Abstract:
Provided is a device and method for transmitting image data that converts 2D image data taken by a digital camera to 3D image data and transmits the 2D and 3D image data to a computer. The image data transmission method that converts 2D image data taken by a digital camera to 3D image data and transmits the 2D and 3D image data to a computer, thereby reducing the required memory capacity and hence the image transfer rate includes extracting contours from the 2D image data taken by the digital camera; and transmitting the contour extraction data to the computer when the extraction of the contours is completed.

Description:
PRIORITY 
       [0001]    This application is a continuation of U.S. application Ser. No. 10/514,391, filed on Nov. 15, 2004, which is based on PCT/KR03/00648 filed on Apr. 1, 2003, the contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a device and method for transmitting image data and, more particularly, to a device and method for transmitting image data that transmits 2D image data taken by a digital camera to a computer, or converts the 2D image data to 3D image data and then transmits the 3D image data to the computer. 
         [0004]    2. Description of the Related Art 
         [0005]    In general, the images displayed on a computer monitor are 2D motion images and, if 3D images are needed, 2D images taken by a digital camera or a camcorder are transmitted to a computer and converted to 3D images by adding separate 2D images on the computer, thereby displaying 3D images. 
         [0006]      FIG. 1  is a schematic of a device for displaying 3D image data according to prior art. 
         [0007]    Referring to  FIG. 1 , the device comprises a digital camera  10  for taking an image of an object to output 2D image data; a frame grabber  12  for converting the 2D image data from the digital camera  10  to 3D image data and displaying the 3D image data; and a signal processor  14  for processing the 3D image data converted from the frame grabber  12  and displaying them on the monitor. 
         [0008]    To construct 3D images, however, the conventional image data transmitting device must receive as many 2D image data as the contours of 3D image from the digital camera  10 , thus requiring a large memory capacity and taking too much time in transmission of 3D image data. 
       SUMMARY OF THE INVENTION 
       [0009]    An object of the present invention is to substantially solve at least the above problems and/or disadvantages and to provide at least the advantages below. 
         [0010]    An aspect of the present invention is a device and method for transmitting image data that transmits 2D image data taken by a digital camera to a computer, or converts the 2D image data to 3D image data and transmits the converted 3D image data to the computer, thereby reducing the required memory capacity and increasing the image transfer rate. 
         [0011]    According to one aspect the present invention, there is provided a device for transmitting 3D image data including a computer for generating a 2D image signal transmit command or a 3D image signal transmit command by manipulation of keys, receiving 3D image signals and displaying them; a digital camera for taking 2D image signals of an object and converting them to digital image signals; a first-in first-out (FIFO) for storing the 2D digital image signals received from the digital camera in a first-in first-out manner; a digital signal processor for controlling extraction of contours necessary for 3D image signals from the 2D digital image signals output from the FIFO and storage and reading-out of the extracted contours, converting the 2D digital image signals to 3D image signals using the stored contour extraction data, and outputting the 3D image signals as serial data; a memory for storing the position and signal magnitude data of the contours extracted from the digital signal processor; a control and communication logic circuit for receiving the 2D image signal transmit command or the 3D image signal transmit command and a ready command from the computer to output a start command or a stop command to the digital camera, and generating the converted 3D image signals from the digital signal processor; and an input/output buffer for buffering input/output data between the computer and the control and communication logic circuit. 
         [0012]    According to another aspect of the present invention, there is provided a method for transmitting 3D image data, which is in a device for transmitting 3D image data that has a digital camera. The method includes (a) extracting contours from 2D image data taken by the digital camera; and (b) transmitting the extracted contour data to a computer when the extraction of the contours is completed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which: 
           [0014]      FIG. 1  is a schematic of a device for displaying 3D image data according to prior art; 
           [0015]      FIG. 2  is a hardware block diagram for the embodiment of the present invention; 
           [0016]      FIG. 3  is a flow chart showing a process for transmitting 3D image signals of a digital signal processor  104  according to the embodiment of the present invention; 
           [0017]      FIG. 4  is a flow chart showing an algorithm for contour extraction according to the embodiment of the present invention; and 
           [0018]      FIG. 5  is a diagram showing the format of contour extraction data according to the embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]    Preferred embodiments of the present invention will be described herein below with reference to the accompanying drawings. In the drawings, the same or similar elements are denoted by the same reference numerals even though they are depicted in different drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. 
         [0020]      FIG. 2  is a hardware block diagram of the embodiment of the present invention. 
