Abstract:
Provided is a mobile terminal having an image processing function that can perform independent image processing procedure from call processing and a method therefor. The mobile terminal includes: an image sensor for obtaining an image; an image digital processing (DSP) unit for formatting the image into specific image format data; an interface unit for transmitting the specific image format data to an external unit; and a control unit for generating a control signal allowing the specific image format data to be transmitted to the external unit.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a mobile terminal having a function of a personal computer (PC) camera and a method therefor; and, more particularly, to a mobile terminal having a function of PC camera which can perform image data processing as well as call processing, the basic function of a mobile terminal, independently and further implement multimedia services.  
         DESCRIPTION OF RELATED ART  
         [0002]    Mobile terminals, e.g., wireless phones have come into wide use. A major role of the wireless phone is a call processing, but the wireless phone is recently demanded to provide various multimedia functions. Recently, video chatting via computer is all the rage among especially young people. Nevertheless, conventional wireless phones have no PC camera function, even though the conventional wireless phone has a camera. The video chatting via computer requires an expensive camera such as a personal computer (PC) camera additionally.  
         SUMMARY OF THE INVENTION  
         [0003]    It is, therefore, an object of the present invention to provide a mobile terminal having an image processing function that can perform an image processing.  
           [0004]    In accordance with an aspect of the present invention, there is provided a mobile terminal having an image processing function, including: an image sensor for obtaining an image; an image digital processing (DSP) unit for formatting the image into specific image format data; an interface unit for transmitting the specific image format data to an external unit; and a control unit for generating a control signal allowing the specific image format data to be transmitted to the external unit.  
           [0005]    In accordance with another aspect of the present invention, there is provided a method for performing an image processing function in a mobile terminal, including the steps of: a) generating a transmission control signal according to a kind of transmission data to be transmitted; b) if the transmission data is data stored in mobile terminal, transmitting the data through a switching unit to an external unit based on a PC link signal; and c) if the transmission data is image data captured in an image sensor, converting the image data to YUV data, encoding the YUV data to generate encoded data to the external machine through a switching unit based on a PC camera signal.  
           [0006]    In accordance with further another aspect of the present invention, there is provided a method of performing an image processing function in a mobile terminal, including the steps of: capturing an image; formatting the image into a specific image format data; and transmitting the specific image format data to an external unit. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    The above and other objects and features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which:  
         [0008]    [0008]FIG. 1 is a block diagram showing a mobile terminal having an image processing function in accordance with an embodiment of the present invention;  
         [0009]    [0009]FIG. 2 is a block diagram illustrating an image digital signal processor (DSP) installed in the mobile terminal having an image processing function in accordance with the first embodiment of the present invention;  
         [0010]    [0010]FIG. 3 is a block diagram showing a device for controlling the clocks of the image DSP installed in the mobile terminal having an image processing function in accordance with the embodiment of the first present invention;  
         [0011]    [0011]FIG. 4 is a flow chart illustrating an image processing method in a mobile terminal in accordance with the present invention; and  
         [0012]    [0012]FIG. 5 is a block diagram illustrating a mobile terminal having an image processing function in accordance with another embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0013]    Other objects and aspects of the invention will become apparent from the following description of the embodiments with reference to the accompanying drawings, which is set forth hereinafter.  
         [0014]    [0014]FIG. 1 shows a block diagram showing a mobile terminal having an image processing function in accordance with a first embodiment of the present invention. The mobile terminal having an image processing function of the present invention includes a plurality of analogue switches  111  and  112 , a universal serial bus (USB) transceiver  120 , a controller such as a mobile station modem (MSM)  130 , an image digital signal processor (DSP)  140 , and an image sensor  150 .  
         [0015]    As shown, a personal computer (PC)  100  receives data from the mobile terminal through USB lines (D−, D+) coupled thereto. The embodiment of the present invention presents the PC  100  as an example of an external machine. However, other machines such as a printer, an extension USB memory, a USB keyboard, an audio component and the like, can be used instead of the PC as long as they can function as a USB master. Also, the external machine can be connected to the mobile terminal through other connection lines, for example, RS232C data lines as well as the USB lines.  
         [0016]    The analogue switches  111  and  112  are connected to the connection lines coupled with the external machine, respectively, and perform multi-switching operation based on a PC link signal PC_LINK and a PC camera signal PC_CAMERA. When the PC link signal PC_LINK is activated, the analogue switches  111  and  112  provide data paths to the USB transceiver  120 . If the PC camera signal PC_CAMERA is activated, the analogue switches  111  and  112  provide data paths to the image DSP  140 . The analogue switches  111  and  112  are preferably Single Pole Double Throw (SPDT) switches that maintain an open (off) state when both of the PC link signal PC_LINK and PC camera signal PC_CAMERA are inactivated.  
