JP2020074571A - Transmitting device, transmitting method, receiving device, and receiving method - Google Patents

Abstract

To provide a device and a method that can satisfactorily reproduce a brightness atmosphere intended by a production side on a reception side.SOLUTION: A method applies predetermined photoelectric conversion characteristics to input video data to obtain transmission video data. The method transmits the transmission video data together with brightness conversion allowable range information on preset areas in a screen. A transmission unit transmits a video stream obtained by the transmission video data being encoded and inserts the brightness conversion allowable range information into layers of the video stream. A reception side applies electric photo-conversion characteristics corresponding to the predetermined photoelectric conversion characteristics to the transmission video data, and performs brightness conversion processing independently on each of the preset areas based on the brightness conversion allowable range information to obtain video data for display.SELECTED DRAWING: Figure 5

Description

  The present technology relates to a transmitting device, a transmitting method, a receiving device, and a receiving method, and more particularly, to a transmitting device that transmits transmission video data obtained by applying a predetermined photoelectric conversion characteristic to input video data.

  The HDR (High Dynamic Range) video service reflects the intention of the production side, supplies a video service with a wide luminance range, and reproduces it at the receiver side, thereby perceiving the perception of the human eye in the natural world. It realizes display reproduction close to each other.

  For example, in Non-Patent Document 1, it is generated by encoding transmission video data obtained by applying a gamma curve to input video data having a level of 0 to 100% * N (N is larger than 1). It is described that the video stream is transmitted.

  The peak brightness of the receiver monitor (CE monitor) varies depending on the device characteristics of the display panel, the backlight layout, and the design method. Compared to the master monitor used during program production, the peak brightness of the CE monitor is brighter. It passes or is darker than the master monitor. Therefore, it may happen that the luminance atmosphere intended by the production side cannot be reproduced correctly.

High Efficiency Video Coding (HEVC) text specification draft 10 (for FDIS & Last Call)

  An object of the present technology is to enable the receiving side to favorably reproduce the luminance atmosphere intended by the production side.

The concept of this technology is
A processing unit for obtaining transmission video data by applying a predetermined photoelectric conversion characteristic to the input video data,
And a transmitter that transmits the transmission video data together with luminance conversion permissible range information for a set area on the screen.

  In the present technology, the processing unit applies the predetermined photoelectric conversion characteristic to the input video data to obtain the transmission video data. For example, the input video data is HDR (High Dynamic Range) having a contrast ratio of 0% to 100% * N (N is a number larger than 1) that exceeds the brightness of the white peak of a conventional LDR (Low Dynamic Range) image. This is video data of an image.

  The transmission unit transmits the transmission video data together with the luminance conversion permissible range information for the set area on the screen. For example, the setting area in the screen may be set in a pixel unit or a block unit including a predetermined number of pixels. Further, for example, the transmission unit further includes an information insertion unit that transmits the video stream obtained by encoding the transmission video data and inserts the luminance conversion permissible range information into the layer of the video stream. Good.

  As described above, in the present technology, the transmission video data is transmitted together with the luminance conversion permissible range information for the set area on the screen. Therefore, it is possible for the receiving side to satisfactorily reproduce the brightness atmosphere intended by the production side.

  In addition, in the present technology, for example, the transmission unit may be configured to transmit the transmission video data together with the luminance conversion permissible range information for the entire screen in addition to the luminance conversion permissible range information for the set region in the screen. .. In this case, on the receiving side, in the area other than the set area in the screen, it is possible to perform the brightness conversion process based on the brightness conversion allowable range information for the entire screen.

In addition, another concept of the present technology is
A receiving unit that receives the transmission video data obtained by applying a predetermined photoelectric conversion characteristic to the input video data, together with the luminance conversion permissible range information for the setting area in the screen,
A receiving device comprising: a processing unit that applies an electro-optical conversion characteristic corresponding to the predetermined photoelectric conversion characteristic to the transmission video data, and performs a luminance conversion process based on the luminance conversion permissible range information to obtain output video data. is there.

  The transmission video data is received by the reception unit together with the luminance conversion permissible range information for the set area on the screen. This transmission video data is obtained by applying a predetermined photoelectric conversion characteristic to the input video data. For example, the input video data is HDR (High Dynamic Range) having a contrast ratio of 0% to 100% * N (N is a number larger than 1) that exceeds the brightness of the white peak of a conventional LDR (Low Dynamic Range) image. This is video data of an image.

  For example, the setting area in the screen may be set in pixel units or in block units including a predetermined number of pixels. Further, for example, the receiving unit may receive the video stream obtained by encoding the transmission video data, and the luminance conversion permissible range information may be inserted in the layer of the video stream. Then, the processing unit applies, to the transmitted video data, a photoelectric conversion characteristic corresponding to a predetermined photoelectric conversion characteristic, for example, an inverse characteristic, and performs luminance conversion processing based on the luminance conversion allowable range information to output video data. Is obtained.

  As described above, in the present technology, the transmission video data is received together with the luminance conversion permissible range information for the set area on the screen, and the luminance conversion process is performed based on the luminance conversion permissible range information to obtain the output video data. Is. Therefore, the brightness atmosphere intended by the production side can be reproduced well.

