JP6652153B2 - Transmitting device, transmitting method, receiving device and receiving method - Google Patents

Description

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

  HDR (High Dynamic Range) video services reflect the intentions of the production side, provide video services with a wide range of luminance, and reproduce them on the receiver side, thereby improving the perception of the human eye in the natural world. This realizes display reproduction that is brought closer.

  For example, Non-Patent Literature 1 describes that transmission video data 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 greater than 1). It describes that a video stream is transmitted.

  The peak luminance of the monitor on the receiver side (CE monitor) varies widely depending on the device characteristics of the display panel, the arrangement of the backlight, and the design method. The peak luminance of the CE monitor is higher than that of the master monitor used in program production. It is too dark or, on the contrary, darker than the master monitor. For this reason, the luminance atmosphere intended by the production side may not be correctly reproduced.

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

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

The concept of this technology is
A processing unit that obtains transmission video data by applying predetermined photoelectric conversion characteristics to input video data,
A transmission unit that transmits the transmission video data together with luminance conversion allowable range information for a setting area in a screen.

  In the present technology, the processing unit applies predetermined photoelectric conversion characteristics to input video data to obtain 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 greater than 1) exceeding 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 allowable range information for the setting area in the screen. For example, the setting area in the screen may be set in pixel units or block units including a predetermined number of pixels. Further, for example, the transmission unit transmits a video stream obtained by encoding the transmission video data, and further includes an information insertion unit that inserts luminance conversion allowable range information into a layer of the video stream, Is also good.

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

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

Another concept of the present technology is
A transmission unit that receives transmission video data obtained by applying a predetermined photoelectric conversion characteristic to input video data, together with luminance conversion allowable range information for a set area in a screen,
A receiving 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 allowable range information to obtain output video data. is there.

  The receiving unit receives the transmission video data together with the luminance conversion allowable range information for the setting area in the screen. The transmission video data is obtained by applying predetermined photoelectric conversion characteristics 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 greater than 1) exceeding 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 block units including a predetermined number of pixels. Further, for example, the receiving unit may receive a video stream obtained by encoding the transmission video data, and the luminance conversion allowable range information may be inserted in a layer of the video stream. Then, the processing unit applies a light-to-light conversion characteristic corresponding to a predetermined photoelectric conversion characteristic to the transmission video data, for example, a reverse characteristic, and performs a luminance conversion process 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 allowable range information for the set area in the screen, and the output video data is obtained by performing the luminance conversion processing based on the luminance conversion allowable range information. It is. Therefore, it is possible to satisfactorily reproduce the luminance atmosphere intended by the production side.

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

  According to the present technology, it is possible to satisfactorily reproduce the luminance atmosphere intended by the production side on the reception 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.

FIG. 1 is a block diagram illustrating a configuration example of a transmission / reception system as an embodiment. It is a block diagram which shows the example of a structure of the transmission apparatus which comprises a transmission / reception system. FIG. 4 is a diagram illustrating an example of a display luminance characteristic of a master monitor. It is a figure showing an example of photoelectric conversion characteristics (OETF). It is a figure which shows the head access unit of GOP in case an encoding system is HEVC. FIG. 18 is a diagram illustrating access units other than the head of a GOP when the encoding method is HEVC. FIG. 7 is a diagram for explaining that a setting area in a screen is set in pixel units or 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 example of a structure 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 example of a structure of the receiver which comprises a transmission / reception system. It is a figure showing an example of an electro-optic conversion characteristic (EOTF). FIG. 10 is a diagram illustrating an example of the display luminance characteristics of the CE monitor when the maximum luminance display capability DP of the CE monitor is higher than the maximum luminance PL assumed by the master monitor. FIG. 10 is a diagram illustrating an example of display luminance characteristics of the CE monitor when the maximum luminance display capability DP of the CE monitor is lower than the maximum luminance PL assumed by the master monitor. FIG. 14 is a diagram illustrating another example of the display luminance characteristics of the CE monitor when the maximum luminance display capability DP of the CE monitor is lower than the maximum luminance PL assumed by the master monitor. It is a block diagram showing another example of composition of a transmitting and receiving system.

