JP7205590B2 - Transmitting device, transmitting method, receiving device and receiving method - Google Patents

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 and the like that transmit 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 a video service with a wide luminance range, and reproduce it on the receiver side, so that the perception of the human eye in the natural world is improved. This realizes close display reproduction.

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 levels from 0 to 100%*N (N is greater than 1). It also describes the transmission of a video stream that has

The peak luminance of the monitor on the receiver side (CE monitor) varies greatly depending on the device characteristics of the display panel, backlight arrangement, and design method. too much, or conversely darker than the master monitor. Therefore, it may happen that the luminance atmosphere intended by the production side cannot 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 the reception side to satisfactorily 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 predetermined photoelectric conversion characteristics to input video data;
and a transmission unit for transmitting the transmission video data together with luminance conversion allowable range information for a set area in a screen.

In the present technology, a 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) with a contrast ratio of 0% to 100%*N (where N is a number greater than 1), which exceeds the white peak brightness of conventional LDR (Low Dynamic Range) images. It is the video data of the image.

The transmission unit transmits the transmission video data together with the luminance conversion allowable range information for the set area in the screen. For example, the set area in the screen may be set in units of pixels or in units of blocks containing a predetermined number of pixels. Also, for example, the transmitting unit transmits a video stream obtained by encoding transmission video data, and further includes an information inserting unit that inserts luminance conversion allowable range information into a layer of the video stream. good too.

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

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

Another concept of this technology is
a receiver for receiving 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 processing unit that applies an electro-optical conversion characteristic corresponding to the predetermined photoelectric conversion characteristic to the transmission video data and performs luminance conversion processing based on the luminance conversion allowable range information to obtain output video data. be.

The receiving unit receives the transmission video data together with the luminance conversion allowable range information for the set area in 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) with a contrast ratio of 0% to 100%*N (where N is a number greater than 1), which exceeds the white peak brightness of conventional LDR (Low Dynamic Range) images. It is the video data of the image.

For example, the set area in the screen may be set in units of pixels or in units of blocks containing a predetermined number of pixels. Also, for example, the receiving unit may receive a video stream obtained by encoding transmission video data, and the luminance conversion allowable range information may be inserted into a layer of the video stream. Then, the processing unit applies an electro-optical conversion characteristic corresponding to a predetermined photoelectric conversion characteristic, for example, an inverse characteristic, to the transmission video data, and performs luminance conversion processing based on the luminance conversion allowable range information to output video data. is obtained.

As described above, according to the present technology, transmission video data is received together with luminance conversion allowable range information for a set area in the screen, and luminance conversion processing is performed based on this luminance conversion allowable range information to obtain output video data. 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 transmission video data 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, and the processing unit In areas other than the set area of , 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 receiving side. Note that the effects described in this specification are merely examples and are not limited, and additional effects may be provided.

1 is a block diagram showing a configuration example of a transmission/reception system as an embodiment; FIG. FIG. 2 is a block diagram showing a configuration example of a transmission device that constitutes a transmission/reception system; FIG. 4 is a diagram showing an example of display luminance characteristics of a master monitor; It is a figure which shows an example of a photoelectric conversion characteristic (OETF). FIG. 10 is a diagram showing the access unit at the beginning of a GOP when the coding scheme is HEVC; FIG. 10 is a diagram showing access units other than the head of a GOP when the coding scheme is HEVC; FIG. 4 is a diagram for explaining that a set area in a screen is set in units of pixels or in units of blocks containing a predetermined number of pixels; Fig. 10 is a diagram showing an example structure of a Regional Level Mapping SEI message; FIG. 11 is a diagram showing another structural example of a regional level mapping SEI message; FIG. 4 is a diagram showing the contents of main information in a structural example of a regional level mapping SEI message; 2 is a block diagram showing a configuration example of a receiving device that constitutes a transmission/reception system; FIG. It is a figure which shows an example of an electro-optical transfer characteristic (EOTF). FIG. 4 is a diagram showing an example of display luminance characteristics of a 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. 4 is a diagram showing an example of display luminance characteristics of a 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. 10 is a diagram showing another example of display luminance characteristics of a 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. 11 is a block diagram showing another configuration example of the transmission/reception system;

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, modes 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. Modification

<1. Embodiment>
[Configuration example of transmission/reception system]
FIG. 1 shows a configuration example of a transmission/reception system 10 as an embodiment. This transmission/reception system 10 is composed of a transmission device 100 and a reception device 200 .

