Abstract:
A method for transmitting a three-dimensional (3D) image is provided. The 3D image is transmitted via an image transmission interface according to a 2D image data format. The method includes steps of: receiving a 2D image data and an image depth data; down-sampling the 2D image data to generate an image sampling data; and transmitting the 3D image comprising the image sampling data and at least one part of the image depth data via the image transmission interface.

Description:
[0001]    This application claims the benefit of Taiwan application Serial No. 100134864, filed Sep. 27, 2011, the subject matter of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates in general to a method and apparatus for transmitting an image, and more particularly to a method and apparatus for transmitting a three-dimensional (3D) image. 
         [0004]    2. Description of the Related Art 
         [0005]    Referring to  FIGS. 1 and 2 ,  FIG. 1  shows a schematic diagram of transmitting a two-dimensional (2D) image;  FIG. 2  shows a schematic diagram of transmitting a 3D image. An image data is transmitted via an image transmission interface. A current image transmission interface includes LVDS, Mini-LVDS, VbyOne-HS, iDP, DP or EPI, and transmits an image in an image transmission format including RGB444, YUV444 and YUV422. A 2D image display receives a 2D image data  10   a  in  FIG. 1  to display a 2D image. A 3D image display receives a 3D image data  20  in  FIG. 2  to display a 3D image. The 3D image data  20  includes a 2D image data  10   a  and an image depth data  10   b.  The image depth data  10   b  has a bit width the same as a bit width of the 2D image data  10   a.  The image transmission interface transmits the image depth data  10   b  after having transmitted the 2D image data  10   a.    
         [0006]    The image transmission interfaces needs to transmit the image depth data  10   b  besides the 2D image data  10   b,  and so an additional bandwidth is required in order to complete the transmission of the 3D image data. Further, since the 2D image data and the image depth data are individually transmitted at separate time points, an additional frame buffer is also required for storing the 2D image data and the image depth data received at different time points in order to complete subsequent image processing. 
       SUMMARY OF THE INVENTION 
       [0007]    The invention is directed to a method and apparatus for transmitting a three-dimensional (3D) image. 
         [0008]    A method for transmitting a 3D image is provided by the present invention. The 3D image is transmitted via an image transmission interface according to a 2D image data format. The method includes steps of: receiving a 2D image data and an image depth data; down-sampling the 2D image data to generate an image sampling data; and transmitting the 3D image comprising the image sampling data and at least one part of the image depth data via the image transmission interface. 
         [0009]    An apparatus for transmitting a 3D image is further provided by the present invention. The apparatus transmits the 3D image according to a 2D image data format. The apparatus includes a receiving circuit, a down-sampling circuit and a data reconstructing circuit. The receiving circuit receives a 2D image data and an image depth data. The down-sampling circuit is coupled to the receiving circuit, and down-samples the 2D image data to generate an image sampling data. The data reconstructing circuit is coupled to the down-sampling circuit, and transmits the 3D image comprising the image sampling data and at least one part of the image depth data according to a 3D image data format via the image transmission interface. A data bandwidth of the 3D image data format is the same as a data bandwidth of the 2D image data format. 
         [0010]    The above and other aspects of the invention will become better understood with regard to the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a schematic diagram of transmitting a 2D image data. 
           [0012]      FIG. 2  is a schematic diagram of transmitting a 3D image data. 
           [0013]      FIG. 3  is a schematic diagram of a 2D image data format RGB444. 
           [0014]      FIG. 4  is a schematic diagram of a 2D image data format YUV444. 
           [0015]      FIG. 5  is a schematic diagram of a 2D image data format YUV422. 
           [0016]      FIG. 6  is a flowchart of a 3D image transmitting method according to a first embodiment of the present invention. 
           [0017]      FIG. 7  is a schematic diagram of a 3D image data format according to the first embodiment of the present invention. 
           [0018]      FIG. 8  is a flowchart of a 3D image transmitting method according to a second embodiment of the present invention. 
           [0019]      FIG. 9  is a schematic diagram of a 3D image data format according to the second embodiment of the present invention. 
           [0020]      FIG. 10  is a schematic diagram of a 10-bit 2D image data format RGB444. 
           [0021]      FIG. 11  is a bit transmission format defined by a low-voltage differential signaling (LVDS) image transmission interface. 
           [0022]      FIG. 12  is a flowchart of a 3D image transmitting method according to a third embodiment of the present invention. 
           [0023]      FIG. 13  is a schematic diagram of a 3D image data format according to the third embodiment of the present invention. 
           [0024]      FIG. 14  is a flowchart of a 3D image transmitting method according to a fourth embodiment of the present invention. 
