Video signal transmission device, video signal relay device, and video signal transmission / reception system

Abstract

To provide a video signal transmission device, a video signal relay device, and a video signal transmission / reception system, in which image quality degradation is suppressed when a video signal acquired by an imaging element is analog-transmitted.SOLUTION: A video signal transmission device includes: a YC conversion part that receives RAW data output from an imaging element by performing an imaging, converts the RAW data into YC data including luminance data, first color difference data, and second color difference data, and outputs the YC data; a digital-analog conversion part that converts the YC data output from the YC conversion part into an analog signal, and outputs the analog signal; and an analog transmission part that transmits the analog signal converted by the digital-analog conversion part to the outside.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a video signal transmission device, a video signal relay device, and a video signal transmission / reception system.

Background Art

[0002] Patent Document 1 describes an imaging device that digitally transmits RAW data output from an imaging element to an external device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is a demand to transmit a video signal acquired by an imaging element to an external device by inexpensive analog transmission as compared with digital transmission.

[0005] However, in recent years, the resolution of imaging elements has been increasing and the data volume of video signals has been increasing. Therefore, there is a problem that it has become difficult to analog-transmit a video signal without degrading the image quality of the video signal acquired by the imaging element.

[0006] In view of the above circumstances, an object of the present disclosure is to provide a video signal transmission device, a video signal relay device, and a video signal transmission / reception system that suppress image quality degradation when analog-transmitting a video signal acquired by an imaging element.

Means for Solving the Problems

[0007] The video signal transmission device of the present disclosure receives RAW data output from an image sensor by performing imaging, and converts the RAW data into YC data composed of luminance data, first color difference data, and second color difference data and outputs the converted data. It includes a YC conversion unit, a digital-to-analog conversion unit that converts the YC data output from the YC conversion unit into an analog signal and outputs the converted signal, and an analog transmission unit that transmits the analog signal converted by the digital-to-analog conversion unit to the outside.

[0008] The video signal relay device of the present disclosure includes a receiving unit that receives an analog signal transmitted from the video signal transmission device of the present disclosure, an analog-to-digital conversion unit that converts the analog signal received by the receiving unit into YC data and outputs the converted data, and a RAW conversion unit that converts the YC data output from the analog-to-digital conversion unit into RAW data and outputs the converted data.

[0009] The video signal transmission / reception system of the present disclosure includes a camera including the image sensor, the video signal transmission device of the present disclosure, the video signal relay device of the present disclosure, and a display device that displays an image based on the signal output from the video signal relay device.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0011] [First Embodiment] Next, embodiments of the present disclosure will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a video signal transmission / reception system 1 according to a first embodiment of the present disclosure. FIG. 2 is a diagram showing a schematic configuration of an image pickup device.

[0012] As shown in FIG. 1, the video signal transmission / reception system 1 of the first embodiment includes a video signal transmission device 10, a video signal relay device 20, a camera 30, and a display device 40 that displays a video based on the signal output from the video signal relay device 20.

[0013] The camera 30 includes an image sensor 31 and an imaging lens (not shown) and the like. The image sensor 31 outputs RAW data generated by performing imaging. As shown in FIG. 2, the image sensor 31 of the present embodiment has three colors of pixels, namely, red (R) pixels, green (G) pixels, and blue (B) pixels, arranged in a Bayer array. Hereinafter, the red pixel may be described as pixel R, the green pixel as pixel G, and the blue pixel as pixel B.

[0014] One period in either the horizontal or vertical direction of this Bayer array is 2 pixels, and one period in the other direction is 2 pixels. The first row in the horizontal direction consists of pixel G and pixel R, and the second row in the horizontal direction consists of pixel B and pixel G, forming a unit for one period of the Bayer array. The image sensor 31 has a Bayer array in which these units are continuously arranged in the vertical and horizontal directions.

[0015] Note that there is no particular limitation on the data amount of each pixel, and it may be any data amount according to the specifications of the image sensor 31. In the present embodiment, as an example, the data amount of each pixel is 8 bits.

[0016] Returning to FIG. 1, the video signal transmission device 10 includes a YC conversion unit 11, a DAC (Digital to Analog Converter) 12, and a transmission unit 13. Note that the DAC 12 is an example of the digital-to-analog conversion unit in the technology of the present disclosure.

[0017] The YC conversion unit 11 converts the RAW data output from the image sensor 31 into YC data and outputs it. There is no particular limitation on the mode of YC conversion by the YC conversion unit 11, and it may be any mode such as YC444 conversion, YC422 conversion, or YC411 conversion. In the present embodiment, as an example, the YC conversion unit 11 performs YC422 conversion.

[0018] The DAC 12 converts the YC data output from the YC conversion unit 11 into an analog signal and outputs it. The transmission unit 13 transmits the analog signal converted by the DAC 12.

[0019] The video signal relay device 20 includes a receiving unit 21, an ADC (Analog to Digital Converter) 22, a RAW conversion unit 23, and an RGB conversion unit 24. The ADC 22 is an example of the analog-to-digital conversion unit in the technology of the present disclosure.

[0020] The receiving unit 21 receives the analog signal transmitted from the video signal transmission device 10. The ADC 22 converts the analog signal received by the receiving unit 21 into digital data and outputs it. The RAW conversion unit 23 converts the digital data output from the ADC 22 into RAW data by performing a process reverse to that of the YC conversion unit 11 of the video signal transmission device 10 and outputs it. The RGB conversion unit 24 performs RGB conversion on the RAW data output from the RAW conversion unit 23 to obtain RGB data.