Hereinafter, embodiments for carrying out the invention (hereinafter, referred to as “embodiments”) will be described. The description will be made in the following order.
1. Embodiment 2. Modified example

<1. Embodiment>
[Configuration example of transmission / reception system]
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 transmission device 100 generates an MPEG2 transport stream TS as a container, and transmits the transport stream TS on a broadcast wave or a packet on a net. The transport stream TS has a video stream obtained by encoding transmission video data obtained by applying predetermined photoelectric conversion characteristics 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 greater than 1) exceeding the brightness of the white peak of a conventional LDR (Low Dynamic Range) image. This is video data of an image. Here, the 100% level is based on a luminance level corresponding to a white luminance value of 100 cd / m2.

  In the layer of the video stream, 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. The details of the luminance conversion allowable range information will be described later.

  The receiving device 200 receives the transport stream TS transmitted from the transmitting device 100 in a broadcast wave or a packet of a network. This transport stream TS has a video stream including encoded video data. As described above, 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 into this video stream.

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

"Configuration example of transmission device"
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 greater than 1), for example, 0 to 1000%, which exceeds the brightness of the white peak of a conventional LDR (Low Dynamic Range) image. Here, the 100% level corresponds to, for example, a white luminance value of 100 cd / m2. Note that “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 luminance level corresponding to HDR video data or suitable for grading HDR video data.

  FIG. 3 shows a display luminance characteristic of the master monitor 103a. In this figure, the horizontal axis indicates the input luminance level, and the vertical axis indicates the display luminance level. When the input luminance level is the reference luminance RL, the display luminance level is a reference level (%), for example, 100% corresponding to a white luminance value of 100 cd / m2. When the input luminance level is the peak luminance PL, the display luminance level is the peak level (%).

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

  Returning to FIG. 2, the HDR photoelectric conversion unit 103 obtains transmission video data V1 by applying a photoelectric conversion characteristic (HDR OETF curve) for an HDR image to HDR video data obtained by the HDR camera 102.

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

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

  Returning to FIG. 2, the video encoder 104 performs encoding on the transmission video data V1, such as MPEG4-AVC, MPEG2 video, or HEVC (high efficiency video coding), to obtain encoded video data. Further, the video encoder 104 generates a video stream (video elementary stream) including the encoded video data by using a stream formatter (not shown) provided at a subsequent stage. At this time, the video encoder 104 inserts, into the layer of the video stream, the luminance conversion allowable range information for the set area in the screen and the luminance conversion allowable range information for the entire screen.

[Insert luminance conversion allowable range information]
Details of the insertion of the luminance conversion allowable range information will be described. In this embodiment, a newly defined regional level mapping SEI message (Regional_Level_mapping SEI message) is inserted into 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. FIG. 6 shows access units other than the head of the GOP when the encoding method is HEVC. In the case of the HEVC encoding method, 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 units of pixels or blocks including a predetermined number of pixels. FIG. 7A shows an example of setting in pixel units. In the illustrated example, MR indicates a mountain ridgeline, and regions R1 and R3 including stars and a region R2 including a neon signboard are set as setting regions. As an intention of the creator, the regions R1 and R3 only need to be able to display only the glittering effect of the stars, and the region R2 is a portion where it is desired to maintain the texture of the neon signboard while having high luminance.

  Each setting area is set as a rectangular area, and specified by upper left pixel coordinates and lower right pixel coordinates. 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 upper left pixel coordinates (x2s, y2s) and lower right pixel coordinates (x2e, y2e). Further, the region R3 is specified by upper left pixel coordinates (x3s, y3s) and lower right pixel coordinates (x3e, y3e).

  FIG. 7B shows a setting example in block units. The screen is composed of a plurality of blocks divided into a plurality of sections in the horizontal and vertical directions. For example, one block has a size of 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, regions R11, R12, and R13 are set as setting regions.

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

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

  “Level_mapping_cancel_flag” is 1-bit flag information. “1” indicates that the message state of the previous level mapping (Level_mapping) is cancelled. "0" indicates that each element is transmitted, thereby refreshing the previous state.

  The 8-bit field of "coded_data_bit_depth" indicates the bit length of the encoded data, 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. A 16-bit field of “reference_white_level_code_value” indicates a level code value of 100% luminance with a bit precision indicated by “coded_data_bit_depth”, that is, a reference level RP.