           [0025]      FIG. 15  is a schematic diagram of a 3D image data format according to the fourth embodiment of the present invention. 
           [0026]      FIG. 16  is a schematic diagram of a 3D image transmitting apparatus according to the first embodiment of the present invention. 
           [0027]      FIG. 17  is a schematic diagram of a 3D image transmitting apparatus according to the second embodiment of the present invention. 
           [0028]      FIG. 18  is a schematic diagram of a 3D image transmitting apparatus according to the third embodiment of the present invention. 
           [0029]      FIG. 19  is a schematic diagram of a 3D image transmitting apparatus according to the fourth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]      FIG. 3  shows a schematic diagram of RGB444 as an example of a 2D image data format. When an image transmission interface transmits a 2D image data, the 2D image data may be transmitted according to the 2D image data format RGB444 in  FIG. 3 . For example, each pixel data in a 2D image data includes a red component, a green component and a blue component. For example, a 1 st  pixel data includes a red component R 1 , a green component G 1  and a blue component B 1 , a 2 nd  pixel data includes a red component R 2 , a green component G 2  and a blue component B 2 , and so forth. An n th  pixel data includes a red component R n , a green component G n  and a blue component B n . The image transmission interface sequentially transmits the 1 st  pixel data to the n th  pixel data to complete the transmission of a 2D image data  10   b.    
         [0031]      FIG. 4  shows a schematic diagram of YUV444 as an example of a 2D image data format. When an image transmission interface transmits a 2D image data, the 2D image data may also be transmitted according to the 2D image data format YUV444 in  FIG. 4 . For example, each pixel data in a 2D image data includes a luma component, a first chrominance component and a second chrominance component. For example, a 1 st  pixel data includes a luma component Y 1 , a first chrominance component U 1  and a second chrominance component V 1 , a 2 nd  pixel data includes a luma component Y 2 , a first chrominance component U 2  and a second chrominance component V 2 , and so forth. The image transmission interface sequentially transmits the 1 st  pixel data to the n th  pixel data to complete the transmission of a 2D image data  10   b.    
         [0032]      FIG. 5  shows a schematic diagram of YUV422 as an example of a 2D image data format. When an image transmission interface transmits a 2D image data, the 2D image data may also be transmitted according to the 2D image data format YUV422 in  FIG. 5 . A main difference between YUV444 and YUV422 is that, a first chrominance component and a second chrominance component are shared by two luma components in YUV422. For example, luma components Y 1  and Y 2  share a first chrominance component U 1  and a second chrominance component V 1 , and luma components Y 3  and Y 4  share a first chrominance component U 3  and a second chrominance component V 3 , and so forth. That is, luma components Y n−1  and Y n  share a first chrominance component U n−1  and a second chrominance component V n−1 . 
       First Embodiment 
       [0033]    Referring to  FIGS. 6 ,  7  and  13 ,  FIG. 6  shows a flowchart of a 3D image transmitting method according to a first embodiment of the present invention;  FIG. 7  shows a 3D image data format according to the first embodiment of the present invention;  FIG. 16  shows a schematic diagram of a 3D image transmitting apparatus according to the first embodiment of the present invention. A 3D image transmitting apparatus  7  includes a receiving circuit  71 , a down-sampling circuit  72  and a data reconstructing circuit  73 . The 3D image transmitting apparatus  7  and the 3D image transmitting method are applied to an image transmission interface. 
         [0034]    The method includes the following steps. In Step  31 , the receiving circuit  71  receives a 2D image data S 1  and an image depth data S 2 . 
         [0035]    In Step  32 , the down-sampling circuit  72  down-samples the 2D image data S 1  to generate an image sampling data S 11 . In the first embodiment, YUV422 as a sampling format of the image sampling data is taken as an example. The image sampling data S 11  includes luma components Y 1  to Y n , first chrominance components U 1 , U 3 , U 5  . . . to U n−1 , and second chrominance components V 1 , V 3 , V 5  . . . to V n−1 . The luma components Y 1  and Y 2  share the first chrominance U 1  and the second chrominance component V 1 , the luma components Y 3  and Y 4  share the first chrominance U 3  and the second chrominance component V 3 , and so forth. That is to say, the luma components Y n−1  and Y n  share the first chrominance component U n−1  and the second chrominance component V n−1 . 
         [0036]    In a human visual system, human eyes are more sensitive to brightness changes more than to color changes. Therefore, for human eyes, the luma component is regarded as more important than the first chrominance component and the second chrominance component. By down-sampling the first chrominance component and the second chrominance component, a data transmission amount can be reduced and the data bandwidth accordingly saved can be utilized for subsequently transmitting the image depth data. 