         [0017]    The USB transceiver  120  transmits the data from the MSM  130  to the analogue switches  111  and  112  based on the USB standard.  
         [0018]    The MSM  130  converts the data of the mobile terminal into data suitable to the USB interface. The MSM  130  also activates the PC link signal PC_LINK and the PC camera signal PC_CAMERA.  
         [0019]    The image DSP  140  processes image data from the image sensor  150  and audio data from the outside of the mobile terminal, and generates preview image data and encoded data. Then, the image DSP  140  outputs the encoded data to the analogue switches  111  and  112  or MSM  130 , and outputs the preview image data to be displayed on a liquid crystal display (LCD) device (not shown).  
         [0020]    The image sensor  150  captures images of objects from the outside and outputs the image data to the image DSP  140 .  
         [0021]    In this embodiment of the present invention described above, only for easy description, it is described that the data is transmitted from the mobile terminal to the external machine  100 . However, it is well known to ordinary one skilled in the art that the data can be transmitted from the external machine  100  to the mobile terminal. The mobile terminal having an image processing function provides an independent path between the external machine  100  as a master and the mobile terminal as a slave by using the SPDT switches which control the D+/D− path of the respective USB lines in response to the control of the PC link signal PC_LINK or the PC camera signal PC_CAMERA.  
         [0022]    [0022]FIG. 2 is a block diagram illustrating an image DSP installed in the mobile terminal having an image processing function in accordance with the embodiment of the present invention.  
         [0023]    The image DSP includes a YUV data processing portion  210 , an image parallel processing portion  220 , a Joint Photographic Coding Experts Group (JPEG) codec  230 , a USB transceiver  240  and an image buffer  250 .  
         [0024]    The YUV data processing portion  210  outputs YUV data to Joint Photographic Coding Experts Group (JPEG) codec  230  and the image parallel processing portion  220 . YUV means a color space derived from the phase alternating by line color (PAL) television color standard. Y denotes the luminance channel, U the blue channel, and V the red channel.  
         [0025]    The YUV data processing portion  210  includes a complementary metal oxide semiconductor (CMOS) enhancer  211 , a red/green/blue (RGB) unit  212  and a RGB to YUV resizing unit  213 .  
         [0026]    The CMOS enhancer  211  installed in the YUV data processing portion  210  controls the luminance and brightness of the image data having a RGB format transmitted from the image sensor  150  and outputs the resultant data to the RGB unit  212 .  
         [0027]    The RGB unit  212  of the YUV data processing portion  210  converts the RGB image data from the CMOS enhancer  211  into, for example, 8×8 RGB block data, and outputs the 8×8 RGB block data.  
         [0028]    The RGB to YUV resizing unit  213  of the YUV data processing portion  210  receives the block data of the RGB format from the image sensor  150  and converts them into image data having YUV format (hereinafter, which is referred to as “YUV data”).  
         [0029]    The image parallel processing portion  220  generates output image data based on the YUV data received from the YUV data processing portion  210  which are outputted to the MSM and an LCD device (not shown). To perform the above-described operation, the image parallel processing portion  220  includes a buffer  225 , an output unit  223 , a bus control unit  224 , a reduced instruction set computer (RISC) memory control unit  222  and a master unit  221 .  
         [0030]    The master unit  221  installed in the image parallel processing portion  220  generates preview image data based on data received from the image sensor  150 .  
         [0031]    The RISC memory control unit  222  of the image parallel processing portion  220  transmits the preview image data received from the master unit  221  to the output unit  223 . However, if the size of the preview image is large, the preview image data is transmitted to the output unit  223  through the buffer  225 .  
         [0032]    The output unit  223  of the image parallel processing portion  220  outputs the preview image data received from the buffer  225  and the RISC memory control unit  222  to the bus control unit  224 .  
         [0033]    The bus control unit  224  of the image parallel processing portion  220  outputs the preview image data from the output unit  223  to the LCD device, and provides an image data having a specific format (here, JPEG format) encoded by the JPEG codec  230  through the image buffer  250  to the MSM  130 . The MSM  130  stores the image data having the JPEG format in a predetermined space of a memory.  
         [0034]    The buffer  225  of the image parallel processing portion  220  stores the data from the RGB to YUV resizing unit  213  and the RISC memory control unit  222 , temporarily.  
