a user, and the demux  31  splits a broadcasting signal selected in the tuner  30  into a video signal, an audio signal and an additional signal.  
         [0034]     The key input portion  35  receives a user command, and the user command may be a channel tuning command, a resolution setting command of a user, a storing command of a broadcasting signal and a broadcasting display command.  
         [0035]     The memory  36  may let the user to set a resolution or store a broadcasting signal.  
         [0036]     The up/down scaler  32  up-scales or downscales a resolution of a video signal separated from the demux  31 . In other words, a resolution of the video signal is changed in compliance with a control of the controller  34  with reference to the resolution set by the user.  
         [0037]     The display unit  33  displays a video signal scaled in the up/down scaler  32  or displays a video signal scaled in the up/down scaler  32 , which is stored in the memory  36 .  
         [0038]     An image display device in accordance with the present invention configured as above receives a broadcasting signal of a channel selected by the user through the tuner  30  if a power-on command is input by the key input portion  35 , and the demux  31  divides the received broadcasting signal into a video signal, an audio signal the additional information.  
         [0039]     The controller  34  can extract the information related to a resolution of a video signal from the broadcasting signal. The information related to a resolution of the video signal may be obtained through the additional information.  
         [0040]     A user may execute an on Screen Display (OSD) menu through the key input portion  35  to select a resolution of a video signal by the OSD menu and can be set to display with different resolutions by channels or types of a broadcasting program.  
         [0041]     Note that the channel information and the information type of a broadcasting program can be obtained by the additional information.  
         [0042]     In the meantime, if a resolution of the received video signal is in a SD format, it is changed to a HD format to be stored in the memory  36 .  
         [0043]     In addition, if a resolution of the received video signal is a HD format, it is changed to a SD format to be stored in the memory  36 . In this case, a video signal stored in the memory  36  has a compressed effect result.  
         [0044]     Similarly, a video signal stored in the memory  36  may be displayed in accordance with a user-defined resolution.  
         [0045]     For example, the video in a HD (High Definition) format is down-scaled to a SD (Standard Definition) format to be stored in the memory  36 , and a video signal in a SD format, which is stored in the memory  36  is up-scaled to a HD format to be displayed.  
         [0046]     The change of a resolution in a video signal described above is set by the user.  
         [0047]     Note that the down-scaling is not limited to scaling a video signal of HD format to an image signal of SD format. For example, among video signals in a HD format, a 1920*1080 frame may scale to a 1280*720 frame.  
         [0048]     Similarly, the up-scaling is not limited to scaling a video signal of SD format to a video signal in a HD format. For example, among a video signal in a HD format, a 1280*720 frame may scale to a 1920*1080 frame.  
         [0049]      FIG. 4  is a block diagram describing an embodiment of up/down scaler in an image display device in accordance with the present invention.  
         [0050]     Referring to  FIG. 4 , the up/down scaler  32  includes: a variable length decoder VLD  40  analyzing an input compressed bit-stream, an inverse quantizer IQ  41  quantizing inversely the compressed bit-stream, which is analyzed by the VLD  40  and transforming a DCT coefficient, an inverse discrete cosine transformer IDCT  43  inversely cosine transforming after temporarily storing a bit-stream in a coefficient buffer  42 , which is output in a macroblock type by the inverse quantizer  41 , a motion compensation MC  46  producing a motion compensated pixel value using a motion vector scaled from the motion vector scaler  45 , a macroblock adder  44  adding a data output from the inverse discrete cosine transformer  43  and a data extracted by a control signal of the macroblock and finally a frame memory unit  49  storing a picture data output in the macroblock adder  44  and extracting the corresponding data by the macroblock control signal.  
         [0051]     Here, a motion compensated pixel value extracted in the frame memory unit  49  is temporarily stored in accordance with a control signal of a macroblock to input to the macroblock adder  44  with the data output from the inverse discrete cosine transformer  43 , and the data output from the macroblock adder  44  is temporarily stored in the storing buffer  48  and then stored in the frame memory unit  49 .  