         [0037]    In Step  33 , the data reconstructing circuit  73  transmits the image sampling data S 11  and the image depth data S 2  according to the 3D image data format in  FIG. 7 . The 3D image data format in  FIG. 7  has a data bandwidth the same as a data bandwidth of the 2D image data format RGB444 in  FIG. 3  or a data bandwidth of the 2D image data format YUV444 in  FIG. 4 . The luma components Y 1  to Y n  are outputted via a first channel; and the first chrominance component U 1  and the second chrominance component V 1 , the first chrominance component U 3  and the second chrominance component V 3 , . . . , and the first chrominance component U n−1  and the second chrominance component V n−1  are outputted via a second channel. The image depth data D 1  to D n  are outputted via a third channel. 
         [0038]    As described, in the first embodiment, 3D image transmission can be completed through the data bandwidth the same as the data bandwidth of the 2D image data format RGB444/YUV444. Therefore, the first embodiment can transmit the 3D image without requiring an additional data bandwidth. Further, the 2D image data and the image depth data can be simultaneously transmitted, and so no additional frame buffer is required to further reduce production costs. 
       Second Embodiment 
       [0039]    Referring to  FIGS. 8 ,  9  and  17 ,  FIG. 8  shows a flowchart of a 3D image transmitting method according to a second embodiment of the present invention;  FIG. 9  shows a 3D image data format according to the second embodiment of the present invention;  FIG. 17  shows a schematic diagram of a 3D image transmitting apparatus according to the second embodiment of the present invention. A main difference between a 3D image transmitting apparatus  8  and the 3D image transmitting apparatus  7  is that, the down-sampling  72  in the 3D image transmitting apparatus  8  further down-samples the depth image data S 2  to generate a depth sampling data S 21 . The data reconstructing circuit  73  transmits the image sampling data S 11  and the image depth data S 21  according to the 3D image data format in  FIG. 9 . The 3D image transmitting apparatus  8  and the 3D image transmitting method are applied to an image transmission interface. 
         [0040]    The method includes the following steps. In Step  41 , the receiving circuit  71  receives the 2D image data S 1  and the image depth data S 2 . 
         [0041]    In Step  42 , the down-sampling circuit  72  down-samples the 2D image data S 1  to generate the image sampling data S 11 . In the second embodiment, YUV420 as a sampling format of the image sampling data is taken as an example. That is, the image sampling data S 11  is a first chrominance component and a second chrominance component of a pixel sampled from every four pixels, so that a data amount of the first chrominance component and the second chrominance component of the image sampling data S 11  is one-fourth of a data amount of the first chrominance component and the second chrominance component of the 2D image data S 1 . The image sample data S 11  includes luma components Y 1  to Y n , first chrominance components U 1 , U 5 , U 9  . . . to U n−3 , and second chrominance components V 1 , V 5 , V 9  . . . to V n−3 . The luma components Y 1  to Y 4  share the first chrominance U 1  and the second chrominance component V 1 , the luma components Y 5  to Y 8  share the first chrominance U 5  and the second chrominance component V 5 , and so forth. That is to say, the luma components Y n−3  to Y n  share the first chrominance component U n−3  and the second chrominance component V n−3 . 
         [0042]    In a human visual system, human eyes are more sensitive to brightness changes more than to color changes. Therefore, for human eyes, the luma component is regarded as more important than the first chrominance component and the second chrominance component. By down-sampling the first chrominance component and the second chrominance component, a data transmission amount can be reduced and the data bandwidth accordingly saved can be utilized for subsequently transmitting the image depth data. 
         [0043]    In Step  43 , the down-sampling circuit  72  down-samples the image depth data S 2  to generate the depth sampling data S 21 . In the second embodiment, the depth sampling data S 21  is a pixel sampled from every two pixels of the image depth data S 2 , and so a data amount of the depth sampling data S 21  is one-half of a data amount of the image depth data S 2 . The depth sampling data S 21  includes image depth data D 2 , D 4  . . . and D n . 
         [0044]    In Step  44 , the data reconstructing circuit  73  transmits the image sampling data S 11  and the depth sampling data S 21  according to the 3D image data format in  FIG. 9 . The 3D image data format in  FIG. 9  has a data bandwidth the same as a data bandwidth of the 2D image data format YUV422 in  FIG. 4 . The luma components Y 1  to Y n  are outputted via a first channel; and the first color component U 1 , the image depth data D 2 , the second color component V 1 , the image depth data D 4 , the first color component U 5 , the image depth data D 6 , the second color component V 5 , . . . , the first color component U n−3 , the image depth data D n−2 , and the second color component V n−3  are outputted via a second channel. 