[0021] Next, the processing at the time of analog signal transmission in the video signal transmission device 10 of the video signal transmission and reception system 1 of the present embodiment will be described. FIG. 3 is a diagram showing the signal formats in each part of the video signal transmission device 10 and the video signal relay device 20. FIG. 18 is a diagram showing the hardware configuration of the YC conversion unit 11. FIGS. 19, 20, and 21 are time charts for explaining the processing in the YC conversion unit 11. FIG. 22 is a partially enlarged view of the time chart shown in FIG. 21. FIG. 4 is a diagram showing the functional configuration of the YC conversion unit 11 in the video signal transmission device 10 of the present embodiment. FIG. 5 is a diagram for explaining the YC conversion process. FIG. 6 is a diagram for explaining the RAW conversion process. FIG. 23 is a diagram showing the hardware configuration of the RAW conversion unit 23. FIGS. 24, 25, and 26 are time charts for explaining the processing in the RAW conversion unit 23.

[0022] As shown in FIG. 3, the video signal transmission device 10 of the present embodiment converts the RAW data output from the imaging element 31 into YC data by the YC conversion unit 11, converts the converted YC data into an analog signal by the DAC 12, and transmits it as an analog signal from the transmission unit 13.

[0023] The data amount for one pixel in the RAW data output from the imaging element 31 is 8 bits, and the data amount for one unit corresponding to one cycle of the Bayer array is 32 bits.

[0024] As shown in FIG. 4, the YC conversion unit 11 includes an arithmetic processing unit 11a. The YC conversion unit 11 is realized, for example, by the following hardware configuration.

[0025] As shown in FIG. 18, the YC conversion unit 11 includes a frequency division unit 70, a synchronization signal generation unit 71, an output timing generation unit 72, a memory 73, a memory write control unit 74, a memory read control unit 75, and a processor 76.

[0026] The frequency division unit 70 divides the RAW clock signal clk_raw corresponding to the RAW data raw input from the outside of the YC conversion unit 11 by a frequency of 1 / 2 to generate a YC clock signal clk_yc corresponding to the YC data.

[0027] Based on the vertical synchronization signal vs_raw, horizontal synchronization signal hs_raw, and display period signal de_raw of the RAW data raw input from the outside of the YC conversion unit 11 and the RAW clock signal clk_raw, the synchronization signal generation unit 71 generates an internal processing vertical synchronization signal vs_org and horizontal synchronization signal hs_org and outputs them to the output timing generation unit 72 and the memory write control unit 74.

[0028] Based on the vertical synchronization signal vs_org and horizontal synchronization signal hs_org, the output timing generation unit 72 generates a temporary vertical synchronization signal vs_yct and a temporary horizontal synchronization signal hs_yct of the YC data dy / dc / cr and outputs them to the memory read control unit 75 and the processor 76.

[0029] The memory 73 stores the RAW data raw input from the outside of the YC conversion unit 11.

[0030] The memory write control unit 74 controls the writing of the RAW data raw to the memory 73.

[0031] The memory read control unit 75 controls the reading of RAW data raw from the memory 73.

[0032] The processor 76 converts the RAW data raw into YC data dy / dc / cr and outputs it externally together with the vertical synchronization signal vs_yc, the horizontal synchronization signal hs_yc, and the display period signal de_yc of the YC data.

[0033] Next, the processing in the YC conversion unit 11 will be described.

[0034] First, as shown in FIG. 19, the synchronization signal generation unit 71 doubles the pulse width and the pulse period of the vertical synchronization signal vs_raw of the RAW data raw in synchronization with the RAW clock signal clk_raw to generate a vertical synchronization signal vs_org. Further, the synchronization signal generation unit 71 doubles the pulse period of the horizontal synchronization signal hs_raw of the RAW data raw in synchronization with the RAW clock signal clk_raw to generate a horizontal synchronization signal hs_org.

[0035] Next, the output timing generation unit 72 adjusts the timing of the vertical synchronization signal vs_org in synchronization with the YC clock signal clk_yc to generate a temporary vertical synchronization signal vs_yct of the YC data. Further, the output timing generation unit 72 adjusts the timing of the horizontal synchronization signal hs_org in synchronization with the YC clock signal clk_yc and doubles the pulse width to generate a temporary horizontal synchronization signal hs_yct of the YC data.

[0036] Next, as shown in FIG. 20, the memory write control unit 74 writes the RAW data raw into the memory 73 in synchronization with the RAW clock signal clk_raw.

[0037] Specifically, in the RAW data raw, as data lines in the horizontal direction, the data lines of GR and the data lines of BG are alternately arranged. Further, the memory 73 has a recording area of four lines of mem1, mem2, mem3, and mem4.

[0038] The memory write control unit 74 writes the data line of the first GR to mem1, the data line of the second BG to mem2, the data line of the third GR to mem3, and the data line of the fourth BG to mem4 for each of the four horizontal data lines.

[0039] The data line of GR written to mem1, the data line of BG written to mem2, the data line of GR written to mem3, and the data line of BG written to mem4 are held until the writing of the next four data lines is started.

[0040] Next, the memory write control unit 74 reads the RAW data raw from the memory 73 in synchronization with the YC clock signal clk_yc.

[0041] Specifically, the memory write control unit 74 combines the data line of GR written to mem1 and the data line of BG written to mem2, and reads them from the memory 73 as RAW data raw1 and raw2 for two horizontal lines. Also, the memory write control unit 74 combines the data line of GR written to mem3 and the data line of BG written to mem4, and reads them from the memory 73 as RAW data raw1 and raw2 for two horizontal lines.

[0042] Next, as shown in FIG. 21, the processor 76 converts the RAW data raw1 and raw2 for two horizontal lines into YC data dy / dc / cr in synchronization with the YC clock signal clk_yc.

[0043] Specifically, as shown in FIG. 22, the processor 76 converts each unit of data for one cycle of the Bayer array consisting of GRBG in the RAW data raw1 and raw2 for two horizontal lines into YC data dy / dc / cr. The details of the conversion process will be described in detail later.

[0044] The processor 76 outputs the converted YC data dy / dc / cr to the outside together with the vertical synchronization signal vs_yc, the horizontal synchronization signal hs_yc, and the display period signal de_yc of this YC data dy / dc / cr.

[0045] As described above, RAW data is input to the YC conversion unit 11, and the RAW data input in the arithmetic processing unit 11a is YC422-converted to generate YC data, which is separated into Y data (i.e., luminance data) and CbCr data (i.e., color difference data) and output.