The transmitting apparatus 100 generates an MPEG2 transport stream TS as a container, and transmits this transport stream TS on broadcast waves or network packets. This 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) with a contrast ratio of 0% to 100%*N (where N is a number greater than 1), which exceeds the white peak brightness of conventional LDR (Low Dynamic Range) images. It is the video data of the image. Here, the 100% level assumes a luminance level corresponding to a white luminance value of 100 cd/m2.

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

The receiving device 200 receives a transport stream TS transmitted from the transmitting device 100 on a broadcast wave or on a network packet. This transport stream TS has a video stream containing encoded video data. In this video stream, 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.

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

"Transmitter configuration example"
FIG. 2 shows a configuration example of the transmission device 100. As shown in FIG. This transmission device 100 has 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 captures an image of a subject and outputs HDR (High Dynamic Range) video data. This HDR video data has a contrast ratio of 0 to 100%*N (N is a number greater than 1), such as 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 103 a is a monitor for grading HDR video data obtained by the HDR camera 102 . This master monitor 103a has a display luminance level corresponding to HDR video data or suitable for grading HDR video data.

FIG. 3 shows display luminance characteristics 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 the reference level (%), eg, 100% corresponding to a white luminance value of 100 cd/m 2 . Also, 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 the boundary between an area where the luminance displayed on the receiver side monitor (CE monitor) is matched and an area 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 applies the HDR image photoelectric conversion characteristics (HDR OETF curve) to the HDR video data obtained by the HDR camera 102 to obtain transmission video data V1.

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

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 from "64" to "940", or from "4" to "1019" if the extension area is used.

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

[Insert luminance conversion allowable range information]
The details of inserting 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 an access unit at the head of a GOP (Group Of Pictures) when the coding system is HEVC. Also, FIG. 6 shows access units other than the beginning of the GOP when the coding system is HEVC. In the case of the HEVC encoding method, an SEI message group "Prefix_SEIs" for decoding is placed before slices in which pixel data is encoded, and an SEI message group for display "Prefix_SEIs" is placed after the slices. Suffix_SEIs” are placed. As shown in FIGS. 5 and 6, the regional level mapping SEI messages are arranged as an SEI message group "Suffix_SEIs".

The set area in the screen is set in units of pixels or in units of blocks containing a predetermined number of pixels. FIG. 7A shows a setting example for each pixel. In the illustrated example, MR indicates the ridgeline of a mountain, and areas R1 and R3 containing stars and an area R2 containing a neon signboard are set as setting areas. The intention of the production side is that the areas R1 and R3 should be able to display only the twinkling feeling of the stars, and the area R2 is a portion where it is desired to maintain the texture of the neon signboard even though the luminance is high.

Each set area is set as a rectangular area and specified by the upper left pixel coordinates and the 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). Also, 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. 7(b) shows a setting example for each block. The screen is composed of a plurality of blocks divided horizontally and vertically. For example, a block may be 8 pixels*8 pixels, 16 pixels*16 pixels, 32 pixels*32 pixels, or some other size. Each block is indicated by a block ID. In the illustrated example, regions R11, R12, and R13 are set as set regions.

Each set area is set as a rectangular area, and is identified by an upper left block ID and a lower right block ID. That is, the region R11 is identified by the upper left block ID (ID1s) and the lower right block ID (ID1e). Also, the region R12 is identified 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 a regional level mapping SEI message when setting a setting area in units of pixels. FIG. 9 shows a structural example (Syntax) of a regional level mapping SEI message when a setting area is set in units of blocks. FIG. 10 shows the main information content (Semantics) in these structural examples.