  An 8-bit field of “number_of_regions” indicates the number of setting regions in the screen. The 16-bit field of "global_compliant_threshold_level" is a mapping display threshold value for the entire screen, which is the maximum value of the luminance to be matched in the CE display assumed by the production side, and that the display at a level 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 upper left pixel coordinates for specifying the setting area. That is, “position_start_x” indicates the horizontal start position of the setting area by the number of pixels with the upper left of the effective display area being 0. “Position_start_y” indicates the vertical start position of the setting area by the number of pixels with the upper left of the effective display area being 0.

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

  The 16-bit field of “block_start” indicates the upper left block ID that specifies 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 for specifying 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 specifying a setting area. For example, when the value is “0x01”, the block size is in a range of 8 × 8 pixels, when the value is “0x02”, the block size is in a range of 16 × 16 pixels, and when the value is “0x03”, the block size is 32 × 32. A pixel range is specified.

  The 16-bit field of “region_compliant_threshold_level” is the mapping display threshold value within the setting area, and is the maximum value of the luminance that is desired to be matched within the area in the CE display assumed by the production side. Indicates ability-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 luminance level on the production side as a percentage with respect to 100%. For example, "peak_percentage" at a peak luminance of 1000 cd / m2 is 1000%. In this case, 100% is 1 and 1000% is 10 times that, and is represented as a value of 10. The 16-bit field of “peak_percentage_value” indicates the maximum code value representing “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" at the time of 10-bit transmission represents 1000%.

  In the above-described regional level mapping / SEI message, information of “global_compliant_threshold_level” and “global_compliant_threshold_level_value” constitute luminance conversion allowable range information for the entire screen. Further, the information of “region_compliant_threshold_level” and “region_compliant_threshold_level_value” constitutes the luminance conversion allowable range information for the set area on the screen. Thereby, the receiving side can detect the luminance conversion allowable range information for the set area and the luminance conversion allowable range information for the other areas from the regional level mapping SEI message.

  In this case, the luminance conversion allowable range information can be specified for each picture, each scene, or each program. The type of the target OETF (photoelectric conversion characteristic) is transmitted to the NAL unit of the sequence parameter set (SPS) 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 transmitting unit 106 transmits the transport stream TS to the receiving device 200 by placing the transport stream TS on a broadcast wave or a packet of a network.

  The operation of the transmitting apparatus 100 shown in FIG. 2 will be briefly described. HDR video data obtained by capturing an image with the HDR camera 102 is supplied to the HDR photoelectric conversion unit 103. HDR video data obtained by the HDR camera 102 is graded using the master monitor 103a. The HDR photoelectric conversion unit 103 applies the HDR image photoelectric conversion characteristic (LDR OETF curve) to the HDR video data to obtain transmission video data V1. This transmission video data V1 is supplied to the video encoder 104.

  In the video encoder 104, encoding such as, for example, MPEG4-AVC, MPEG2video, or HEVC is performed on the transmission video data V1, and encoded video data is obtained.

  In the video encoder 104, a video stream (video elementary stream) VS including the encoded video data is generated by a stream formatter (not shown) provided at a subsequent stage. At this time, in the video encoder 104, 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 into the video stream layer.

  The video stream VS generated by the video encoder 104 is supplied to the system encoder 105. In the system encoder 105, an MPEG2 transport stream TS including a video stream is generated. The transport stream TS is transmitted by the transmitting unit 106 to the receiving device 200 in a broadcast wave or a packet of a net.

"Configuration example of receiving device"
FIG. 11 illustrates 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 light-to-light conversion unit 206, a display mapping unit 206, and a CE monitor 207. The control unit 201 includes a CPU (Central Processing Unit), and controls the operation of each unit of the receiving device 200 based on a control program.

  The receiving unit 202 receives the transport stream TS transmitted from the transmitting apparatus 100 in a broadcast wave or a packet on a network. The system decoder 203 extracts a video stream (elementary stream) VS from the transport stream TS. Further, the system decoder 203 extracts various information inserted in the layer of the container (transport stream) and sends the extracted information 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 a parameter set and an SEI message inserted in each access unit constituting the video stream VS, and sends them to the control unit 201.

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

  One of the SEI messages extracted by the video decoder 204 and sent to the control unit 201 includes the above-described regional level mapping SEI message. The control unit 201 can acquire information of “global_compliant_threshold_level” and “global_compliant_threshold_level_value” constituting the luminance conversion allowable range information for the entire screen from the regional level mapping SEI message. Further, the control unit 201 can acquire information of “region_compliant_threshold_level” and “region_compliant_threshold_level_value” constituting the luminance conversion allowable 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 converts the transmission video data V1 output from the video decoder 204 into, for example, an EOTF (electro-optical conversion) having an inverse characteristic corresponding to the OETF (photoelectric conversion characteristic) in the HDR photoelectric conversion unit 103 in the transmission device 100 described above. Characteristic) to obtain output video data for displaying an HDR image.