  In the present technology, for example, the receiving unit receives the transmission video data together with the luminance conversion permissible range information for the entire screen in addition to the luminance conversion permissible range information for the set region in the screen, and the processing unit In areas other than the setting area of, the brightness conversion processing may be performed based on the brightness conversion allowable range information for the entire screen.

  According to the present technology, it is possible for the receiving side to satisfactorily reproduce the brightness atmosphere intended by the production side. It should be noted that the effects described in the present specification are merely examples and are not limited, and may have additional effects.

It is a block diagram showing an example of composition of a transmitting and receiving system as an embodiment. It is a block diagram which shows the structural example of the transmitter which comprises a transmission / reception system. It is a figure which shows an example of the display brightness characteristic of a master monitor. It is a figure which shows an example of a photoelectric conversion characteristic (OETF). It is a figure which shows the head access unit of GOP in case an encoding system is HEVC. It is a figure which shows the access unit other than the head of GOP in case an encoding system is HEVC. FIG. 9 is a diagram for explaining that the setting area in the screen is set in pixel units or in block units including a predetermined number of pixels. It is a figure which shows the structural example of a regional level mapping SEI message. It is a figure which shows the other structural example of a regional level mapping SEI message. It is a figure which shows the content of the main information in the structural example of a regional level mapping SEI message. It is a block diagram which shows the structural example of the receiver which comprises a transmission / reception system. It is a figure which shows an example of an electro-optical conversion characteristic (EOTF). It is a figure which shows an example of the display brightness characteristic of CE monitor in case the maximum brightness display capability DP of CE monitor is higher than the maximum brightness PL which the master monitor assumes. It is a figure which shows an example of the display brightness characteristic of CE monitor in case the maximum brightness display capability DP of CE monitor is lower than the maximum brightness PL which the master monitor assumes. It is a figure which shows another example of the display brightness characteristic of a CE monitor in case the maximum brightness display capability DP of a CE monitor is lower than the maximum brightness PL which the master monitor assumes. It is a block diagram which shows the other structural example of a transmission / reception system.

Hereinafter, modes for carrying out the invention (hereinafter, referred to as "embodiments") will be described. The description will be given in the following order.
1. Embodiment 2. Modification

<1. Embodiment>
[Transmission / reception system configuration example]
FIG. 1 shows a configuration example of a transmission / reception system 10 as an embodiment. The transmission / reception system 10 includes a transmission device 100 and a reception device 200.

  The transmitting device 100 generates an MPEG2 transport stream TS as a container, and carries this transport stream TS on a broadcast wave or net packet for transmission. The transport stream TS has a video stream obtained by encoding transmission video data obtained by applying a predetermined photoelectric conversion characteristic to input video data.

  For example, the input video data is HDR (High Dynamic Range) having a contrast ratio of 0% to 100% * N (N is a number larger than 1) that exceeds the brightness of the white peak of a conventional LDR (Low Dynamic Range) image. This is video data of an image. Here, the level of 100% is premised on a brightness level corresponding to a white brightness value of 100 cd / m 2.

  The luminance conversion allowable range information for the set area in the screen and the luminance conversion allowable range information for the entire screen are inserted in the layer of the video stream. Details of the brightness conversion allowable range information will be described later.

  The receiving device 200 receives the transport stream TS sent from the transmitting device 100 in a broadcast wave or a net packet. The transport stream TS has a video stream including encoded video data. As described above, the brightness conversion allowable range information for the set area in the screen and the brightness conversion allowable range information for the entire screen are inserted in the video stream.

  The receiving device 200 applies, to the transmission video data, an electro-optical conversion characteristic of, for example, an inverse characteristic corresponding to the above-described predetermined photoelectric conversion characteristic on the transmission side, and performs a luminance conversion process based on the luminance conversion allowable range information. Get output video data. In this case, luminance conversion is performed only in the luminance conversion allowable range, for example, depending on the peak luminance of the monitor.

"Example of transmitter configuration"
FIG. 2 shows a configuration example of the transmission device 100. The transmission device 100 includes a control unit 101, an HDR camera 102, an HDR photoelectric conversion unit 103, a video encoder 104, a system encoder 105, and a transmission unit 106. The control unit 101 includes a CPU (Central Processing Unit), and controls the operation of each unit of the transmission device 100 based on a control program.

  The HDR camera 102 images a subject and outputs HDR (High Dynamic Range) video data. The HDR video data has a contrast ratio of 0 to 100% * N (N is a number larger than 1), which exceeds the brightness of the white peak of a conventional LDR (Low Dynamic Range) image, for example, 0 to 1000%. Here, the 100% level corresponds to, for example, a white luminance value of 100 cd / m 2. In addition, "cd / m2" represents "cd / square meter".

  The master monitor 103a is a monitor for grading HDR video data obtained by the HDR camera 102. The master monitor 103a has a display brightness level corresponding to the HDR video data or suitable for grading the HDR video data.

  FIG. 3 shows the display luminance characteristic of the master monitor 103a. In this figure, the horizontal axis represents the input brightness level and the vertical axis represents the display brightness level. When the input brightness level is the reference brightness RL, the display brightness level becomes a reference level (%), for example, 100% corresponding to a white brightness value of 100 cd / m 2. When the input brightness level is the peak brightness PL, the display brightness level is the peak level (%).