[0046] Specifically, as shown in FIG. 5, the YC conversion unit 11 converts the RAW data into YC data by YC422 conversion for each unit composed of 4 pixels of 2 pixels in the horizontal direction × 2 pixels in the vertical direction of the RAW data, and in one of the two rows in the horizontal direction, the Y data of the first pixel and the Y data of the second pixel in order from the head, and in the other row of the two rows in the horizontal direction, the Cb data and the Cr data common to the first pixel and the second pixel are obtained as YC data for two pixels arranged in the horizontal direction composed of four signals.

[0047] The data amount for one pixel in the YC data converted from the RAW data for one unit is 16 bits, and the data amount for two pixels corresponding to one unit of the Bayer array is 32 bits.

[0048] There is no particular limitation on the method of YC422 conversion at this time. For example, any method such as various existing conversion formulas or the following simple conversion formula may be used. In this embodiment, as an example, YC422 conversion is performed using the following simple conversion formula. Y0 = G0 Y1 = G1 G = (G0 + G1) / 2 Y = (5G + 2R + B) / 8 Cb = B - Y Cr = R - Y

[0049] As described above, since the data amount of 4 pixels corresponding to one unit of the Bayer array in the RAW data is 32 bits, and the data amount of 2 pixels corresponding to one unit of the Bayer array in the YC data is 32 bits, the data amount does not change before and after converting the RAW data to YC422. That is, no data degradation occurs due to the YC422 conversion in the YC conversion unit 11.

[0050] Returning to FIG. 3, the video signal relay device 20 of the present embodiment receives the analog signal transmitted from the video signal transmission device 10 by the receiving unit 21, converts the received analog signal into digital data by the ADC 22, converts the converted digital data into RAW data by the RAW conversion unit 23, and converts the converted RAW data by the RGB conversion unit 24 to obtain RGB data.

[0051] The RAW conversion unit 23 converts the digital data output from the ADC 22 into RAW data by performing a process reverse to that of the YC conversion unit 11 of the video signal transmission device 10. The RAW conversion unit 23 is realized, for example, by the following hardware configuration.

[0052] As shown in FIG. 23, the RAW conversion unit 23 includes a frequency division unit 80, a processor 81, a memory 82, a memory write control unit 83, a memory read control unit 84, and an output timing generation unit 85.

[0053] The frequency division unit 80 divides the RAW clock signal clk_raw corresponding to the RAW data raw input from the outside of the RAW conversion unit 23 by a frequency of 1 / 2 to generate a YC clock signal clk_yc corresponding to the YC data.

[0054] The processor 81 converts the YC data dy / dc / cr into RAW data raw based on the YC data dy / dc / cr, the vertical synchronization signal vs_yc, the horizontal synchronization signal hs_yc, and the display period signal de_yc of the YC data dy / dc / cr, and the YC clock signal clk_yc, and generates a temporary vertical synchronization signal vs_rawt and a temporary horizontal synchronization signal hs_rawt of the RAW data raw, and outputs them to the memory write control unit 83 and the output timing generation unit 85.

[0055] The memory 82 stores the RAW data raw input from the processor 81.

[0056] The memory write control unit 83 controls the writing of the RAW data raw to the memory 82.

[0057] The memory read control unit 84 controls the reading of the RAW data raw from the memory 82.

[0058] The output timing generation unit 85 generates a vertical synchronization signal vs_raw and a horizontal synchronization signal hs_raw of the RAW data raw based on the temporary vertical synchronization signal vs_rawt and the temporary horizontal synchronization signal hs_rawt of the RAW data raw, and outputs them externally.

[0059] Next, the processing in the RAW conversion unit 23 will be described.

[0060] First, as shown in FIG. 24, the processor 81 converts the YC data dy / dc / cr into two lines of RAW data raw1 and raw2 in the horizontal direction in synchronization with the YC clock signal clk_yc. The details of the conversion process will be described in detail later.

[0061] The processor 81 generates a temporary vertical synchronization signal vs_rawt, a temporary horizontal synchronization signal hs_rawt, and a temporary display period signal de_rawt of the two converted lines of RAW data raw1 and raw2 in the horizontal direction, and outputs them together with the RAW data raw1 and raw2 to the memory write control unit 83 and the output timing generation unit 85.

[0062] Next, as shown in FIG. 25, the output timing generation unit 85 adjusts the timing of the temporary vertical synchronization signal vs_rawt in synchronization with the RAW clock signal clk_raw, and generates the vertical synchronization signal vs_raw of the RAW data raw by reducing the pulse width and the pulse period to 1 / 2. Further, the output timing generation unit 85 adjusts the timing of the temporary horizontal synchronization signal hs_rawt in synchronization with the RAW clock signal clk_raw, and generates the horizontal synchronization signal hs_raw of the RAW data raw by reducing the pulse width and the pulse period to 1 / 2.

[0063] Next, as shown in FIG. 26, the memory write control unit 83 writes the RAW data raw1 and raw2 for two lines in the horizontal direction into the memory 82 in synchronization with the YC clock signal clk_yc.

[0064] Specifically, the memory 82 has a recording area of four lines of mem1, mem2, mem3, and mem4.

[0065] For each combination of two data in the RAW data raw1 and raw2 for two lines in the horizontal direction, the memory write control unit 83 writes the GR data line of the first data combination into mem1, the BG data line of the first data combination into mem2, the GR data line of the second data combination into mem3, and the BG data line of the second data combination into mem4.

[0066] The GR data line written into mem1, the BG data line written into mem2, the GR data line written into mem3, and the BG data line written into mem4 are held until the writing of the next two data combinations is started.

[0067] Next, the memory write control unit 84 reads out the RAW data raw1 and raw2 for two lines in the horizontal direction from the memory 82 in synchronization with the RAW clock signal clk_raw.

