Abstract:
The present disclosure relates to the field of display technology, and provides a video image mosaic system and a video image mosaic method. The video image mosaic system comprises an image signal source, an FPGA at least including image receivers, image scalars and image transmitters, and a DDR. The image signal source is connected to the image receivers, the DDR is connected to the image receivers and the image scalars, and the image scalars are connected to the image transmitters respectively.

Description:
CROSS REFERENCE OF RELATED APPLICATION 
       [0001]    The present application claims a priority of the Chinese patent application No. 201510203315.0 filed on Apr. 27, 2015, the disclosure of which is incorporated herein by reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    The present disclosure relates to the field of display technology, and in particular to a video image mosaic system and a video image mosaic method. 
       BACKGROUND 
       [0003]    As a hot topic in the area of video applications, video image mosaic technology may be widely used in various fields such as panoramic image generation, and application of robot with binocular vision. The image mosaic technology refers to mosaicking two or more images with an overlapping region by a video image mosaic system, so as to obtain an image with a broader vision. 
         [0004]    In the related art, the video image mosaic system mainly includes an image signal source, a Field Programmable Gate Array (FPGA) and a Double Data Rate SDRAM (DDR). The FPGA includes an image receiver, an image scalar and an image transmitter. As illustrated in  FIG. 1 , the image signal source is connected to the image receiver, the image scalar is connected to both the image receiver and the DDR, and the DDR is connected to the image transmitter. For example, a process for obtaining a 6K3K mosaic image by mosaicking a 2K1K image or a 4K2K image includes: scaling the 2K1K image or the 4K2K image by the scalar to obtain a 6K3K image; segmenting the 6K3K image by the DDR to obtain multiple sub-images and transmitting the multiple sub-images to the image receiver; and outputting the multiple sub-images synchronously to mosaic the video images and obtain the 6K3K mosaic image. 
         [0005]    The inventor finds that there is at least the following problem in the related art. 
         [0006]    In the related art, the image scalar is connected to the image receiver, and the DDR is connected to the image transmitter; i.e., the images of different specifications are transmitted firstly through the scalar and then through the DDR. As a result, a considerably large DDR bandwidth is consumed by the scaling and segmenting steps. 
       SUMMARY 
       [0007]    An object of the present disclosure is to provide a video image mosaic system and a video image mosaic method, so as to overcome the above-mentioned drawback. 
         [0008]    In one aspect, the present disclosure provides in some embodiments a video image mosaic system, including an image signal source, a Field Programmable Gate Array (FPGA) at least including image receivers, image scalars and image transmitters, and a Double Data Rate SDRAM (DDR). The image signal source is connected to the image receivers, the DDR is connected to the image receivers and the image scalars, and the image scalars are connected to the image transmitters respectively. 
         [0009]    Alternatively, the image receivers include a High Definition Multimedia Interface (HDMI) receiver and a Low-Voltage Differential Signaling (LVDS) receiver. When an image of a first specification is outputted by the image signal source, the image signal source is connected to the HDMI receiver, and when an image of a second specification is outputted by the image signal source, the image signal source is connected to the LVDS receiver through a System On Chip (SOC). 
         [0010]    Alternatively, the FPGA includes image enhancement processors, which are connected to the image scalars and the image transmitters and configured to enhance sub-images. 
         [0011]    Alternatively, the FPGA includes a selector which is connected to the image receivers and the DDR, and configured to select an image to be outputted to the DDR among images of different specifications outputted by the image signal source. 
         [0012]    Alternatively, the number of the image scalars is equal to the number of the sub-images obtained by segmenting the image through the DDR. 
         [0013]    Alternatively, the number of the image enhancement processors is equal to the number of the sub-images obtained by segmenting the image through the DDR. 
         [0014]    Alternatively, the number of the image transmitters is equal to the number of the sub-images obtained by segmenting the image through the DDR. 