         [0045]    As described, in the second embodiment, 3D image transmission can be completed through the data bandwidth the same as the data bandwidth of the 2D image data format YUV422. Therefore, the second embodiment can transmit the 3D image without requiring an additional data bandwidth. Further, the 2D image data and the image depth data can be simultaneously transmitted, and so no additional frame buffer is required to further reduce production costs. 
       Third Embodiment 
       [0046]    Referring to  FIGS. 10 and 11 ,  FIG. 10  shows a schematic diagram of a 10-bit 2D image format RGB444;  FIG. 11  shows a schematic diagram of a bit transmission format defined by a low-voltage differential signaling (LVDS) image transmission format. When an image transmission interface transmits a 2D image data via a 10-bit LVDS image transmission interface, the 2D image data can be transmitted according to the 10-bit 2D image data format RGB444 in  FIG. 10 . 
         [0047]    In  FIG. 10 , red components R 1 [9:0] to R n [9:0], green components G 1 [9:0] to G n [9:0], and blue components B 1 [9:0] to B n [9:0] are 10-bit. A 1 st  pixel data includes the red component R 1 [9:0], the green component G 1 [9:0] and the blue component B 1 [9:0], a next pixel data includes the red component R 2 [9:0], the green component G 2 [9:0] and the blue component B 2 [9:0], and so forth. That is, an n th  pixel data includes a red component R n [9:0], a green component G n [9:0] and a blue component B n [9:0]. The pixel data are transmitted according to a bit transmission format in  FIG. 11 . 
         [0048]    The bit transmission format defined by the LVDS image transmission interface is as depicted in  FIG. 11 . The LVDS image transmission interface defines a reserved bit RSV 0 , a reserved bit RSV 1 , a data enable bit DEN, a vertical synchronization bit VS, a horizontal synchronization bit HS, data bits r 0  to r 9 , data bits g 0  to g 9 , and data bits b 0  to b 9 . The data bits r 0  to r 9 , the data bits g 0  to g 9 , and the data bits b 0  to b 9  are for respectively transmitting the red component, the green component and the blue component in the 2D image data. 
         [0049]    The data bit g 4  and the data bits r 4  to r 9  are transmitted via a channel A, and the data bits b 4  to b 5  and the data bits g 5  to g 9  are transmitted via a channel B. The data enable bit DEN, the vertical synchronization bit VS, the horizontal synchronization bit HS and the data bits b 6  to b 9  are transmitted via a channel C. The reserved bit RSV 0 , the data bits r 2  to r 3 , the data bits g 2  to g 3  and the data bits b 2  to b 3  are transmitted via a channel D. The reserved bit RSV 1 , the data bits r 0  to r 1 , the data bits g 0  to g 1  and the data bits b 0  to b 1  are transmitted via a channel E. 
         [0050]    Referring to  FIGS. 12 ,  13  and  18 ,  FIG. 12  shows a flowchart of a 3D image transmitting method according to the third embodiment of the present invention;  FIG. 13  shows a schematic diagram of a 3D image data format according to the third embodiment of the present invention;  FIG. 18  shows a schematic diagram of a 3D image transmitting apparatus according to the third embodiment of the present invention. A main difference between a 3D image transmitting apparatus  9  and the 3D image transmitting apparatus  8  is that the down-sampling circuit  72  in the 3D image transmitting apparatus  9  does not down-sample the 2D image data S 1 . The data reconstructing circuit  73  transmits the 2D image data S 1  and the image depth data S 21  according to a 3D image data format in  FIG. 13 . The 3D image transmitting apparatus  9  and the 3D image transmitting method are applied to the foregoing LVDS image transmission interface. 
         [0051]    The method includes the following steps. In Step  51 , the receiving circuit  71  receives the 2D image data S 1  and the image depth data S 2 . In the third embodiment, the image depth data S 2  in 8-bit is taken as an example. 
         [0052]    In Step  52 , the down-sampling circuit  72  down-samples the image depth data S 2  to generate the depth sampling data S 21 . In the third embodiment, the depth sampling data S 21  is a pixel sampled from every four pixels of the image depth data S 2 , and so a data amount of the depth sampling data S 21  is one-fourth of a data amount of the image depth data S 2 . The depth sampling data S 21  includes the image depth data D 1 , D 3 , . . . , and D n−3 . 