[0068] Specifically, the memory write control unit 84 sequentially reads out the data lines of GR written to mem1 and the data lines of BG written to mem2, and converts them into RAW data raw for one horizontal line. Further, the memory write control unit 84 sequentially reads out the data lines of GR written to mem3 and the data lines of BG written to mem4, and converts them into RAW data raw for one horizontal line.

[0069] As described above, the RAW conversion unit 23 generates RAW data for four pixels from YC data for two pixels for each unit.

[0070] In the present embodiment, since YC422 conversion is performed using the above simple conversion formula in the YC conversion unit 11 of the video signal transmission device 10, the RAW conversion unit 23 can convert the data into RAW data using the following simple inverse conversion formula. G0 = Y0 G1 = Y1 G = (G0 + G1) / 2 Y = (5G + 2R + B) / 8 B = Cb - Y R = Cr - Y

[0071] In the video signal relay device 20, the data amount for two pixels corresponding to one cycle of the Bayer array in the YC data is 32 bits, and the data amount for four pixels corresponding to one cycle of the Bayer array in the RAW data is 32 bits, which is the same as the data amount of each data in the video signal transmission device 10.

[0072] After acquiring the RAW data, the video signal relay device 20 performs RGB conversion on the RAW data by the RGB conversion unit 24 to acquire RGB data. In the video signal relay device 20 of the present embodiment, when the RGB conversion unit 24 performs RGB conversion on the RAW data, it also performs demosaicing processing. Demosaicing processing is a process of complementing pixels by referring to the color information of adjacent pixels for each pixel.

[0073] Specifically, for each pixel of the RAW data, RGB conversion interpolates data from surrounding pixels to generate 8-bit R data, G data, and B data respectively. As a result, in the RGB data, R data, G data, and B data are included within one pixel.

[0074] Therefore, the data amount for one pixel in the RGB data obtained by RGB conversion increases to 24 bits, and the data amount for four pixels corresponding to one unit of the Bayer array becomes 96 bits.

[0075] Next, the effects of the video signal transmission and reception system 1 of this embodiment will be described. FIG. 7(A) is a diagram showing the state of signal format change when transmitting a video signal from the video signal transmission device of the comparative example to the video signal relay device, and FIG. 7(B) is a diagram showing the state of signal format change when transmitting a video signal from the video signal transmission device 10 of this embodiment to the video signal relay device 20.

[0076] First, as a comparative example, a general video signal transmission and reception system that performs analog transmission will be described. As shown in FIG. 7(A), the video signal transmission device in the video signal transmission and reception system of the comparative example converts RAW data into RGB data by RGB conversion, converts the converted RGB data by YC422 conversion to generate YC data, and converts the generated YC data into an analog signal for analog transmission.

[0077] Here, the data amount for four pixels corresponding to one unit of the Bayer array in the RAW data is 32 bits, the data amount for four pixels corresponding to one unit of the Bayer array in the RGB data is 96 bits, and the data amount for four pixels corresponding to one unit of the Bayer array in the YC data is 64 bits.

[0078] Also, the video signal relay device in the video signal transmission and reception system of the comparative example digitally converts the received analog signal to obtain YC data, and converts the obtained YC data by RGB conversion to obtain RGB data.

[0079] Here, the data amount of 4 pixels corresponding to one unit of the Bayer array in YC data is 64 bits, and the data amount of 4 pixels corresponding to one unit of the Bayer array in RGB data is 96 bits.

[0080] Next, the video signal transmission / reception system 1 of the present embodiment will be described. As shown in FIG. 7(B), the video signal transmission device 10 in the video signal transmission / reception system 1 of the present embodiment converts RAW data into YC data by YC422 conversion, converts the generated YC data into an analog signal, and transmits it analogously.

[0081] Here, the data amount of 4 pixels corresponding to one unit of the Bayer array in RAW data is 32 bits, and as described above, the data amount of 2 pixels corresponding to one unit of the Bayer array in YC data is 32 bits.

[0082] Also, the video signal relay device 20 in the video signal transmission / reception system 1 of the present embodiment digitally converts the received analog signal to obtain YC data, performs RAW conversion on the obtained YC data to obtain RAW data, and converts the obtained RAW data into RGB data by RGB conversion.

[0083] Here, the data amount of 2 pixels corresponding to one unit of the Bayer array in YC data is 32 bits, the data amount of 4 pixels corresponding to one unit of the Bayer array in RAW data is 32 bits, and the data amount of 4 pixels corresponding to one unit of the Bayer array in RGB data is 96 bits.

[0084] When the video signal transmission / reception system 1 of the present embodiment is compared with the video signal transmission / reception system of the comparative example, the data amount of four pixels corresponding to one unit of the Bayer array in the RGB data finally obtained in the video signal relay device 20 in the video signal transmission / reception system 1 of the present embodiment is 96 bits, which is the same as the data amount of four pixels corresponding to one unit of the Bayer array in the RGB data finally obtained in the video signal relay device 20 in the video signal transmission / reception system of the comparative example.

[0085] However, the data amount of two pixels corresponding to one unit of the Bayer array in the YC data immediately before conversion to an analog signal in the video signal transmission device 10 in the video signal transmission / reception system 1 of the present embodiment is 32 bits, while the data amount of four pixels corresponding to one unit of the Bayer array in the YC data immediately before conversion to an analog signal in the video signal transmission device in the video signal transmission / reception system of the comparative example is 64 bits.

[0086] That is, according to the video signal transmission / reception system 1 of the present embodiment, when transmitting a video signal with the same data amount as that of the video signal transmission / reception system of the comparative example, the data amount of the analog signal transmitted from the video signal transmission device 10 can be reduced to half of that of the video signal transmission / reception system of the comparative example.

[0087] Therefore, according to the video signal transmission / reception system 1 of the present embodiment, when the video signal is transmitted analogously, it is possible to suppress image quality degradation during transmission and reception.

[0088] Further, according to the video signal transmission device 10 of the present embodiment, when the video signal is transmitted analogously, it is possible to suppress image quality degradation during transmission.