         [0021]    Referring to  FIG. 2 , the hardware of the present invention comprises: a computer  112  for generating a 2D image signal transmit command or a 3D image signal transmit command by a manipulation of keys, receiving 3D image signals and displaying them; a first-in first-out (FIFO)  102  for storing 2D digital image signals output from a digital camera  100  in a first-in first-out manner; a digital signal processor (DSP)  104  for controlling extraction of a contour necessary for 3D image signals from the 2D digital image signals output from the FIFO  102  and storage or reading out of the extracted contour, converting the 2D digital image signals to 3D image signals using the stored contour extraction data and then outputting serial data; a image memory  106  for storing the position of the extracted contour received from the digital signal processor  104  and signal magnitude data; a control and communication logic circuit  108  for receiving the 2D image signal transmit command or the 3D image signal transmit command and a ready command from the computer  112 , generating a start or stop command to the digital camera  100  and outputting the converted 3D image signals from the digital signal processor  104 ; and an input/output (I/O) buffer  110  for buffering I/O data between the computer  112  and the control and communication logic circuit  108 . 
         [0022]      FIG. 3  is a flow chart showing a process for transmitting 3D image signals of the digital signal processor  104  according to the embodiment of the present invention;  FIG. 4  is a flow chart showing an algorithm for contour extraction according to the embodiment of the present invention; and  FIG. 5  is a diagram showing the format of contour extraction data according to the embodiment of the present invention. 
         [0023]    Below is a detailed description of the operation for transmitting 3D image signals according to the preferred embodiment of the present invention with reference to  FIGS. 2 to 5 . 
         [0024]    As the user manipulates the computer  112  to generate a scan start command, a scan stop command, a 2D image transmit command or a 3D image transmit command, the command is buffered through the I/O buffer  110  and applied to the control and communication logic circuit  108 . The control and communication logic circuit  108  sends the start command to the digital camera  100  and the 2D image transmit command or the 3D image transmit command to the digital signal processor  104  through a serial data input (SDI). The digital camera  100  receives the start command to start an object shooting operation and sends 2D image data with a write signal to the FIFO  102 , which stores the 2D image data in a first-in first-out manner. The 2D image data output from the digital camera  100  have a grey resolution of 8 bits and a display resolution of 1024.times.1024 and store image data of 1 Mega byte. Once the 2D image data is stored in the FIFO  102 , the digital signal processor  104  processes image signals according to the 2D image transmit command or the 3D image transmit command for transmission of the image signals, which will be described below with reference to  FIG. 2 . 
         [0025]    First, the digital signal processor  104  initializes the system, in step  201 , and checks in step  202  whether or not the 2D image transmit command is received from the computer  112  through the control and communication logic circuit  108 . If the 2D image transmit command is received, the digital signal processor  104  proceeds to step  203  in which it sends a read signal to the FIFO  102  to read out the stored data, stores the data in the memory  106 , synchronizes the stored 2D image data with a serial clock (SCL) and sends them to the control and communication logic circuit  108  through a serial data output (SDO) line. Then the control and communication logic circuit  108  buffers the 2D image data through the I/O buffer  110  via an I/O bus and sends them to the computer  112 . The digital signal processor checks in step  204  whether or not an image transmit stop command is received from the computer  112  through the control and communication logic circuit  108 . If the image transmit stop command is received, the digital signal processor  104  returns to step  202 . If the 2D image transmit command is not received in step  202 , the digital signal processor  104  proceeds to step  204  in which it checks whether or not a 3D image transmit command is received from the computer  112  through the control and communication logic circuit  108 . If the 3D image transmit command is received, the digital signal processor  104  proceeds to step  205  in which it checks whether or not a scan start command is received through the control and communication logic circuit  108 . If the scan start command is received, the digital signal processor  104  proceeds to step  206  in which it sends a read signal to the FIFO  102  to read out the stored 2D image data, extracts a contour necessary for 3D image from the 2D image data and stores the extracted contour in the memory  106 . The algorithm for contour extraction is illustrated in  FIG. 4  and its operation will be described below with reference to  FIG. 4 . 
         [0026]    In step  301 , the digital signal processor  104  sets a row index and a column index at zero in order to acquire a contour height and a signal magnitude from one 2D image data for the first one frame. In step  302 , the digital signal processor  104  checks whether or not the low index is zero (ROW=0). If the row index is zero, the digital signal processor  104  substitutes the contour height and the signal magnitude for variables in order to extract the contour height and the signal magnitude of the 2D image data, in step  303 . Subsequently, the digital signal processor  104  increases the column index by one (COL=COL+1), in step  306 , and checks in step  307  whether or not the column index is less than 1024. If the column index is less than 1024, the digital signal processor  104  returns to step  302 . 