"level_mapping_cancel_flag" is 1-bit flag information. "1" indicates to cancel the previous level mapping (Level_mapping) message state. A "0" indicates to transmit each element and refresh the previous state with it.

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

An 8-bit field of "number_of_regions" indicates the number of set regions in the screen. The 16-bit field of "global_compliant_threshold_level" is the mapping display threshold for the entire screen, which is the maximum luminance value that the production side wants to match in the CE display assumed by the production side. show. A 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.

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

A 16-bit field of "position_end_x" and a 16-bit field of "position_end_y" indicate the lower right pixel coordinates that specify the set area. That is, "position_end_x" indicates the horizontal end position of the set 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 set area by the number of pixels with 0 being the upper left of the effective display area.

A 16-bit field of "block_start" indicates the upper left block ID that identifies the set area. That is, "block_start" indicates the ID (block ID) of the starting block when scanning the set area for each corresponding block from the upper left to the lower right of the screen. A 16-bit field of "block_end" indicates the lower right block ID that identifies the set area. That is, "block_end" indicates the ID (block ID) of the end block when scanning the set area for each corresponding block from the upper left to the lower right of the screen. An 8-bit field of "block_size" indicates the size of a block, which is a unit for designating a setting area. For example, if the value is "0x01", the block size is 8x8 pixels, if the value is "0x02", the block size is 16x16 pixels, and if the value is "0x03", the block size is 32x32. A pixel range, etc. are specified.

The 16 bit field of "region_compliant_threshold_level" is the mapping display threshold in the set area, and is the maximum value of luminance that the production side wants to match within the area in the CE display assumed by the production side. Indicates that it is ability dependent. A 16-bit field of "region_compliant_threshold_level_value" indicates the transmission value (transmission code value) of the mapping display threshold within the set region.

An 8-bit field of "peak_percentage" indicates a value expressed as a percentage of the maximum luminance level to 100% on the production side. For example, "peak_percentage" for a peak luminance of 1000 cd/m2 is 1000%. In this case, 100% is 1, and 1000% is 10 times higher, which is expressed 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" in 10-bit transmission expresses 1000%.

In the regional level mapping SEI message described above, the information of "global_compliant_threshold_level" and "global_compliant_threshold_level_value" constitute luminance conversion allowable range information for the entire screen. Information of "region_compliant_threshold_level" and "region_compliant_threshold_level_value" constitute luminance conversion allowable range information for the set area in the screen. As a result, the receiving side can detect luminance conversion allowable range information for the set area and detect luminance conversion allowable range information for other areas from the regional level mapping SEI message.

In this case, luminance conversion allowable range information can be specified for each picture, scene, or program. It should be noted that the type of OETF (optical transfer characteristic) of interest is transmitted in the video usability information (VUI) to the NAL unit of the SPS (sequence parameter set).

Returning to FIG. 2, system encoder 105 generates transport stream TS including video stream VS generated by video encoder 104 . Then, the transmitting unit 106 transmits the transport stream TS to the receiving apparatus 200 on a broadcast wave or network packets.

The operation of the transmission 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 . HDR video data obtained by HDR camera 102 is graded using master monitor 103a. The HDR photoelectric conversion unit 103 applies photoelectric conversion characteristics for HDR images (LDR OETF curve) to the HDR video data to obtain transmission video data V1. This transmission video data V 1 is supplied to the video encoder 104 .

In the video encoder 104, encoding such as MPEG4-AVC, MPEG2 video, or HEVC is applied to the transmission video data V1 to obtain encoded video data.

Also, in this video encoder 104, a video stream (video elementary stream) VS including this encoded video data is generated by a stream formatter (not shown) provided in the latter stage. At this time, the video encoder 104 inserts luminance conversion allowable range information for the set area in the screen and luminance conversion allowable range information for the entire screen into the layer of the video stream.