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

  Here, when the maximum luminance display capability of the CE monitor 207 is higher than the maximum luminance PL assumed by the master monitor 103a, the output luminance level corresponding to the transmission code value larger than the threshold level THP is determined by the display mapping unit. By the processing in 206, the area is allocated to the range up to the display maximum luminance level DP1 of the CE monitor 207 (high luminance processing). In this figure, a two-dot chain line b shows an example of the luminance conversion processing in that case.

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

  Returning to FIG. 11, the display mapping unit 206 converts a level exceeding the threshold luminance CL among the output luminance levels of the HDR electro-optical conversion unit 205 according to the maximum luminance 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 in the setting area, and uses 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 intention of the side 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 luminance display capability DP of the CE monitor 207 is higher than the maximum luminance PL assumed by the master monitor 103a, that is, when DP> PL, the display mapping unit 206 determines that the level exceeding the threshold luminance CL is equal to the peak luminance DP. The brightness enhancement process to be allocated to the range up to the predetermined algorithm is performed.

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

  When the input luminance levels are the threshold luminances CL (1) and CL (2), the display luminance levels are the threshold levels THP1 and THP2. That is, the display luminance level intended by the production side is the input luminance level up to the threshold luminances CL (1) and CL (2). When the input luminance level is the peak luminance PL, the display luminance level becomes the peak level DP of the CE monitor 207. That is, when the input luminance level is between the threshold luminances CL (1) and CL (2) and the peak luminance PL, for example, the high luminance processing is performed as shown by the solid lines L1 and L2.

  When the maximum luminance display capability DP of the CE monitor 207 is lower than the maximum luminance PL assumed by the master monitor 103a, that is, when DP <PL, the display mapping unit 206 sets a level exceeding the threshold luminance CL as a peak. A low-luminance process is performed on a range up to the luminance DP by a predetermined algorithm.

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

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

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

  FIG. 15A shows a state where the threshold luminance 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 luminance level is the threshold luminance CL (3), the display luminance level becomes the threshold level THP3. That is, the display luminance level intended by the production side is up to the input luminance level up to the threshold luminance CL (3). When the input luminance level is the peak luminance PL, the display luminance level becomes the peak level DP of the CE monitor 207. That is, when the input luminance level is between the threshold luminance CL (3) and the peak luminance PL, for example, as shown by the solid line L32, the luminance reduction processing is performed.

  FIG. 15B shows a state in which the threshold luminance 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 luminance level is a value CLa smaller than the threshold luminance CL (4), the display luminance level becomes the peak level DP of the CE monitor 207. In other words, in this case, the display luminance level intended by the production side is up to the input luminance level up to the threshold luminance CLa. When the input luminance level is from CLa to the peak luminance PL, for example, the display luminance level is the peak level DP of the CE monitor 207, as shown by the solid line L42. In this case, for example, it is conceivable to perform display luminance conversion so as to smoothly change the display luminance level on the high luminance 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 transmitted from the transmitting apparatus 100 in a broadcast wave or a packet of a network. This transport stream TS is supplied to the system decoder 203. In the system decoder 203, a video stream (elementary stream) VS is extracted from the transport stream TS.

  The video stream VS extracted by the system decoder 203 is supplied to a video decoder 204. In the video decoder 204, decoding processing is performed on the video stream VS extracted by the system decoder 203, and transmission video data V1 is obtained. In the video decoder 204, a parameter set and an SEI message inserted in each access unit constituting the video stream VS are extracted and sent to the control unit 201.

  The control unit 201 obtains information of “global_compliant_threshold_level” and “global_compliant_threshold_level_value” constituting the luminance conversion allowable range information for the entire screen from the regional level mapping SEI message. Further, the control unit 201 obtains information of “region_compliant_threshold_level” and “region_compliant_threshold_level_value” constituting the luminance conversion permissible range information for each setting region, together with the setting region information, from the regional level mapping / SEI message.