         [0035]    The JPEG codec  230  receives the YUV data from the YUV data processing portion  210 , and encodes the YUV data into image data having a JPEG format (which is referred to as “JPEG image data”) based on the JPEG method and transmits the JPEG image data to the external machine  100  through the analogue switches  111  and  112 . Here, though the JPEG is a compression technique for coding still images, the JPEG codec  230  encodes a plurality of the still images within a predetermined time (e.g., 33 frames per a second), which are transmitted to the external machine  100  in real time and thus are seen as a moving picture to a user. This is well known to the ordinary one skilled in the art.  
         [0036]    The USB transceiver  240  transmits the JPEG image data to the external machine  100  based on the USB standard. The USB transceiver  240  performs the same function as the USB transceiver  120 . Thus, the USB transceivers  120  and  240  can be can be formed one USB transceiver so that data of both the MSM  130  and the image DSP  140  can be transmitted to a single USB transceiver.  
         [0037]    Hereafter, the operation of the image DSP  140  is described in accordance with the present invention. To execute the preview function, the master unit  221  receives image data captured in the image sensor  150  and generates preview image data. Then the RISC memory control unit  222  receives the preview image data from the master unit  221  and transmits the preview image data to the output unit  223 . If the size of the preview image is large, the preview image is transmitted to the output unit  223  through the buffer  225 . For example, if the user wants to display the preview image having a high resolution, the preview image is encoded into a high resolution image and then transmitted to the output unit  223 . Then, the bus control unit  224  receives the data from the output unit  223  and outputs the preview image data to the LCD device.  
         [0038]    Meanwhile, to describe the data output process of the external machine  100 , first, the CMOS enhancer  211  controls the luminance and brightness of the image data transmitted from the image sensor  150  and outputs the resultant data. Then, the RGB unit  212  converts the data from the CMOS enhancer  211  into 8×8 block data.  
         [0039]    The RGB to YUV resizing unit  213  of the YUV data processing portion  210  receives the data of the RGB format from the image sensor  150  and converts them into YUV data. The YUV data is encoded by the JPEG codec  230 . In this embodiment, the JPEG is described as a coding(compression)/decoding(decompression) method of the YUV data, it is well known to one skilled in the art that other coding/decoding method, e.g., MPEG-4, HL-26L can be used. The encoded YUV data is transmitted to the external machine through the USB transceiver  240  and the analogue switches  111  and  112 , and also transmitted to the MSM through the image buffer  250 .  
         [0040]    Here, by a selection of a user, the YUV data encoded by the JPEG codec  230  is transmitted to the MSM through the image buffer  250  and stored in a predetermined space of a memory (not shown).  
         [0041]    The image DSP  140  may include and control a digital camera having a 330,000-pixel CMOS lens that can process 33 frames per second within a mobile terminal. The image DSP  140  can provide the preview and snap shot function through an LCD device (not shown) and display acquired images on the screen of the external machine  100  through USB data communication.  
         [0042]    The CMOS enhancer  211  adjusts gradation of the image data, YUV data (data before compression), inputted from the image sensor  150  based on a gamma control method, controls the brightness of the image data, and transmits the resultant data to the JPEG codec  230 . The adjusted image data are compressed by the JPEG codec  230  and transmitted to the external machine  100  through the USB lines. Subsequently, in the external machine  100 , the compressed image data are decompressed by the decompression engine installed in the external machine  100 , whereby the image captured by the mobile terminal is displayed on a screen of the external machine  100 .  
         [0043]    [0043]FIG. 3 is a block diagram showing a device for controlling clocks of the image DSP  140  installed in the mobile terminal having an image processing function in accordance with the embodiment of the present invention.  
         [0044]    A basic clock generation unit  310  generates a basic clock (for example, 27 MHz) for the image DSP  140 , and outputs the basic clock to a phase-locked loop (PLL)  320 . Here, the basic clock is provided as a clock signal for elements installed in the image DSP  140  except the USB transceiver  240 .  
         [0045]    The PLL  320  receives the basic clock from the basic clock generation unit  310  and generates an USB clock (48 MHz) for the USB transceiver  240  based on the basic clock. The function of generating clocks is installed within the image DSP  140 , and thus the hardware space and the cost can be saved.  
         [0046]    [0046]FIG. 4 is a flow chart illustrating an image processing method in a mobile terminal in accordance with the present invention.  