  The threshold brightness CL is newly defined in this embodiment, and indicates a boundary between a region to be matched as the brightness displayed on the monitor (CE monitor) on the receiver side and a region dependent on the CE monitor. When the monitor input brightness level is the threshold brightness CL, the display brightness level is the threshold level (%).

  Returning to FIG. 2, the HDR photoelectric conversion unit 103 applies photoelectric conversion characteristics (HDR OETF curve) for HDR image to the HDR video data obtained by the HDR camera 102 to obtain the transmission video data V1.

  FIG. 4 shows an example of the photoelectric conversion characteristic (OETF). In this figure, the horizontal axis represents the input brightness level, and the vertical axis represents the transmission code value, like the horizontal axis of the above-mentioned master monitor display brightness characteristics (see FIG. 3). When the input brightness level is the reference brightness RL, the transmission code value becomes the reference level RP. When the input brightness level is the peak brightness PL, the transmission code value becomes the peak level MP. When the input brightness level is the threshold brightness CL, the transmission code value becomes the threshold level THP.

  The range of the transmission code value on the vertical axis corresponds to the input pixel data range of the video encoder 104. For example, in the case of 10-bit encoding, the range is "64" to "940", or the range is "4" to "1019" when the extended area is used.

  Returning to FIG. 2, the video encoder 104 performs encoding such as MPEG4-AVC, MPEG2video, or HEVC (high Efficiency Video Coding) on the transmission video data V1 to obtain encoded video data. The video encoder 104 also generates a video stream (video elementary stream) including the encoded video data by a stream formatter (not shown) provided in the subsequent stage. At this time, the video encoder 104 inserts the luminance conversion permissible range information for the set region in the screen and the luminance conversion permissible range information for the entire screen into the layer of the video stream.

[Insert luminance conversion allowable range information]
The details of insertion of the luminance conversion permissible range information will be described. In this embodiment, a newly defined regional level mapping SEI message (Regional_Level_mapping SEI message) is inserted in the "SEIs" portion of the access unit (AU).

  FIG. 5 shows a head access unit of a GOP (Group Of Pictures) when the encoding method is HEVC. Further, FIG. 6 illustrates access units other than the head of the GOP when the encoding method is HEVC. In the case of the HEVC encoding system, a decoding SEI message group “Prefix_SEIs” is arranged before a slice (slices) in which pixel data is encoded, and a display SEI message group “prefix_SEIs” is arranged after this slice (slices). Suffix_SEIs ”is placed. As shown in FIGS. 5 and 6, the regional level mapping SEI message is arranged as an SEI message group “Suffix_SEIs”.

  The setting area in the screen is set in a pixel unit or a block unit including a predetermined number of pixels. FIG. 7A shows a setting example for each pixel. In the illustrated example, MR indicates a ridgeline of a mountain, and regions R1 and R3 including stars and a region R2 including neon signs are set as setting regions. As the intention of the production side, the areas R1 and R3 need only display the glittering feeling of the stars, and the area R2 is a portion where the texture of the neon signboard is desired to be maintained even though the brightness is high.

  Each setting area is set as a rectangular area, and is specified by the pixel coordinates at the upper left and the pixel coordinates at the lower right. That is, the region R1 is specified by the upper left pixel coordinates (x1s, y1s) and the lower right pixel coordinates (x1e, y1e). The region R2 is specified by the upper left pixel coordinates (x2s, y2s) and the lower right pixel coordinates (x2e, y2e). Further, the region R3 is specified by the upper left pixel coordinates (x3s, y3s) and the lower right pixel coordinates (x3e, y3e).

  FIG. 7B shows a setting example in block units. The screen is composed of a plurality of blocks that are divided into a plurality of blocks in the horizontal and vertical directions. For example, one block has 8 pixels * 8 pixels, 16 pixels * 16 pixels, 32 pixels * 32 pixels, or another size. Each block is indicated by a block ID. In the illustrated example, areas R11, R12, and R13 are set as setting areas.

  Each setting area is set as a rectangular area and is specified by the block ID at the upper left and the block ID at the lower right. That is, the region R11 is specified by the block ID (ID1s) at the upper left and the block ID (ID1e) at the lower right. The region R12 is specified by the block ID (ID2s) on the upper left and the block ID (ID2e) on the lower right. Further, the region R13 is specified by the block ID (ID3s) at the upper left and the block ID (ID3e) at the lower right.

  FIG. 8 shows a structural example (Syntax) of the regional level mapping SEI message in the case where the setting area is set in pixel units. FIG. 9 shows a structural example (Syntax) of the regional level mapping SEI message when setting the setting area in block units. FIG. 10 shows the content (Semantics) of main information in these structural examples.

  “Level_mapping_cancel_flag” is 1-bit flag information. "1" indicates that the message state of the level mapping (Level_mapping) up to that point is canceled. A "0" indicates that each element is transmitted, thus refreshing the previous state.

  The 8-bit field of "coded_data_bit_depth" indicates the bit length of encoded data, and for example, 8 to 14 bits are used. The 16-bit field of “reference_white_level” indicates the input luminance value at 100% in the master monitor 103a, that is, the reference luminance RL. The 16-bit field of “reference_white_level_code_value” indicates a value with a bit precision indicated by “coded_data_bit_depth”, that is, a reference level RP with a level code value of 100% luminance.