         [0015]    Alternatively, the system includes a Write DDR Memory Access (WDMA) and a system bus. The WDMA is connected to the selector and the system bus, and the system bus is connected to the DDR. 
         [0016]    Alternatively, the system includes Read DDR Memory Accesses (RDMAs). The RDMAs are connected to the image scalars and the system bus, and the system bus is connected to the DDR. 
         [0017]    In another aspect, the present disclosure provides in some embodiments a video image mosaic method for use in the above-mentioned video image mosaic system. The method includes steps of: receiving, by one of image receivers, an image from an image signal source; segmenting, by a DDR, the image into a predetermined number of first sub-images; scaling, by image scalars, the predetermined number of the first sub-images synchronously to obtain the predetermined number of second sub-images with a specification identical to the first sub-images; and outputting, by image transmitters, the predetermined number of the second sub-images. 
         [0018]    Alternatively, subsequent to the step of scaling, by the image scalars, the predetermined number of the first sub-images synchronously, the method further includes enhancing, by image enhancement processors, the predetermined number of the second sub-images synchronously to obtain the predetermined number of third sub-images, and outputting, by the image transmitters, the predetermined number of the third sub-images. 
         [0019]    Alternatively, prior to the step of receiving the image by one of the image receivers, the method further includes performing, by a SOC, differential processing on an image of a second specification to obtain an image of the second specification in a LVDS format, when the image of the second specification is outputted by the image signal source. 
         [0020]    Alternatively, the step of segmenting, by the DDR, the image into the predetermined number of the first sub-images includes segmenting, by the DDR, the image into the predetermined number of the first sub-images of an identical size. 
         [0021]    According to the embodiments of the present disclosure, the DDR is connected to the image receivers, and the image scalars are connected to the image transmitters respectively, i.e., the images of different specifications are transmitted firstly through the DDR and then through the image scalars, so the image is firstly segmented and then scaled. As a result, as compared with the related art, it is able to reduce the DDR bandwidth consumption while ensuring the image quality. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    In order to illustrate the technical solutions of the present disclosure or the prior art in a clearer manner, the drawings desired for the embodiments will be described briefly hereinafter. Obviously, the following drawings merely relate to some embodiments of the present disclosure, and based on these drawings, a person skilled in the art may obtain the other drawings without any creative effort. 
           [0023]      FIG. 1  is a schematic view showing an existing video image mosaic system; 
           [0024]      FIG. 2  is a schematic view showing a video image mosaic system according to one embodiment of the present disclosure; and 
           [0025]      FIG. 3  is a flow chart of a video image mosaic method according to one embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    In order to make the objects, the technical solutions and the advantages of the present disclosure more apparent, some technical solutions of the present disclosure will be described hereinafter in a clear and complete manner in conjunction with the drawings and embodiments. Obviously, the following embodiments are merely a part of, rather than all of, the embodiments of the present disclosure, and based on these embodiments, a person skilled in the art may obtain the other embodiments, which also fall within the scope of the present disclosure. 
         [0027]    Unless otherwise defined, any technical or scientific term used herein shall have the common meaning understood by a person of ordinary skills. Such words as “first” and “second” used in the specification and claims are merely used to differentiate different components rather than to represent any order, number or importance. Similarly, such words as “one” or “a” are merely used to represent the existence of at least one member, rather than to limit the number thereof. Such words as “connect” or “connected to” may include electrical connection, direct or indirect, rather than to be limited to physical or mechanical connection. Such words as “on”, “under”, “left” and “right” are merely used to represent relative position relationship, and when an absolute position of the object is changed, the relative position relationship will be changed too. 
         [0028]    Referring to  FIG. 2 , which is a schematic view showing a video image mosaic system according to one embodiment of the present disclosure, the video image mosaic system includes an image signal source  21 , a FPGA  22  and a DDR  23 . The FPGA  22  at least includes image receivers  221 , image scalars  222  and image transmitters  223 . 