         [0047]    At step S 401 , the MSM  130  generates a transmission control signal according to a kind of transmission data to be transmitted. In other words, if the transmission data is the data stored in the mobile terminal, the MSM  130  generates a PC Link signal PC_LINK, and if the transmission data is the image data captured in the image sensor  150 , the MSM  130  generates a PC camera signal PC_CAMERA. At step S 403 , it is determined whether the transmission control signal is the PC link signal PC_LINK or the PC camera signal PC_CAMERA.  
         [0048]    If the transmission data is the data stored in the mobile terminal and the MSM  130  generates the PC link signal PC_LINK, at step S 405 , the MSM  130  reads the data to be transmitted, and at step S 407 , the USB transceiver  120  transmits the data to be transmitted based on the USB standard. At step S 409 , the analogue switches  111  and  112  transmits the converted data to the external machine  100  through the USB lines based on the PC link signal PC_LINK.  
         [0049]    If the transmission data is the image data captured in the image sensor  150 , the MSM  130  generates a PC camera signal PC_CAMERA, at step S 411 , the image DSP  140  receives the image data captured in the image sensor  150 , and at step S 413 , converts the image data to YUV data. The YUV data is encoded based on the JPEC coding method at step S 415 . At step S 417 , the USB transceiver  240  converts the encoded data for the USB standard, and at step S 419  the analogue switches  111  and  112  transmits the converted data to the external machine  100  through the USB lines based on the PC camera signal PC_CAMERA.  
         [0050]    [0050]FIG. 5 is a block diagram illustrating a mobile terminal having an image processing function in accordance with a second embodiment of the present invention. The mobile terminal having an image processing function includes a first analogue switch  511 , a second analogue switch  512 , a USB transceiver  520 , a controller such as an MSM  530 , an image DSP  640  and an image sensor  550 .  
         [0051]    As shown, the PC  500  receives data from the mobile terminal through USB lines (D−, D+). The second embodiment of the present invention presents the PC  500  as an example of external machine. However, other machines such as a printer, an extension USB memory, a USB keyboard, an audio component and the like, can be used instead of the PC as long as they can function as a USB master. Also, the external machine can be connected to the mobile terminal through other connection lines, for example, RS232C data lines as well as the USB lines.  
         [0052]    The first analogue switch  511  is connected to the external machine  500  through a communication line and performs multi-switching operation based on a PC link signal PC_LINK. If the PC link signal PC_LINK is activated, the first analogue switch  511  provides a data path for the USB transceiver  520 . The first analogue switch  511  is preferably a dual SPDT switch, which maintains the open state when the PC link signal PC_LINK is inactivated.  
         [0053]    The second analogue switch  512  is connected to the external machine  500  through a communication line and performs multi-switching operation based on a PC camera signal PC_CAMERA. If the PC camera signal PC_CAMERA is activated, the second analogue switch  612  provides a data path for the image DSP  540 . The second analogue switch  512  is a dual SPDT switch, which maintains the open state when the PC camera signal PC_CAMERA is inactivated.  
         [0054]    The USB transceiver  520  converts the data from the MSM  530  suitable for the USB standard and transmits the converted data to the external machine  500  through the first analogue switch  511  when the PC link signal PC_LINK is activated.  
         [0055]    The MSM  530  converts the data of the mobile terminal into data suitable to the USB transceiver  520  interface. The MSM  530  also activates the PC link signal PC_LINK and the PC camera signal PC_CAMERA.  
         [0056]    The image DSP  540  receives and processes image data from the image sensor  550  and audio data from the outside of the mobile terminal. Then, the image DSP  540  outputs the processed data to the second analogue switch  512 . The image DSP  540  can also display the image data on an LCD device (not shown) and outputs the audio data through an output unit (not shown).  
         [0057]    The image sensor  550  acquires images of objects from the outside and outputs them as image data.  
         [0058]    In the second embodiment of the present invention described above, the mobile terminal having an image processing function provides an independent path between the external machine  500 , a master, and the mobile terminal, a slave, by using SPDT switches to control the D+/D− path of the respective USB lines based on the control of the PC link signal PC_LINK or the PC camera signal PC_CAMERA. The internal circuit configurations of the components described above are the same as those of the first embodiment shown in FIG. 1. Therefore, further description on the second embodiment will be omitted, for the sake of convenience.  
         [0059]    The technology of the present invention has an advantage that image processing can be performed independently without carrying a load on the call process procedure by setting up a device for processing images within the mobile terminal and adopting a switching connection method.  
         [0060]    Further, in addition to a function that stores an image captured by a camera, the mobile terminal of the present invention provides a PC camera function that directly displays an image captured by a camera on a personal computer. Therefore, a user can enjoy a video chatting without using an additional expensive PC camera.  
         [0061]    While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.