[0089] Also, according to the video signal relay device 20 of the present embodiment, when the video signal is transmitted analogously, it is possible to receive an analog signal with suppressed image quality degradation.

[0090] In the above-described embodiment, the YC conversion unit 11 of the video signal transmission device 10 was configured to perform YC422 conversion. However, as shown in FIG. 8, it may be configured to perform YC411 conversion.

[0091] Even when performing YC411 conversion, when transmitting a video signal with the same data amount as the video signal transmission / reception system of the comparative example, the data amount of the analog signal transmitted from the video signal transmission device 10 can be made half of the data amount of the video signal transmission / reception system of the comparative example.

[0092] Also, when performing YC411 conversion, although the image quality deteriorates compared to the case of performing YC422 conversion, the data amount of the analog signal transmitted from the video signal transmission device 10 can be reduced to 24 bits.

[0093] Also, as shown in FIG. 9, the YC conversion unit 11 of the video signal transmission device 10 may be configured to perform YC444 conversion.

[0094] Even when performing YC444 conversion, when transmitting a video signal with the same data amount as the video signal transmission / reception system of the comparative example, the data amount of the analog signal transmitted from the video signal transmission device 10 can be made half of the data amount of the video signal transmission / reception system of the comparative example.

[0095] Also, when performing YC444 conversion, although the data amount of the analog signal transmitted from the video signal transmission device 10 increases to 48 bits compared to the case of performing YC422 conversion, the image quality can be improved.

[0096] Also, the mode of YC conversion by the YC conversion unit 11 may be a mode other than the above-described YC444 conversion, YC422 conversion, or YC411 conversion.

[0097] [Second Embodiment] Next, the video signal transmission / reception system of the second embodiment will be described. In the video signal transmission / reception system of this embodiment, the processing of the YC conversion unit 11 of the video signal transmission device 10 and the processing of the RAW conversion unit 23 of the video signal relay device 20 are different from those of the video signal transmission / reception system 1 of the first embodiment. In the video signal transmission / reception system of this embodiment, the same components as those of the video signal transmission / reception system 1 of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted unless particularly necessary.

[0098] FIG. 10 is a diagram for explaining signal degradation during analog transmission of the video signal transmission / reception system of the first embodiment.

[0099] When the RAW data generated by the imaging device 31 with a Bayer array is YC-converted into YC data and analog-transmitted, as shown in FIG. 10, if the luminance difference between the luminance of a certain horizontal line in the RAW data and the luminance of the horizontal lines adjacent to the horizontal line in the vertical direction is large, abrupt changes in luminance will continuously occur in the YC data.

[0100] The reason for such a phenomenon is that the green pixels with a high contribution to luminance are arranged in a staggered pattern over two horizontal lines.

[0101] In the video signal transmission device 10, when such YC data with continuously occurring abrupt changes in luminance is converted into an analog signal by the DAC 12, signal degradation is likely to occur. Also, in the video signal relay device 20, when such an analog signal with continuously occurring abrupt changes in luminance is converted into digital data by the ADC 22 to obtain YC data, signal degradation is also likely to occur.

[0102] As a result, in the video signal relay device 20, when the YC data is RAW-converted to obtain RAW data, there may be problems such as blurring of edges and bleeding at the boundary portions.

[0103] The video signal transmission / reception system of this embodiment is configured to solve such problems. FIG. 11 is a diagram showing the functional configuration of the YC conversion unit 11 in the video signal transmission device 10 of this embodiment. The hardware configuration of the YC conversion unit 11 is the same as that of the first embodiment. In the first embodiment, the YC conversion unit 11 had only the function of the arithmetic processing unit 11a, but the processing of the data order rearrangement processing unit 11b, which is a newly added function in this embodiment, is performed by the processor 76.

[0104] In the YC conversion unit 11 of the video signal transmission device 10 of this embodiment, for each of a plurality of units arranged adjacent to each other in the horizontal direction, a first-pixel Y data group in which the first-pixel Y data of each of the plurality of units are arranged continuously, and a second-pixel Y data group in which the second-pixel Y data of each of the plurality of units are arranged continuously are separated into two Y data groups, and one of the Y data groups is sequentially output continuously as a horizontal signal. In this embodiment, as an example, the case where the above processing is performed for every two units arranged adjacent to each other in the horizontal direction will be described.

[0105] Specifically, as shown in FIG. 11, the YC conversion unit 11 includes an arithmetic processing unit 11a and a data order rearrangement processing unit 11b. RAW data is input to the YC conversion unit 11 every two horizontal lines.

[0106] The arithmetic processing unit 11a performs YC422 conversion on the input RAW data to generate YC data. Specifically, the YC conversion unit 11 converts the RAW data into YC data by YC422 conversion for each pixel block consisting of 8 pixels of 4 pixels in the horizontal direction × 2 pixels in the vertical direction, and in one of the two horizontal rows, the Y data of the first pixel (Y00 in the figure), the Y data of the second pixel (Y01 in the figure), the Y data of the third pixel (Y10 in the figure), and the Y data of the fourth pixel (Y11 in the figure) in order from the beginning, and in the other of the two horizontal rows, the Cb data (Cb0 in the figure) and Cr data (Cr0 in the figure) common to the first and second pixels, and the Cb data (Cb1 in the figure) and Cr data (Cr1 in the figure) common to the third and fourth pixels, and obtains YC data for 4 pixels arranged horizontally consisting of 8 signals.

[0107] There is no particular limitation on the method of YC422 conversion at this time. For example, any method such as existing various conversion formulas or the following simple conversion formula may be used. In this embodiment, as an example, YC422 conversion is performed using the following simple conversion formula. Y00 = G00 Y01 = G01 Y10 = G10 Y11 = G11 G0 = (G00 + G01) / 2 G1 = (G10 + G11) / 2 Y0 = (5G0 + 2R0 + B0) / 8 Y1 = (5G1 + 2R1 + B1) / 8 Cb0 = B0 - Y0 Cb1 = B1 - Y1 Cr0 = R0 - Y0 Cr1 = R1 - Y1

[0108] The data sequence rearrangement processing unit 11b separates the YC data generated by the arithmetic processing unit 11a into two Y data groups: a first-pixel Y data group (Y00 and Y10 in the figure) in which the Y data of the first pixel of each unit is arranged continuously, and a second-pixel Y data group (Y01 and Y11 in the figure) in which the Y data of the second pixel of each of the plurality of units is arranged continuously, and outputs them in order as signals for one horizontal row from either one of the Y data groups.