  The 8-bit field of "number_of_regions" indicates the number of setting regions on the screen. The 16-bit field of "global_compliant_threshold_level" is the mapping display threshold for the entire screen, which is the maximum value of the brightness that the production side expects to match in the CE display, and the display of levels exceeding this value depends on the display capability. Show. The 16-bit field of "global_compliant_threshold_level_value" indicates the transmission value (transmission code value) of the mapping display threshold for the entire screen.

  The 16-bit field of "position_start_x" and the 16-bit field of "position_start_y" indicate the upper left pixel coordinates that specify the setting area. That is, “position_start_x” indicates the horizontal start position of the setting area by the number of pixels with 0 at the upper left of the effective display area. “Position_start_y” indicates the vertical start position of the set area by the number of pixels with 0 at the upper left of the effective display area.

  The 16-bit field of "position_end_x" and the 16-bit field of "position_end_y" indicate the lower right pixel coordinates that specify the setting area. That is, “position_end_x” indicates the horizontal end position of the setting area by the number of pixels with 0 at the upper left of the effective display area. “Position_end_y” indicates the vertical end position of the set area by the number of pixels with 0 at the upper left of the effective display area.

  The 16-bit field of "block_start" indicates the upper left block ID that identifies the setting area. That is, “block_start” indicates the ID (block ID) of the start block when the setting area is scanned from the upper left to the lower right of the screen for each corresponding block. The 16-bit field of "block_end" indicates the lower right block ID that identifies the setting area. That is, “block_end” indicates the ID (block ID) of the end block when the setting area is scanned from the upper left to the lower right of the screen for each corresponding block. The 8-bit field of “block_size” indicates the size of a block which is a unit for designating the setting area. For example, when the value is “0x01”, the block size is 8 × 8 pixel range, when the value is “0x02”, the block size is 16 × 16 pixel range, and when the value is “0x03”, the block size is 32 × 32. The pixel range is specified.

  The 16-bit field of "region_compliant_threshold_level" is the mapping display threshold in the setting area, which is the maximum value of the brightness that the production side expects to match in the CE display, and the display in the area with a level exceeding this value is displayed. Indicates that it is capacity dependent. The 16-bit field of "region_compliant_threshold_level_value" indicates the transmission value (transmission code value) of the mapping display threshold in the setting area.

  The 8-bit field of “peak_percentage” indicates a value representing the maximum brightness level as a ratio to 100% on the production side. For example, the "peak_percentage" at the peak luminance of 1000 cd / m2 is 1000%. In this case, if 100% is 1, 1000% is 10 times that, and is represented as a value 10. The 16-bit field of "peak_percentage_value" indicates the maximum code value expressing the "peak_percentage" when transmitting with the bit precision indicated by "coded_data_bit_depth", that is, the peak level MP. For example, when "peak_percentage" is 1000%, the maximum value "1019" in 10-bit transmission represents 1000%.

  In the above-mentioned regional level mapping SEI message, the information of “global_compliant_threshold_level” and “global_compliant_threshold_level_value” constitutes luminance conversion allowable range information for the entire screen. Further, the information of "region_compliant_threshold_level" and "region_compliant_threshold_level_value" constitutes luminance conversion allowable range information for the set area on the screen. As a result, the receiving side can detect the luminance conversion permissible range information for the set region and the luminance conversion permissible range information for the other regions from the regional level mapping SEI message.

  In this case, the brightness conversion permissible range information can be designated for each picture, each scene, or each program. The target OETF (photoelectric conversion characteristic) type is transmitted to the NAL unit of SPS (sequence parameter set) in the video usability information (VUI).

  Returning to FIG. 2, the system encoder 105 generates a transport stream TS including the video stream VS generated by the video encoder 104. Then, the transmission unit 106 carries this transport stream TS on a broadcast wave or net packet and transmits it to the reception device 200.

  The operation of the transmitting device 100 shown in FIG. 2 will be briefly described. HDR video data captured by the HDR camera 102 is supplied to the HDR photoelectric conversion unit 103. The HDR video data obtained by the HDR camera 102 is graded using the master monitor 103a. In the HDR photoelectric conversion unit 103, the photoelectric conversion characteristic (LDR OETF curve) for HDR image is applied to the HDR video data to obtain the transmission video data V1. The transmission video data V1 is supplied to the video encoder 104.

  In the video encoder 104, the transmission video data V1 is encoded by, for example, MPEG4-AVC, MPEG2video, or HEVC to obtain encoded video data.

  Further, in the video encoder 104, a stream formatter (not shown) provided in the subsequent stage generates a video stream (video elementary stream) VS including this encoded video data. At this time, in the video encoder 104, the luminance conversion permissible range information for the set area in the screen and the luminance conversion permissible range information for the entire screen are inserted in the layer of the video stream.

  The video stream VS generated by the video encoder 104 is supplied to the system encoder 105. The system encoder 105 generates an MPEG2 transport stream TS including a video stream. The transport stream TS is carried by the transmitting unit 106 on a broadcast wave or net packet and transmitted to the receiving apparatus 200.

"Example of receiver configuration"
FIG. 11 shows a configuration example of the receiving device 200. The receiving device 200 includes a control unit 201, a receiving unit 202, a system decoder 203, a video decoder 204, an HDR lightning conversion unit 206, a display mapping unit 206, and a CE monitor 207. The control unit 201 is configured to include a CPU (Central Processing Unit), and controls the operation of each unit of the receiving device 200 based on a control program.