         [0052]     The inverse discrete cosine transformer  43  includes a down transformer and an up transformer.  
         [0053]     The down transformer and the up transformer directly transform a resolution of a video image signal in a frequency domain.  
         [0054]     Specifically, the inverse quantizer transforms a DCT coefficient in order to up-scale or down-scale a resolution of a video signal, and a DCT coefficient inversely cosine transforms to obtain a difference pixel value. A motion vector output from the variable length decoder  40  is scaled in the motion vector pertinent to the block region transformed in the inverse quantizer  41 , and a motion compensated value is obtained in the motion compensator unit  46 .  
         [0055]     Moreover, the macro adder  44  adds a difference pixel value in a macroblock unit obtained from the inverse cosine transformer  43  and a motion compensating value of the pixel obtained in the motion compensator  46  to calculate a final pixel value and then store it in the frame memory  49 .  
         [0056]     As described above, the up/down scaler  32  shown in  FIG. 4  up/down scales a video signal separated in the demux  31  by controls of a control unit  34  in  FIG. 3   
         [0057]     In the meantime, an information of a resolution set by a user may be stored in the memory  36 , the controller  34  controls the up/down scaler  32  with reference to a resolution information stored in the memory  36 .  
         [0058]      FIG. 5  is a flow chart describing an image display method in accordance with the present invention.  
         [0059]     Referring to  FIG. 5 , first, if a user inputs a power-on command, the video signal received will be displayed. (S 101 ) (S 12 )  
         [0060]     It is determined whether the received video signal should be stored or not. Note that determining whether to store the video signal is decided by a predetermined recording set by a user in advance or is determined by a user decision in a real time.  
         [0061]     Next, if a user wants to store the video signal, the user is asked whether to change a resolution of the video signal to store the video signal. (S 104 )  
         [0062]     If a user wants to store a changed resolution of the video signal in a SD format, this signal should be converted to a HD format, and then store the resolution. If the received video signal is in a HD format, the signal should be converted to a SD format, and then store the resolution. (S 105 ) However, a resolution is converted only from the HD format to the SD format, and vice versa, it can be customized in compliance with an user preference. For example, regardless of whether the video signal is in a HD format or in a SD format, a user can store in a 720*480 frame.  
         [0063]     Next, it is determined if storing is done.  
         [0064]     If storing is done, and a user inputs a power-off command, then the process terminates and if not, then the process returns to the step S 102 . (S 107 )  
         [0065]     In the meantime, when displaying the received video signal, a resolution of a video signal is changed to determine whether to display or not.  
         [0066]     If an user wants to change a video display quality, it is determined whether the received video is in a HD format. (S 109 )  
         [0067]     According to the determination results, (S 109 ) if the video signal is in a HD format, the signal is converted to a SD format to be displayed.  
         [0068]     Meanwhile, if the video signal is in a SD format, the video signal is converted to a HD format to be displayed. (S 111 ) Accordingly, if a user wants to change a format, a video signal in a SD format is converted to a HD format to be displayed. (S 112 ) (S 113 )  
         [0069]     In addition, if a user does not want to change a video signal, then the signal is in a SD format.  
         [0070]     Note that a change of a resolution of the video signal is limited to one embodiment; it is possible to change the resolution of a video image in accordance with a user&#39;s preference.  
         [0071]     For example, in case that the video signal stored in a memory as well as the received video signals are displayed, it is possible to change a resolution of the video signal. In other words, the user can store or display a video signal in accordance with a selected resolution, and can store a video signal in accordance with a selected resolution and display the stored image signal in accordance with the stored image signal.  
         [0072]     An image display device and a method for displaying a video according to the present invention can store or display a video signal in accordance with a resolution selected by a user preference, and the present invention has an advantage to display the stored video signal in accordance with a selected resolution.