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

  In the display mapping unit 206, a level exceeding the luminance CL among the output luminance levels of the HDR electro-optical conversion unit 205 is converted according to the maximum luminance display capability of the CE monitor 207. At this time, 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 of the screen. The output video data of the display mapping unit 206 is supplied to the CE monitor 207. An 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 subjecting the HDR video data to photoelectric conversion is converted into the luminance conversion allowable range information for the luminance conversion allowable range information for the set area in the screen. It is transmitted with the information. Therefore, on the receiving side, the luminance conversion is performed independently for each setting area in accordance with the display luminance capability of the CE monitor 207 within the luminance conversion allowable range, so that the luminance atmosphere intended by the production side can be reproduced well. Becomes

  For example, in the case of the example of FIG. 7A, even if the brightness levels of the stars in the regions R1 and R3 and the neon signboard in the region R2 are the same, the threshold level CL of the regions 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 the luminance level.

  In this case, the brightness of the star is included in the brightness conversion allowable range and is subject to display mapping, but the brightness of the neon signboard is not included in the brightness conversion allowable range and is not subject to display mapping. Therefore, on the receiving side, it is sufficient that the regions R1 and R3 can display only the sense of glittering stars and the region R2 is a portion where the neon signboard texture is desired to be maintained while the brightness is high. Can be reproduced well.

  In the transmission / reception system 10 shown in FIG. 1, the transmission video data V1 is transmitted together with the luminance conversion allowable range information for the entire screen in addition to the luminance conversion allowable range information for the set area in the screen. Therefore, on the receiving side, in an area other than the setting area in the screen, it is possible to perform the brightness conversion processing based on the brightness conversion allowable range information for the entire screen.

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

  Further, in the above-described embodiment, in the receiving apparatus 200, the HDR electro-optical conversion unit 205 performs the electro-optical conversion process, and the display mapping unit 206 performs the brightness conversion process according to the maximum luminance display capability of the CE monitor 207. Indicated. However, by reflecting the brightness conversion characteristics in the light-to-light conversion characteristics (EOTF), only the HDR light-to-light conversion unit 205 can perform the light-to-light conversion process and the brightness conversion process simultaneously.

  Further, in the above-described embodiment, the transmission / reception system 10 including the transmission device 100 and the receiver 200 has been described, but 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, the television receiver 200 has a configuration including a set-top box 200A and a monitor 200B connected by a digital interface such as an 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 luminance level of the monitor 200B via HDMI based on information obtained from the EDID of the monitor 200B. Alternatively, when the monitor 200B performs the display mapping process, the level mapping / SEI message, the type of the EOTF, and the information of the VUI are defined in meta information such as “Vender Specific Info Frame” so that the set top box 200A It can be shared with the monitor 200B.

  In the above-described embodiment, an example has been described in which the container is a transport stream (MPEG-2 TS). However, in the present technology, the transport is not limited to the TS, and the video layer can be realized by the same method even in the case of another packet, for example, ISOBMFF or MMT.

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

In addition, the present technology may have the following configurations.
(1) a processing unit that applies predetermined photoelectric conversion characteristics to input video data to obtain transmission video data;
A transmission unit that transmits the transmission video data together with luminance conversion allowable range information for a setting area in a screen.
(2) The transmitting unit includes:
The transmission device according to (1), wherein the transmission video data is transmitted together with luminance conversion allowable range information for the entire screen in addition to the luminance conversion allowable range information for the set area in the screen.
(3) The transmission device according to (1) or (2), wherein the setting area in the screen is set in pixel units or block units including a predetermined number of pixels.
(4) The transmitting unit 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 allowable range information into a layer of the video stream.
(5) a processing step of applying predetermined photoelectric conversion characteristics to the input video data to obtain transmission video data;
A transmitting step of transmitting the transmission video data together with luminance conversion allowable range information for a set area in the screen by a transmitting unit.
(6) a receiving unit that receives transmission video data obtained by applying predetermined photoelectric conversion characteristics to input video data together with luminance conversion allowable range information for a set area in a screen;
A receiving 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 allowable range information to obtain output video data.
(7) The receiving unit receives the transmission video data together with the luminance conversion allowable range information for the entire screen in addition to the luminance conversion allowable range information for the set area in the screen,
The receiving device according to (6), wherein the processing unit performs a luminance conversion process based on luminance conversion allowable 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 pixel units or block units including a predetermined number of pixels.
(9) The receiving unit receives a video stream obtained by encoding the transmission video data,
The receiving device according to any one of (6) to (8), wherein the luminance conversion allowable range information is inserted in a layer of the video stream.
(10) a receiving step of receiving, by a receiving unit, transmission video data obtained by applying predetermined photoelectric conversion characteristics to input video data together with luminance conversion allowable range information for a set area in a screen;
Applying a light-to-light conversion characteristic corresponding to the predetermined photoelectric conversion characteristic to the transmission video data and performing a luminance conversion process based on the luminance conversion allowable range information to obtain output video data.