  The reception unit 202 receives the transport stream TS transmitted from the transmission device 100 in a broadcast wave or a net packet. The system decoder 203 extracts a video stream (elementary stream) VS from this transport stream TS. The system decoder 203 also extracts various information inserted in the layer of the container (transport stream) and sends it to the control unit 201.

  The video decoder 204 performs a decoding process on the video stream VS extracted by the system decoder 203, and outputs transmission video data V1. Further, the video decoder 204 extracts the parameter set and SEI message inserted in each access unit forming the video stream VS and sends them to the control unit 201.

  The control unit 201 recognizes the OETF (photoelectric conversion characteristic) applied on the transmission side by specifying the OETF type in the video usability information (VUI) of the SPS, and causes the HDR electro-optical conversion unit 205 to correspond to the OETF. , EOTF (electro-optical conversion characteristic) having an inverse characteristic is set, for example.

  One of the SEI messages extracted by the video decoder 204 and sent to the control unit 201 includes the above-mentioned regional level mapping SEI message. The control unit 201 can acquire information of “global_compliant_threshold_level” and “global_compliant_threshold_level_value” that configure the luminance conversion allowable range information for the entire screen from this regional level mapping SEI message. In addition, the control unit 201 can acquire information on "region_compliant_threshold_level" and "region_compliant_threshold_level_value" constituting the luminance conversion permissible range information for each setting area together with the setting area information from the regional level mapping SEI message.

  The HDR electro-optical conversion unit 205 corresponds to the transmission video data V1 output from the video decoder 204, and corresponds to the OETF (photoelectric conversion characteristic) of the HDR photoelectric conversion unit 103 in the above-described transmission device 100, for example, EOTF (electro-electric conversion) having an inverse characteristic. Properties) to obtain output video data for displaying the HDR image.

  FIG. 12 shows an example of the electro-optical conversion characteristic (EOTF). In this figure, the horizontal axis represents the transmission code value corresponding to the vertical axis in FIG. The vertical axis represents the output brightness level (display brightness level) corresponding to the horizontal axis in FIG. In this figure, the solid line a is the EOTF curve. When the transmission code value is the peak level MP, the output brightness level is PL. When the transmission code value is the threshold level THP, the output brightness level is CL.

  Here, when the maximum brightness display capability of the CE monitor 207 is higher than the maximum brightness PL assumed by the master monitor 103a, the output brightness level corresponding to the value whose transmission code value is larger than the threshold level THP is the display mapping unit. By the process in 206, the range up to the display maximum brightness level DP1 of the CE monitor 207 is assigned (high brightness process). In this figure, the alternate long and two short dashes line b indicates an example of the luminance conversion process in that case.

  On the other hand, when the maximum brightness display capability of the CE monitor 207 is lower than the maximum brightness PL assumed by the master monitor 103a, the output brightness level corresponding to the value whose transmission code value is larger than the threshold level THP is the display mapping section 206. By the processing in (1), the display is assigned to the range up to the display maximum brightness level DP2 of the CE monitor 207 (low brightness processing). In this figure, the alternate long and short dash line c indicates an example of the luminance conversion process in that case.

  Returning to FIG. 11, the display mapping unit 206 converts a level exceeding the threshold brightness CL among the output brightness levels of the HDR lightning conversion unit 205 according to the maximum brightness display capability of the CE monitor 207 as described above. Here, the display mapping unit 206 uses the luminance CL for the setting area in the screen and the luminance CL for the entire screen in the other areas in the screen.

  In this case, when the transmission code value is equal to or lower than the threshold level THP, that is, when the output luminance level is equal to or lower than the threshold luminance CL, the luminance of the reception level is faithfully reproduced without depending on the CE monitor 207. The side's intention is expressed correctly. The CE monitor 207 displays an HDR image based on the output video data of the display mapping unit 206.

  When the maximum brightness display capability DP of the CE monitor 207 is higher than the maximum brightness PL assumed by the master monitor 103a, that is, DP> PL, the display mapping unit 206 sets the level exceeding the threshold brightness CL to the peak brightness DP. In the range up to, the high brightness processing is performed by a predetermined algorithm.

  13A and 13B show display luminance characteristics of the CE monitor 207 when DP> PL. This characteristic also includes the luminance conversion characteristic of the display mapping unit 206. In this figure, the horizontal axis represents the input brightness level and the vertical axis represents the display brightness level. FIG. 13A shows a state in which the threshold brightness CL is set to a relatively small value CL (1), and FIG. 13B shows a state in which the threshold brightness CL is set to a relatively large value CL (2). Is shown.

  When the input brightness level is the threshold brightness CL (1), CL (2), the display brightness level becomes the threshold levels THP1, THP2. In other words, the display luminance level intended by the production side is obtained until the input luminance level reaches the threshold luminances CL (1) and CL (2). When the input brightness level is the peak brightness PL, the display brightness level is the peak level DP of the CE monitor 207. That is, when the input brightness level is between the threshold brightness CL (1), CL (2) and the peak brightness PL, the brightness enhancement processing is performed as indicated by the solid lines L1, L2, for example.

  If the maximum brightness display capability DP of the CE monitor 207 is lower than the maximum brightness PL assumed by the master monitor 103a, that is, DP <PL, the display mapping unit 206 peaks a level exceeding the threshold brightness CL. Luminance reduction processing is performed in a range up to the luminance DP by a predetermined algorithm.