         [0029]    The image signal source  21  is connected to the image receivers  221 , the DDR  23  is connected to the image receivers  221  and the image scalars  222 , and the image scalars  222  are connected to the image transmitters  223  respectively. 
         [0030]    In some embodiments of the present disclosure, the image signal source  21  may output video images of different specifications. For example, the image signal source  21  may output 4K2K images when the image signal source  21  includes a HDMI 1.4A signal source, and the image signal source  21  may output 2K1K images when the image signal source  21  includes a HDMI/VGA signal source. Of course, the image signal source is not particularly defined herein. 
         [0031]    As illustrated in  FIG. 2 , the image receivers  221  include a HDMI receiver  2211  and a LVDS receiver  2212 . When the image signal source  21  outputs an image of a first specification (for example, a 4K2K image), the image signal source  21  is connected to the HDMI receiver  2211 , and when the image signal source  21  outputs an image of a second specification (for example, a 2K1K image), the image signal source  21  is connected to the LVDS receiver  2212  through a SOC  24 . The SOC may perform differential processing on the image outputted by the image signal source. 
         [0032]    Different from the related art, in the embodiments of the present disclosure, the DDR  23  is connected to the image receivers  221  and the image scalars  222 , i.e. an input end of the DDR  23  is connected to output ends of the image receivers  221 , and an output end of the DDR  23  is connected to input ends of the image scalars  222 , so that the image is firstly segmented and then scaled. As a result, it is able to reduce the bandwidth consumption of the DDR  23 . 
         [0033]    It should be appreciated that, both the number of the image scalars  222  and the number of the image transmitters  223  are equal to the number of sub-images obtained by segmenting the image through the DDR  23 . In other words, when the DDR  23  segments each video image into 3*3 (i.e., 9) sub-images, both the number of the image scalars  222  and the number of the image transmitters  223  are 9 too. Each image scalar  222  is configured to scale one of the 9 sub-images, while each image transmitter  223  is configured to output one of the 9 sub-images synchronously. 
         [0034]    Furthermore, the DDR  23  may segment the image into the sub-images of an identical size. For example, the DDR  23  may segment a 4K2K image into 3*3 (i.e., 9) sub-images, and each of the sub-images is of a size of 4/9K2/9K. The sub-images are scaled by the image scalars  222  separately and synchronously. For example, each 4/9K2/9K sub-image is scaled into a 2K1K sub-image by the image scalar  222 . Of course, a magnification factor is not particularly defined herein. 
         [0035]    As illustrated in  FIG. 2 , the FPGA  22  includes the image enhancement processors  224 . The image enhancement processors  224  are connected to the image scalars  222  and the image transmitters  223 , and configured to enhance the sub-images. 
         [0036]    It should be appreciated that, the number of the image enhancement processors  224  is also equal to the number of the sub-images obtained by segmenting the image through the DDR  23 . In other words, when the DDR  23  segments each video image into 3*3 (i.e., 9) sub-images, the number of the image enhancement processors  224  is 9 too, and each image enhancement processor  224  is configured to enhance one of the 9 sub-images. An input end of each image enhancement processor  224  is connected to an output end of one of the image scalars, and an output end of each image enhancement processor  224  is connected to one of the image transmitters  223 . 
         [0037]    The image enhancement process aims to enhance useful information in the image. The image enhancement process may be a process of distortion, so as to improve a visual effect of the image, purposefully emphasize entire or partial characteristics of the given image in view of an application scene, convert a blurred image into a clear one or emphasize some characteristics of interest, highlight a difference between different objects in the image, and suppress the characteristics out of interest. As a result, it is able to improve the image quality, provide more information, improve interpretation and identification of the image, and satisfy the requirement of particular analyses. 