         [0053]    In Step  53 , the data reconstructing circuit  73  transmits the 2D image data S 1  and the depth sampling data S 21  according to a 3D image data format in  FIG. 13 . The depth sampling data S 21  is transmitted via the reserved bit RSV 0  and the reserved bit RSV 1 . The 3D image data format in  FIG. 13  has a data bandwidth the same as a data bandwidth of the 2D of the 10-bit 2D image data format RGB444 in  FIG. 10 . 
         [0054]    For example, when transmitting the red component R 1 [9:0], the green component G 1 [9:0] and the blue component B 1 [9:0] of the 1 st  pixel data, the image depth data D 1 [7:6] is transmitted via the reserved bit RSV 0  and the reserved bit RSV 1 . When transmitting the red component R 2 [9:0], the green component G 2 [9:0] and the blue component B 2 [9:0] of the 2 nd  pixel data, the image depth data D 1 [5:4] is transmitted via the reserved bit RSV 0  and the reserved bit RSV 1 . When transmitting the red component R 3 [9:0], the green component G 3 [9:0] and the blue component B 3 [9:0] of the 3 rd  pixel data, the image depth data D 1 [3:2] is transmitted via the reserved bit RSV 0  and the reserved bit RSV 1 . When transmitting the red component R 4 [9:0], the green component G 4 [9:0] and the blue component B 4 [9:0] of the 4 th  pixel data, the image depth data D 1 [1:0] is transmitted via the reserved bit RSV 0  and the reserved bit RSV 1 . Thus, one complete image depth data is correspondingly transmitted when every four pixel data are transmitted. 
         [0055]    As described, in the third embodiment, 3D image transmission can be completed through the data bandwidth the same as the data bandwidth of the 10-bit 2D image data format RGB444. Therefore, the third embodiment can transmit the 3D image without requiring an additional data bandwidth. Further, the 2D image data and the image depth data can be simultaneously transmitted, and so no additional frame buffer is required to further reduce production costs. 
       Fourth Embodiment 
       [0056]    The description below is given with reference to  FIGS. 10 ,  11 ,  14 ,  15  and  19 .  FIG. 14  shows a flowchart of a 3D image transmitting method according to a fourth embodiment of the present invention;  FIG. 19  shows a schematic diagram of a 3D image transmitting apparatus according to the fourth embodiment of the present invention. A 3D image transmitting apparatus  2  includes a receiving circuit  71  and a data reconstructing circuit  73 . The 3D image transmitting apparatus  2  and the 3D image transmitting method are applied to the foregoing LVDS image transmitting interface. 
         [0057]    The method includes the following steps. In Step  61 , the receiving circuit  71  receives the 2D image data S 1  and the image depth data S 2 . In the fourth embodiment, an image transmitting interface is a 10-bit LVDS image transmission interface, and the 2D image data S 1  and the image depth data S 2  are both 8-bit. In other words, the red components R 1 [7:0] to R n [7:0], the green components G 1 [7:0] to G n [7:0], the blue components B 1 [7:0] to B n [7:0], and the image depth data D 1 [7:0] to D n [7:0] are 8-bit. 
         [0058]    In Step  62 , the data reconstructing circuit  73  transmits the 2D image data S 1  and the image depth data S 2  according to a 3D image data format in  FIG. 15 . The image depth data S 2  is transmitted via the reserved bit RSV 0 , the reserved bit RSV 1 , the data bits r 0  to r 1 , the data bits g 0  to g 1  and the data bits b 0  to b 1 . The 3D image data format in  FIG. 15  has a data bandwidth the same as a data bandwidth of the 10-bit 2D image data format RGB444 in FIG.  10 . 
         [0059]    For example, when transmitting the 1 st  pixel data, the image depth data D 1 [7:6] is transmitted via the reserved bit RSV 0  and the reserved bit RSV 1 , the image depth data D 1 [5:0] is transmitted the data bits r 0  to r 1 , the data bits g 0  to g 1  and the data bits b 0  to b 1 . Accordingly, when transmitting the n th  pixel data, the image depth data D n [7:6] are transmitted via the reserved bit RSV 0  and the reserved bit RSV 1 , and the image depth data D n [5:0] is transmitted the data bits r 0  to r 1 , the data bits g 0  to g 1  and the data bits b 0  to b 1 . 
         [0060]    As described, in the third embodiment, 3D image transmission can be completed through the data bandwidth the same as the data bandwidth of the image data format. Therefore, the third embodiment can transmit the 3D image without requiring an additional data bandwidth. Further, the 2D image data and the image depth data can be simultaneously transmitted, and so no additional frame buffer is required to further reduce production costs. 
         [0061]    While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.