  14A and 14B show display brightness characteristics of the CE monitor 207 when DP <PL and the maximum brightness display capability DP is relatively high. This characteristic also includes the luminance conversion characteristic of the display mapping unit 206. In this figure, the horizontal axis represents the input brightness level and the vertical axis represents the display brightness level.

  FIG. 14A shows a state in which the threshold brightness CL is set to a relatively small value CL (3), and FIG. 14B shows a state in which the threshold brightness CL is set to a relatively large value CL (4). Is shown. When the input brightness level is the threshold brightness CL (3), CL (4), the display brightness level becomes the threshold levels THP3, THP4. That is, the display luminance level intended by the production side is obtained until the input luminance level reaches the threshold luminances CL (3) and CL (4). When the input brightness level is the peak brightness PL, the display brightness level is the peak level DP of the CE monitor 207. That is, when the input brightness level is between the threshold brightness CL (3), CL (4) and the peak brightness PL, the brightness reduction processing is performed as indicated by solid lines L31, L41, for example.

  FIGS. 15A and 15B show display brightness characteristics of the CE monitor 207 when DP <PL and the maximum brightness display capability DP is relatively low. This characteristic also includes the luminance conversion characteristic of the display mapping unit 206. In this figure, the horizontal axis represents the input brightness level and the vertical axis represents the display brightness level.

  FIG. 15A shows a state in which the threshold brightness CL is set to a relatively small value CL (3) and the threshold level THP3 is lower than the peak level DP of the CE monitor 207. When the input brightness level is the threshold brightness CL (3), the display brightness level is the threshold level THP3. That is, the display brightness level intended by the producer is obtained until the input brightness level reaches the threshold brightness CL (3). When the input brightness level is the peak brightness PL, the display brightness level is the peak level DP of the CE monitor 207. That is, when the input brightness level is between the threshold brightness CL (3) and the peak brightness PL, for example, the brightness reduction processing is performed as indicated by the solid line L32.

  FIG. 15B shows a state in which the threshold brightness CL is set to a relatively large value CL (4) and the threshold level THP4 is higher than the peak level DP of the CE monitor 207. When the input brightness level is the value CLa smaller than the threshold brightness CL (4), the display brightness level becomes the peak level DP of the CE monitor 207. That is, in this case, the display brightness level intended by the producer is obtained until the input brightness level reaches the threshold brightness CLa. Further, when the input brightness level is from CLa to the peak brightness PL, the display brightness level is the peak level DP of the CE monitor 207 as shown by the solid line L42, for example. In this case, for example, display brightness conversion may be performed so as to smoothly change the display brightness level on the high brightness side as indicated by a broken line L41 ′.

  The operation of the receiving apparatus 200 shown in FIG. 11 will be briefly described. The receiving unit 202 receives the transport stream TS sent from the transmitting device 100 in a broadcast wave or a net packet. This transport stream TS is supplied to the system decoder 203. The system decoder 203 extracts a video stream (elementary stream) VS from this transport stream TS.

  The video stream VS extracted by the system decoder 203 is supplied to the video decoder 204. The video decoder 204 performs a decoding process on the video stream VS extracted by the system decoder 203 to obtain transmission video data V1. Further, the video decoder 204 extracts the parameter set and SEI message inserted in each access unit forming the video stream VS, and sends the SEI message to the control unit 201.

  The control unit 201 obtains the information of “global_compliant_threshold_level” and “global_compliant_threshold_level_value” forming the luminance conversion permissible range information for the entire screen from the regional level mapping SEI message. In addition, the control unit 201 obtains, from the regional level mapping SEI message, information on “region_compliant_threshold_level” and “region_compliant_threshold_level_value” that configure the luminance conversion permissible range information for each setting area together with the setting area information.

  The transmission video data V1 obtained by the video decoder 204 is supplied to the HDR electro-optical conversion unit 205. In the HDR electro-optical conversion unit 205, for example, EOTF (electrical-electrical conversion characteristic) having an inverse characteristic corresponding to OETF (photoelectric conversion characteristic) in the HDR photoelectric conversion unit 103 in the transmission device 100 is applied to the transmission video data V1 to obtain the HDR image. Output video data for displaying is obtained. This output video data is supplied to the display mapping unit 206.

  In the display mapping unit 206, of the output brightness levels of the HDR electro-optical conversion unit 205, the level exceeding the brightness CL is converted according to the maximum brightness display capability of the CE monitor 207. At this time, in the display mapping unit 206, the brightness CL for the setting area is used in the setting area in the screen, and the brightness CL for the entire screen is used in the other areas in the screen. The output video data of the display mapping unit 206 is supplied to the CE monitor 207. The HDR image is displayed on the CE monitor 207.

  As described above, in the transmission / reception system 10 shown in FIG. 1, the transmission video data V1 obtained by photoelectrically converting the HDR video data is the brightness conversion permissible range for the brightness conversion permissible range information for the set area in the screen. It is sent with the information. Therefore, on the receiving side, the brightness conversion is independently performed for each set area in accordance with the display brightness capability of the CE monitor 207 within the allowable brightness conversion range, so that the brightness atmosphere intended by the production side can be excellently reproduced. Becomes

  For example, in the case of the example of FIG. 7A, even if the stars in the areas R1 and R3 and the neon signs in the area R2 have the same brightness level, the threshold level CL of the areas R1 and R3 is lower than the brightness level. On the other hand, the threshold level CL of the region R2 is set higher than its brightness level.