[0109] Also, the data sequence rearrangement processing unit 11b outputs the CbCr data as signals for the other horizontal row without performing rearrangement.

[0110] The RAW conversion unit 23 of the video signal relay device 20 converts the YC data, which is digital data output from the ADC 22, into RAW data by performing a process reverse to that of the YC conversion unit 11 of the video signal transmission device 10. FIG. 12 is a diagram showing the functional configuration of the RAW conversion unit 23 in the video signal relay device 20 of the present embodiment. The hardware configuration of the RAW conversion unit 23 is the same as that of the first embodiment. In the first embodiment, the RAW conversion unit 23 had only the function of the arithmetic processing unit 23b, but the processing of the data sequence reverse rearrangement processing unit 23a, which is a newly added function in the present embodiment, is performed by the processor 81.

[0111] As shown in FIG. 12, the RAW conversion unit 23 includes a data sequence reverse rearrangement processing unit 23a and an arithmetic processing unit 23b. The data sequence reverse rearrangement processing unit 23a performs a reverse rearrangement process on the input YC data, which is the reverse of the rearrangement process by the data sequence rearrangement processing unit 11b of the YC conversion unit 11. Next, the arithmetic processing unit 23b performs a conversion process reverse to the YC conversion process by the arithmetic processing unit 11a of the YC conversion unit 11 on the YC data on which the reverse rearrangement process has been performed, and acquires RAW data.

[0112] Next, the effects of the video signal transmission / reception system of the present embodiment will be described. FIG. 13 is a diagram showing the state of change of the signal state when transmitting a video signal from the video signal transmission device 10 to the video signal relay device 20 of the present embodiment.

[0113] As shown in FIG. 13, in the video signal transmission / reception system of this embodiment, in the YC data, for every two units arranged adjacent to each other in the horizontal direction, a first pixel Y data group in which the Y data of the first pixel of each of the plurality of units is continuously arranged, and a second pixel Y data group in which the Y data of the second pixel of each of the plurality of units is continuously arranged are separated into two Y data groups, and data rearrangement is performed so as to output continuously in order as a horizontal signal from either one of the Y data groups.

[0114] As a result, the number of occurrences of a sharp change in luminance is reduced, and the high-frequency component of the Y data is reduced. Therefore, signal degradation is less likely to occur in the digital-to-analog conversion by the DAC 12 of the video signal transmission device 10 and the analog-to-digital conversion by the ADC 22 of the video signal relay device 20.

[0115] As a result, when the video signal relay device 20 performs RAW conversion on the YC data to obtain RAW data, blurring of the edge and bleeding at the boundary portion can be suppressed, and the image quality can be improved.

[0116] In this embodiment, as an example, the YC conversion unit 11 and the RAW conversion unit 23 perform the above processing for every two units arranged adjacent to each other in the horizontal direction. However, the above data rearrangement processing and reverse rearrangement processing may be performed for every three or more units arranged adjacent to each other in the horizontal direction.

[0117] [Third Embodiment] Next, the video signal transmission / reception system of the third embodiment will be described. The video signal transmission / reception system of this embodiment is different from the video signal transmission / reception system 1 of the second embodiment in that data rearrangement processing and reverse rearrangement processing are performed for every unit arranged adjacent to each other in the horizontal direction of the YC data in the processing of the YC conversion unit 11 of the video signal transmission device 10 and the processing of the RAW conversion unit 23 of the video signal relay device 20.

[0118] In the video signal transmission / reception system of this embodiment, the same components as those in the video signal transmission / reception system 1 of the second embodiment are denoted by the same reference numerals, and description thereof will be omitted unless particularly necessary.

[0119] The rearrangement process of YC data in the video signal transmission / reception system of this embodiment will be described below. FIG. 14 is a diagram for explaining the rearrangement process of YC data in the video signal transmission / reception system of this embodiment.

[0120] In the YC conversion unit 11 of the video signal transmission device 10 of this embodiment, for each unit arranged adjacent to each other in the horizontal direction, a first pixel Y data group in which the first pixel Y data of each of the plurality of units are continuously arranged, and a second pixel Y data group in which the second pixel Y data of each of the plurality of units are continuously arranged are separated into two Y data groups, and one of the Y data groups is sequentially output as a horizontal signal in sequence.

[0121] Specifically, the YC conversion unit 11 includes an arithmetic processing unit 11a and a data sequence rearrangement processing unit 11b. RAW data is input to the YC conversion unit 11 every two rows in the horizontal direction.

[0122] The arithmetic processing unit 11a performs YC422 conversion on the input RAW data to generate YC data. There is no particular limitation on the method of YC422 conversion at this time. For example, any method such as existing various conversion formulas or the following simple conversion formula may be used. In this embodiment, as an example, YC422 conversion is performed using the following simple conversion formula. Note that "n" is the total number of all units arranged adjacent to each other in the horizontal direction. Y00 = G00 Y01 = G01 G0 = (G00 + G01) / 2 Y0 = (5G0 + 2R0 + B0) / 8 Cb0 = B0 - Y0 Cr0 = R0 - Y0 · · · Yn0 = Gn0 Yn1 = Gn1 Gn = (Gn0 + Gn1) / 2 Yn = (5Gn + 2Rn + Bn) / 8 Cbn = Bn - Yn Crn = Rn - Yn

[0123] For the YC data generated by the arithmetic processing unit 11a, the data rearrangement processing unit 11b separates it into two Y data groups: the first-pixel Y data group (Y00 to Yn0 in the figure) in which the Y data of the first pixel of each unit are arranged continuously, and the second-pixel Y data group (Y01 to Yn1 in the figure) in which the Y data of the second pixel of each of a plurality of units are arranged continuously, and outputs it as a signal for one row in the horizontal direction in sequence from either one of the Y data groups.