         [0038]    As illustrated in  FIG. 2 , the FPGA  22  includes a selector  225 , a WDMA  226 , a system bus  227  and RDMAs  228 . The image receivers  221  are connected to the DDR  23  through the selector  225 , the WDMA  226  and the system bus  227 . The WDMA  226  is connected to the selector  225  and the system bus  227 , and the system bus  227  is connected to the DDR  23 . The selector  225  is configured to select the image to be outputted to DDR  23  among the images of different specifications outputted by the image signal source. The RDMAs  228  are connected to the image scalars  222  and the system bus  227 , and the system bus  227  is connected to the DDR  23 . 
         [0039]    The number of the RDMAs  228  is equal to the number of the sub-images obtained by segmenting the image through the DDR  23 . In other words, when the DDR  23  segments each video image into 3*3 (i.e., 9) sub-images, the number of the RDMAs  228  is 9 too. The sub-image outputted by an output end of each RDMA  228  is inputted to one of the image scalar  222 . 
         [0040]    Furthermore, after being enhanced by the image enhancement processors  224 , the enhanced sub-images are buffered in line buffers  229 , and then transmitted to the image transmitters (HDMI TX). All of the sub-images are outputted synchronously, so as to obtain the mosaic video image. For example, for the 4K2K image, when the DDR  23  segments the 4K2K image into 9 sub-images of an identical size and the sub-image are scaled to 2K1K images synchronously, a 6K3K image may be obtained by outputting the 9 sub-images synchronously. At this time, a bandwidth of 4K2K is consumed, and as compared with the related art where a bandwidth of 6K3K is consumed, it is able to remarkably reduce the bandwidth consumption. 
         [0041]    According to the system in the embodiments of the present disclosure, the DDR is connected to the image receivers, and the image scalars are connected to the image transmitters respectively, i.e., the images of different specifications are transmitted firstly through the DDR and then through the image scalars, so the image is firstly segmented and then scaled. As a result, as compared with the related art, it is able to reduce the DDR bandwidth consumption while ensuring the image quality. 
         [0042]    Referring to  FIG. 3 , which is a flow chart of a video image mosaic method according to one embodiment of the present disclosure, the method includes the following steps. 
         [0043]    Step  301 : receiving, by one of image receivers, an image from an image signal source. 
         [0044]    In some embodiments of the present disclosure, prior to receiving the image by the image receiver, the method further includes performing, by a SOC, differential processing on an image of a second specification to obtain an image of the second specification in a LVDS format, when the image of the second specification is outputted by the image signal source. 
         [0045]    Step  302 : segmenting, by a DDR, the image into a predetermined number of first sub-images. 
         [0046]    The predetermined number may be 4, 9, 16 and etc., and the number of the sub-images is not particularly defined herein. 
         [0047]    In some embodiments, the step of segmenting, by the DDR, the image into a predetermined number of the first sub-images include segmenting, by the DDR, the image into the predetermined number of the first sub-images of an identical size. 
         [0048]    Step  303 : scaling, by image scalars, the predetermined number of the first sub-images synchronously to obtain the predetermined number of second sub-images with a specification identical to the first sub-images. 
         [0049]    Step  304 : enhancing, by image enhancement processors, the predetermined number of the second sub-images synchronously to obtain the predetermined number of third sub-images. 
         [0050]    Step  305 : outputting, by image transmitters, the predetermined number of the third sub-images. 
         [0051]    According to the method in the embodiments of the present disclosure, the image is firstly segmented and then scaled. As a result, as compared with the related art, it is able to reduce the DDR bandwidth consumption while ensuring the image quality. 
         [0052]    It should be appreciated that, all or a part of the steps in the above-mentioned embodiments may be implemented by hardware, or by programs which are used to instruct relevant hardware. The programs may be stored in a computer-readable storage medium, such as a Read Only Memory (ROM), a magnetic disc or an optical disc. 
         [0053]    The above are merely the preferred embodiments of the present disclosure. A person skilled in the art may make further modifications and improvements without departing from the principle of the present disclosure, and these modifications and improvements shall also fall within the scope of the present disclosure.