  In this case, the luminance of the stars is included in the luminance conversion allowable range and is subject to display mapping, but the luminance of the neon signboard is not included in the luminance conversion allowable range and is not subject to display mapping. Therefore, on the receiving side, the areas R1 and R3 need to display only the glittering feeling of the stars, and the area R2 is a part where the texture of the neon signboard is desired to be maintained even though the brightness is high. It can be reproduced well.

  Further, in the transmission / reception system 10 shown in FIG. 1, the transmission video data V1 is transmitted together with the luminance conversion permissible range information for the entire screen in addition to the luminance conversion permissible range information for the set region in the screen. Therefore, on the receiving side, in the area other than the set area in the screen, the brightness conversion processing can be performed based on the brightness conversion allowable range information for the entire screen.

<2. Modification>
In the above embodiment, an example in which luminance conversion permissible range information for the entire screen is arranged in the regional level mapping SEI message together with luminance conversion permissible range information for a predetermined number of setting areas, and is transmitted to the receiving side showed that. However, a configuration is also conceivable in which only the luminance conversion permissible range information for a predetermined number of setting areas is transmitted to the receiving side. At that time, on the receiving side, in a region other than the set region on the screen, for example, predetermined luminance conversion allowable range information is used.

  Further, in the above-described embodiment, in the receiving device 200, the HDR lightning conversion unit 205 performs the lightning conversion process, and the display mapping unit 206 performs the brightness conversion process according to the maximum brightness display capability of the CE monitor 207. Indicated. However, by reflecting the brightness conversion characteristic in the electro-optical conversion characteristic (EOTF), it is possible to perform the electro-optical conversion process and the brightness conversion process only by the HDR electro-optical conversion unit 205.

  Further, although the transmission / reception system 10 including the transmission device 100 and the receiver 200 has been described in the above-described embodiment, the configuration of the transmission / reception system to which the present technology can be applied is not limited to this. For example, as shown in FIG. 16, a portion of the television receiver 200 has, for example, a configuration including a set top box 200A and a monitor 200B that are connected by a digital interface such as (HDMI (High-Definition Multimedia Interface)). “HDMI” is a registered trademark.

  In this case, when performing the display mapping process, the set top box 200A can determine the maximum brightness level of the monitor 200B based on the information obtained from the EDID of the monitor 200B via HDMI. Alternatively, when the display mapping process is performed by the monitor 200B, the level mapping SEI message, the EOTF type, and the VUI information are defined in the meta information such as “Vender Specific Info Frame”, so that the set top box 200A is It can be shared with the monitor 200B.

  Further, in the above-described embodiment, an example in which the container is a transport stream (MPEG-2 TS) has been shown. However, in the present technology, the transport is not limited to TS, and even in the case of other packets, such as ISOBMFF and MMT, the video layer can be realized by the same method.

  Therefore, the present technology can be similarly applied to a system configured to be distributed to receiving terminals using a network such as the Internet. In Internet delivery, MP4 or other format containers are often used for delivery. That is, as the container, a container of various formats such as a transport stream (MPEG-2 TS) adopted in the digital broadcasting standard and MP4 used in Internet distribution corresponds.

Further, the present technology may also be configured as below.
(1) A processing unit that obtains transmission video data by applying a predetermined photoelectric conversion characteristic to input video data,
A transmission device, comprising: a transmission unit that transmits the transmission video data together with luminance conversion permissible range information for a setting area on the screen.
(2) The transmitting unit is
The transmission device according to (1), wherein the transmission video data is transmitted together with the luminance conversion permissible range information for the entire screen in addition to the luminance conversion permissible range information for the set region in the screen.
(3) The transmission device according to (1) or (2), wherein the setting area in the screen is set in a pixel unit or a block unit including a predetermined number of pixels.
(4) The transmitter transmits a video stream obtained by encoding the transmission video data,
The transmission device according to any one of (1) to (3), further including an information insertion unit that inserts the luminance conversion permissible range information into a layer of the video stream.
(5) a processing step of applying a predetermined photoelectric conversion characteristic to the input video data to obtain transmission video data,
A transmitting step of transmitting, by the transmitting unit, the transmission video data together with the luminance conversion permissible range information for the set area on the screen.
(6) A receiving unit that receives the transmission video data obtained by applying a predetermined photoelectric conversion characteristic to the input video data together with the luminance conversion permissible range information for the set area on the screen,
A receiving device comprising: a processing unit that applies an electro-optical conversion characteristic corresponding to the predetermined photoelectric conversion characteristic to the transmission video data, and performs a brightness conversion process based on the brightness conversion allowable range information to obtain output video data.
(7) The receiving unit receives the transmission video data together with the luminance conversion permissible range information for the entire screen in addition to the luminance conversion permissible range information for the set region in the screen,
The receiving device according to (6), wherein the processing unit performs brightness conversion processing based on brightness conversion permissible range information for the entire screen in an area other than the setting area in the screen.
(8) The receiving device according to (6) or (7), wherein the setting area in the screen is set in a pixel unit or a block unit including a predetermined number of pixels.
(9) The receiving unit receives a video stream obtained by encoding the transmission video data,
The luminance conversion allowable range information is the receiving device according to any one of (6) to (8), which is inserted in a layer of the video stream.
(10) a receiving step of receiving, by the receiving unit, transmission video data obtained by applying a predetermined photoelectric conversion characteristic to the input video data, together with luminance conversion permissible range information for a setting area in the screen;
And a processing step of applying an electro-optical conversion characteristic corresponding to the predetermined photoelectric conversion characteristic to the transmission video data and performing a brightness conversion process based on the brightness conversion permissible range information to obtain output video data.