[0124] Also, for the CbCr data, the data rearrangement processing unit 11b outputs it as a signal for the other row in the horizontal direction without performing rearrangement.

[0125] The RAW conversion unit 23 of the video signal relay device 20 converts the digital data output from the ADC 22 into RAW data by performing the reverse process of the YC conversion unit 11 of the video signal transmission device 10.

[0126] In this way, for each of all the units arranged adjacent to each other in the horizontal direction of the YC data, by performing data rearrangement processing and reverse rearrangement processing, compared with the case where data rearrangement processing and reverse rearrangement processing are performed for each of some of the units arranged adjacent to each other in the horizontal direction of the YC data, the number of occurrences of a sharp change in luminance is further reduced, and the high-frequency components of the Y data are reduced. Therefore, in the digital-to-analog conversion by the DAC 12 of the video signal transmission device 10 and the analog-to-digital conversion by the ADC 22 of the video signal relay device 20, signal degradation is less likely to occur.

[0127] As a result, in the video signal relay device 20, when converting YC data to obtain RAW data, it is possible to further suppress the blurring of edges and the bleeding of boundary portions, thereby further improving the image quality.

[0128] [Modification Example] As described above, the video signal transmission / reception system 1 of the embodiment of the present disclosure has been described. However, the present disclosure is not limited to the above embodiment, and other than the above, within the scope not departing from the gist of the technology of the present disclosure, unnecessary portions may be deleted, new elements may be added, replaced, etc. to the described content and illustrated content shown above, and appropriate changes may be made.

[0129] For example, in the RGB conversion unit 24 of the video signal relay device 20, when converting RAW data to RGB, the demosaicing process may not be performed and the RGB conversion may be performed as it is.

[0130] Also, as shown in FIG. 15, in the video signal relay device 20, the RGB conversion unit 24 may be configured by an integrated circuit IC2 different from the integrated circuit IC1 that constitutes the receiving unit 21, the ADC 22, and the RAW conversion unit 23.

[0131] Also, as shown in FIG. 16, the video signal transmission / reception system 1 may include a camera module device 50 in which the camera 30 and the video signal transmission device 10 are integrated, and a display module device 60 in which the video signal relay device 20 and the display device 40 are integrated.

[0132] Also, as shown in FIG. 17, the display module device 60 may output the signal output from the video signal relay device 20 to the display device 40 and the storage medium 41. Also, the display module device 60 may output the signal output from the video signal relay device 20 only to the storage medium 41.

[0133] As the memory medium 41, for example, any medium such as a ROM (Read Only Memory), a RAM (Random Access Memory), a flash memory, a USB (Universal Serial Bus) memory, an SSD (Solid State Drive), or an HDD (Hard Disk Drive) may be used.

[0134] [Appendix] The preferred embodiments of the present disclosure will be appended below.

[0135] (Appendix 1) A YC conversion unit that receives RAW data output from an image sensor by performing imaging and converts the RAW data into YC data composed of luminance data, first color difference data, and second color difference data and outputs the converted data; A digital-to-analog conversion unit that converts the YC data output from the YC conversion unit into an analog signal and outputs the converted signal; An analog transmission unit that transmits the analog signal converted by the digital-to-analog conversion unit to the outside; A video signal transmission device comprising the above components.

[0136] (Appendix 2) RAW data is video data having one red pixel, one blue pixel, and two green pixels as one unit, The YC conversion unit converts the input RAW data into first luminance data, second luminance data, first color difference data, and second color difference data for each unit, separates the converted data into a luminance data group and a color difference data group, and sequentially outputs the separated luminance data group and color difference data group to the digital-to-analog conversion unit as YC data The video signal transmission device according to Appendix 1.

[0137] (Appendix 3) The YC conversion unit serializes and outputs the separated luminance data group and color difference data group, and includes a data order rearrangement processing unit that rearranges the data order of the first luminance data and the second luminance data between predetermined units and serializes the rearranged data The video signal transmission device according to Supplementary Note 2.

[0138] (Supplementary Note 4) The YC conversion unit converts the RAW data into YC data in YC422 format. The video signal transmission device according to any one of Supplementary Notes 1 to 3.

[0139] (Supplementary Note 5) The YC conversion unit uses a RAW clock corresponding to the signal pitch of the RAW data and a YC clock having a frequency that is 1 / 2 times that of the RAW clock to convert the RAW data into YC data in YC422 format. The YC conversion unit uses a RAW clock corresponding to the signal pitch of the RAW data and a YC clock having a frequency that is 1 / 2 times that of the RAW clock to convert the RAW data into YC data in YC422 format. The video signal transmission device according to any one of Supplementary Notes 1 to 4.

[0140] (Supplementary Note 6) A receiving unit that receives an analog signal transmitted from the video signal transmission device according to Supplementary Note 1, An analog-to-digital conversion unit that converts the analog signal received by the receiving unit into YC data and outputs the YC data, A RAW conversion unit that converts the YC data output from the analog-to-digital conversion unit into RAW data and outputs the RAW data, A video signal relay device including the above components.

[0141] (Supplementary Note 7) When the data order of the luminance data of the YC data is rearranged, the RAW conversion unit includes a data order reverse rearrangement processing unit that rearranges the luminance data in the data order before rearrangement, and converts the YC data rearranged by the data order reverse rearrangement processing unit into RAW data. The video signal relay device according to Supplementary Note 6.