         [0027]    If the row index is not zero in step  302 , the digital signal processor  104  sets the contour height and the signal magnitude and stores the set values in the memory  106 , in step  304 . Here, High[ ] is the position of the contour and Signal[ ] is the signal magnitude. For example, when High[100]=200 and Signal[100]=127, the 100.sup.th position of the contour has a height value of 200 and the signal magnitude (potential energy) is 127. In step  305 , the digital signal processor  104  checks whether or not the current signal magnitude is greater than the previous one. If the current signal magnitude is greater than the previous one, the digital signal processor  104  substitutes the value of the current signal magnitude for the variable in step  306 . The digital signal processor  104  increases the column index by one, in step  307 , and checks in step  308  whether or not the column index is 1024. If the column index is not 1024, the digital signal processor  104  returns to step  302 . Otherwise if the column index is 1024, the digital signal processor  104  sets the column index at zero and increases the row index by one, in step  309 . Subsequently, the digital signal processor  104  checks in step  310  whether or not the row index is 1024. If the row index is not 1024, the digital signal processor  104  returns to step  302 . Otherwise if the row index is 1024, the digital signal processor  104  considers that the image signal for one frame is completely processed, and ends the operation for acquiring the contour height and the signal magnitude. This procedure is repeated to convert more than one 2D image signals to 3D image signals. 
         [0028]    Following the contour extraction, the digital signal processor  104  checks in step  207  whether or not the extraction of the contour from the 2D image signals for one frame is completed. If the contour extraction is completed, the digital signal processor  104  stores the height information High[ ] and the grey information Signal[ ] for the contour extraction data in a data format as shown in  FIG. 5  in the memory  106  and sends the stored 3D image data to the computer  112  via the control and communication logic circuit  108  and the I/O buffer  110 , in step  208 . The 3D image data format shown in  FIG. 5  has height and grey information and requires, for example, 10 bits for representing the height information and 8 bits for the grey information in the case of 1024.times.1024 display resolution and 8-bit grey resolution. Accordingly, two bytes for height information and one byte for grey information, i.e., totally three bytes are required for representing one point of the contour and a memory of 3 Kbytes is used for one contour. Subsequently, the digital signal processor  104  checks in step  209  whether or not the transmission of the 3D image data is completed. If the transmission is completed, the digital signal processor  104  returns to step  202  for transmission of another image data. 
         [0029]    The 3D image is composed of several contours. When the scanning direction of the digital camera  100  is vertical, the contour has horizontal coordinates and height information and the vertical coordinates are determined by the moving distance of the digital camera  100  the moment the digital camera  100  shoots the 2D image. Since the scanning speed is determined at the time of hardware manufacture, the 2D image taken by the digital camera  100  is converted to a 3D image and sent to the computer  112 . Then the computer  112  constructs 3D image data in consideration of the contour information and the moving distance of the camera and displays them. 
         [0030]    As described above, following extraction of the contour from the 2D image signals taken by the digital camera  100  and acquisition of the grey level of each extracted point, the contour and the grey signal for each point on the contour rather than the 2D image data are sent to the computer  112 . The computer  112  can process the 3D image signals only from the height and grey information of the contour. For example, when the X-directional resolution and the height resolution are both 1024 and the number of contours is 512, the prior art must transmit 512 2D images having a resolution of 1024.times.1024. If the grey information is eight bits in this case, the data amount to be transmitted is 4 Gbits (=1024.times.1024.times.512.times.8). However, the present invention, which uses 2 bytes for the height resolution, requires 64 Mbits (=1024.times.16.times.512.times.8), thus reducing the data amount to 1/60. 
         [0031]    As described above, the present invention transmits 2D image data taken by a digital camera, or converts the 2D image data to 3D image data and then transmits the 3D image data to a computer, according to a 2D image transmit command or a 3D image transmit command received from the computer, thereby increasing the transmission speed and reducing the required time for transmitting the 3D image data. Moreover, the present invention uses a DSP technology to reduce the amount of data for conversion of 2D image data to 3D image data and increase the required memory capacity, thereby decreasing the production cost. 
         [0032]    While the invention has been shown and described with reference to a certain preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.