  The main feature of the present technology is that transmission video data obtained by performing photoelectric conversion on HDR video data is transmitted together with luminance conversion permissible range information for a setting area on the screen, and on the receiving side, each setting area is transmitted. Independently, the luminance conversion is performed only within the luminance conversion allowable range, and it is possible to satisfactorily reproduce the luminance atmosphere intended by the production side (see FIG. 5-9).

10, 10A ... Transmission / reception system 100 ... Transmission device 101 ... Control unit 102 ... HDR camera 103 ... HDR photoelectric conversion unit 103a ... Master monitor 104 ... Video encoder 105 ... System encoder 106 ... Transmission unit 200 ... Reception device 200A ... Setup box 200B ... Monitor 201 ... Control unit 202 ... Reception unit 203 ... System decoder 204 ... Video decoder 205・ ・ ・ HDR electronic conversion unit 206 ・ ・ ・ display mapping unit 207 ・ ・ ・ CE monitor

Claims (12)

A processing unit for obtaining transmission video data by applying a predetermined photoelectric conversion characteristic to the input video data,
The transmission video data, including a type information indicating the photoelectric conversion characteristics, and a transmission unit for transmitting together with a mapping display threshold for a setting area of the screen,
The mapping display threshold indicates the first area on the low brightness level side of the input video data and the second area on the high brightness level side of the input video data to which a predetermined brightness conversion algorithm can be applied. A transmitter that is a threshold for. The transmission device according to claim 1, wherein the transmission unit further transmits coordinate information that specifies a setting area of the screen. The transmission device according to claim 1, wherein the setting area of the screen is a part of the entire screen. The transmission device according to claim 3, wherein the transmission unit further transmits a mapping display threshold for the entire screen. The transmission device according to claim 1, wherein the mapping display threshold is specified for each picture, each scene, or each program. A processing step of obtaining transmission video data by applying a predetermined photoelectric conversion characteristic to the input video data,
A transmission step of transmitting the transmission video data, together with type information indicating the photoelectric conversion characteristics, and a mapping display threshold for a setting area of the screen,
The mapping display threshold indicates the first area on the low brightness level side of the input video data and the second area on the high brightness level side of the input video data to which a predetermined brightness conversion algorithm can be applied. The transmission method that is the threshold for. A transmission video data obtained by applying a predetermined photoelectric conversion characteristic to the input video data, a type information indicating the photoelectric conversion characteristic, and a receiving unit for receiving together with a mapping display threshold for a setting area of the screen,
The mapping display threshold indicates the first area on the low brightness level side of the input video data and the second area on the high brightness level side of the input video data to which a predetermined brightness conversion algorithm can be applied. Is the threshold for
The electro-optical conversion characteristic corresponding to the photoelectric conversion characteristic is applied to the transmission video data based on the type information indicating the photoelectric conversion characteristic, and the high brightness level side based on the mapping display threshold with respect to the setting area of the screen. The receiving apparatus further comprising a processing unit that obtains output video data by applying luminance conversion processing by the predetermined luminance conversion algorithm to the second area of the above. The setting area of the above screen is a part of the whole screen,
The receiving unit further receives a mapping display threshold for the entire screen,
The receiving device according to claim 7, wherein the processing unit uses a mapping display threshold for the entire screen in an area other than the setting area of the screen. The receiving device according to claim 7, wherein the processing unit obtains the output video data by simultaneously applying the electro-optical conversion characteristic and the luminance conversion process to the transmission video data. The receiving unit has a receiving step of receiving the transmission video data obtained by applying a predetermined photoelectric conversion characteristic to the input video data together with the type information indicating the photoelectric conversion characteristic and the mapping display threshold for the set area of the screen. Then
The mapping display threshold indicates the first area on the low brightness level side of the input video data and the second area on the high brightness level side of the input video data to which a predetermined brightness conversion algorithm can be applied. Is the threshold for
The electro-optical conversion characteristic corresponding to the photoelectric conversion characteristic is applied to the transmission video data based on the type information indicating the photoelectric conversion characteristic, and the high brightness level side based on the mapping display threshold with respect to the setting area of the screen. And a processing step of applying luminance conversion processing by the above-mentioned predetermined luminance conversion algorithm to the second region of 1 to obtain output video data. The setting area of the above screen is a part of the whole screen,
In the receiving step, further receives the mapping display threshold for the entire screen,
The receiving method according to claim 10, wherein in the processing step, a mapping display threshold for the entire screen is used in an area other than the setting area of the screen. The receiving method according to claim 10, wherein in the processing step, the output video data is obtained by simultaneously applying the electro-optical conversion characteristic and the brightness conversion processing to the transmission video data.

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