[0142] (Supplementary Note 8) The RAW conversion unit uses a RAW clock corresponding to the signal pitch of the RAW data and a YC clock having a frequency that is 1 / 2 times that of the RAW clock to convert the YC data output from the analog-to-digital conversion unit into RAW data and output the RAW data. The RAW conversion unit uses a RAW clock corresponding to the signal pitch of the RAW data and a YC clock having a frequency that is 1 / 2 times that of the RAW clock to convert the YC data output from the analog-to-digital conversion unit into RAW data and output the RAW data. The video signal relay device according to Supplementary Note 6 or 7.

[0143] (Supplementary Note 9) Further comprising an RGB conversion unit that converts the RAW data output from the RAW conversion unit into RGB data and outputs it. The video signal relay device according to any one of Supplementary Notes 6 to 8.

[0144] (Supplementary Note 10) When converting RAW data into RGB data, the RGB conversion unit performs demosaicing processing. The video signal relay device according to Supplementary Note 9.

[0145] (Supplementary Note 11) When YC data in YC422 format is output from the analog-to-digital conversion unit, the RAW conversion unit converts the YC data in YC422 format into RAW data in RAW8 format, and the RGB conversion unit converts the RAW data in RAW8 format into RGB data in RGB888 format. The video signal relay device according to Supplementary Note 9 or 10.

[0146] (Supplementary Note 12) The RGB conversion unit is constituted by an integrated circuit different from the integrated circuit constituting the receiving unit, the analog-to-digital conversion unit, and the RAW conversion unit. The video signal relay device according to any one of Supplementary Notes 9 to 11.

[0147] (Supplementary Note 13) A camera including the image pickup device, a video signal transmission device according to any one of Supplementary Notes 1 to 5, [[ID=4I7]]a video signal relay device according to any one of Supplementary Notes 6 to 12, and a display device that displays a video based on the signal output from the video signal relay device. A video signal transmission and reception system including the above components.

[0148] (Supplementary Note 14) A camera module device in which the camera and the video signal transmission device are integrated, and a display module device in which the video signal relay device and the display device are integrated. The video signal transmission / reception system according to Supplementary Note 13.

[0149] (Supplementary Note 15) The display module device outputs the signal output from the video signal relay device to a storage medium. The video signal transmission / reception system according to Supplementary Note 14.

Explanation of Signs

[0150] 1 Video signal transmission / reception system 10 Video signal transmission device 11 Image sensor 12 YC conversion unit 13 DAC 14 Transmission unit 20 Video signal relay device 21 Reception unit 22 ADC 23 RAW conversion unit 24 RGB conversion unit 30 Camera 31 Image sensor 40 Display device 41 Storage medium 50 Camera module device 60 Display module device

Claims

1. A YC conversion unit that receives RAW data output from an image sensor by performing imaging, and converts and outputs the RAW data into YC data composed of luminance data, first color difference data, and second color difference data; A digital-to-analog conversion unit that converts the YC data output from the YC conversion unit into an analog signal and outputs it; An analog transmission unit that transmits the analog signal converted by the digital-to-analog conversion unit to the outside; A video signal transmission device comprising:

2. The RAW data is video data with one red pixel, one blue pixel, and two green pixels as one unit, The YC conversion unit converts the input RAW data into first luminance data, second luminance data, first color difference data, and second color difference data for each unit, separates the converted data into a luminance data group and a color difference data group, and sequentially outputs the separated luminance data group and color difference data group to the digital-to-analog conversion unit as YC data The video signal transmission device according to claim 1.

3. The YC conversion unit serializes and outputs the separated luminance data group and color difference data group, and includes a data order rearrangement processing unit that rearranges the data order of the first luminance data and the second luminance data between predetermined units and serializes them The video signal transmission device according to claim 2.

4. The YC conversion unit converts the RAW data into YC data in YC422 format The video signal transmission device according to claim 1.

5. The YC conversion unit uses a RAW clock corresponding to the signal pitch of the RAW data and A YC clock having a frequency that is 1 / 2 of the RAW clock to convert the RAW data into YC data in YC422 format The video signal transmission device according to claim 1.

6. A receiving unit that receives an analog signal transmitted from the video signal transmission device according to claim 1; An analog-to-digital conversion unit that converts the analog signal received by the receiving unit into YC data and outputs it; A RAW conversion unit that converts the YC data output from the analog-to-digital conversion unit into RAW data and outputs it; A video signal relay device comprising:

7. When the data order of the luminance data of the YC data is rearranged, the RAW conversion unit includes a data order reverse rearrangement processing unit that rearranges the luminance data in the data order before rearrangement, and converts the YC data rearranged by the data order reverse rearrangement processing unit into RAW data. The video signal relay device according to claim 6.

8. The RAW conversion unit includes a RAW clock corresponding to the signal pitch of the RAW data, and uses a YC clock having a frequency that is half that of the RAW clock to convert the YC data output from the analog-to-digital conversion unit into RAW data and output it. The video signal relay device according to claim 6.

9. The device further includes an RGB conversion unit that converts the RAW data output from the RAW conversion unit into RGB data and outputs it. The video signal relay device according to claim 6.

10. When converting the RAW data into RGB data, the RGB conversion unit performs demosaicing processing. The video signal relay device according to claim 9.

11. When YC data in YC422 format is output from the analog-to-digital conversion unit, the RAW conversion unit converts the YC data in YC422 format into RAW data in RAW8 format, and the RGB conversion unit converts the RAW data in RAW8 format into RGB data in RGB888 format. The video signal relay device according to claim 9.

12. The RGB conversion unit is constituted by an integrated circuit different from the integrated circuit constituting the receiving unit, the analog-to-digital conversion unit, and the RAW conversion unit. The video signal relay device according to claim 9.

13. A camera including the imaging device, the video signal transmission device according to claim 1, the video signal relay device according to claim 6, and a display device that displays a video based on the signal output from the video signal relay device. A video signal transmission and reception system including the above components.

14. A camera module device in which the camera and the video signal transmission device are integrated, and a display module device in which the video signal relay device and the display device are integrated. The video signal transmission and reception system according to claim 13.

15. The display module device outputs the signal output from the video signal relay device to a storage medium. The video signal transmission and reception system according to claim 14.

Images