  The main feature of the present technology is that transmission video data obtained by subjecting HDR video data to photoelectric conversion is transmitted together with luminance conversion allowable range information for a setting area in a screen. Independently, the luminance conversion is performed only within the allowable range of the luminance conversion, and the luminance atmosphere intended by the production side can be reproduced well (see FIG. 5-9).

10, 10A transmission / reception system 100 transmission apparatus 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 light-to-light conversion unit 206 ... display mapping unit 207 ... CE monitor

Claims (10)

A processing unit that obtains transmission video data by applying predetermined photoelectric conversion characteristics to input video data,
The transmission video data, type information indicating the photoelectric conversion characteristics, comprising a transmission unit that transmits a mapping display threshold for the setting area of the screen,
The mapping display threshold is determined by applying a first area on the low data level side of the processed video data obtained by applying an electro-optical conversion process to the transmission video data based on the type information indicating the photoelectric conversion characteristic and a predetermined luminance conversion A transmission device, which is a threshold value for the processed video data and indicates a second area on the high data level side of the processed video data to which an algorithm can be applied. The transmission device according to claim 1, wherein the transmission unit further transmits coordinate information that specifies a setting area of the screen. The transmitting 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 value 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;
The transmission unit, the transmission video data, having a type information indicating the photoelectric conversion characteristics, a transmission step of transmitting along with a mapping display threshold for a setting area of the screen,
The mapping display threshold is determined by applying a first area on the low data level side of the processed video data obtained by applying an electro-optical conversion process to the transmission video data based on the type information indicating the photoelectric conversion characteristic and a predetermined luminance conversion A transmission method, which is a threshold value for the processed video data indicating a second area on the high data level side of the processed video data to which an algorithm can be applied. Transmission video data obtained by applying a predetermined photoelectric conversion characteristics to the input video data, type information indicating the photoelectric conversion characteristics, comprising a receiving unit to receive along with a mapping display threshold for the setting area of the screen,
The mapping display threshold value is obtained by performing a light-to-light conversion process on the transmission video data based on the type information indicating the photoelectric conversion characteristic, a first area on a low data level side of the processed video data and a predetermined brightness conversion algorithm. a high data level side threshold for the second region to indicate to the processed video data of the applied may the processed video data,
Based on the type information indicating the upper Symbol photoelectric conversion characteristics to the transmission video data by applying the electro-optic conversion process, the mapping for the screen of the set area of the processed video data obtained by applying the electric light conversion A receiving device further comprising: a processing unit that obtains output video data by applying a luminance conversion process based on the predetermined luminance conversion algorithm to the second area on the high data level side based on a display threshold. The setting area of the screen is a part of the entire 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 processing unit obtains output video data by simultaneously applying the light-to-light conversion process and the brightness conversion process to the transmission video data based on the type information indicating the photoelectric conversion characteristics and the mapping display threshold. The receiving device according to the above. A receiving step of receiving, by the receiving unit, transmission video data obtained by applying predetermined photoelectric conversion characteristics to the input video data, together with type information indicating the photoelectric conversion characteristics and a mapping display threshold for a setting area of a screen; And
The mapping display threshold value is obtained by performing a light-to-light conversion process on the transmission video data based on the type information indicating the photoelectric conversion characteristic, a first area on a low data level side of the processed video data and a predetermined brightness conversion algorithm. a high data level side threshold for the second region to indicate to the processed video data of the applied may the processed video data,
Based on the type information indicating the upper Symbol photoelectric conversion characteristics to the transmission video data by applying the electro-optic conversion process, the mapping for the screen of the set area of the processed video data obtained by applying the electric light conversion Applying a luminance conversion process based on the predetermined luminance conversion algorithm to the second area on the high data level side based on a display threshold to obtain output video data.

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