A video stream VS generated by the video encoder 104 is supplied to the system encoder 105 . This system encoder 105 generates an MPEG2 transport stream TS including a video stream. This transport stream TS is transmitted to the receiving apparatus 200 by the transmission unit 106 on a broadcast wave or network packets.

"Receiving device configuration example"
FIG. 11 shows a configuration example of the receiving device 200. As shown in FIG. This receiving device 200 has a control section 201 , a receiving section 202 , a system decoder 203 , a video decoder 204 , an HDR electro-optical conversion section 206 , a display mapping section 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 a transport stream TS sent from the transmitting apparatus 100 on a broadcast wave or on a network 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 decodes the video stream VS extracted by the system decoder 203 and outputs transmission video data V1. The video decoder 204 also extracts parameter sets and SEI messages 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 (optical-to-electrical conversion characteristics) applied on the transmitting side by specifying the OETF type in the SPS video usability information (VUI), and instructs the HDR electro-optical conversion unit 205 to correspond to the OETF. , for example, an EOTF (electrical-to-optical 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. From this regional level mapping SEI message, the control unit 201 can acquire information of "global_compliant_threshold_level" and "global_compliant_threshold_level_value" that constitute luminance conversion allowable range information for the entire screen. In addition, the control unit 201 can acquire the information of "region_compliant_threshold_level" and "region_compliant_threshold_level_value" that constitute the luminance conversion allowable range information for each set area together with the set area information from this 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 an EOTF (electro-optical conversion characteristic) corresponding to, for example, an inverse characteristic of the OETF (optical conversion characteristic) in the HDR photoelectric conversion unit 103 in the transmission device 100 described above. characteristics) are applied to obtain the output video data for displaying the HDR image.

FIG. 12 shows an example of the electro-optical transfer 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 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 luminance level is PL. Also, when the transmission code value is 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 greater than the threshold level THP is determined by the display mapping unit By the processing in 206, the range up to the display maximum brightness level DP1 of the CE monitor 207 is allocated (high brightness processing). In this figure, the chain double-dashed line b indicates an example of 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 greater than the threshold level THP is is assigned to the range up to the display maximum luminance level DP2 of the CE monitor 207 (lowering luminance processing). In this figure, the dashed-dotted line c indicates an example of luminance conversion processing in that case.

Returning to FIG. 11, the display mapping unit 206 converts the levels exceeding the threshold luminance CL among the output luminance levels of the HDR light-to-light 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 set area in the screen, and uses the luminance CL for the entire screen in 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, the output luminance level is equal to or lower than the threshold luminance CL, the luminance at 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 HDR images based on the output video data of the display mapping section 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 converts the level exceeding the threshold luminance CL to the peak luminance DP In the range up to , a brightness enhancement process that is assigned by a predetermined algorithm is performed.

FIGS. 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 indicates the input luminance level, and the vertical axis indicates the display luminance level. FIG. 13(a) shows a state in which the threshold brightness CL is set to a relatively small value CL(1), and FIG. 13(b) shows a state in which the threshold brightness CL is set to a relatively large value CL(2). is shown.

When the input brightness levels are the threshold brightness levels CL(1) and CL(2), the display brightness levels are the threshold levels THP1 and THP2. That is, until the input luminance level reaches the threshold luminance CL(1), CL(2), the display luminance level is the one intended by the producer. Also, when the input luminance level is the peak luminance PL, the display luminance level is the peak level DP of the CE monitor 207 . That is, when the input luminance level is between the threshold luminances CL(1), CL(2) and the peak luminance PL, the luminance increasing process is performed as indicated by the solid lines L1, L2, for example.

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 converts the level exceeding the threshold luminance CL into a peak In the range up to the luminance DP, luminance reduction processing is performed by allocating with a predetermined algorithm.

14A and 14B show display luminance characteristics of the CE monitor 207 when DP<PL and the maximum luminance 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 indicates the input luminance level, and the vertical axis indicates the display luminance level.

FIG. 14(a) shows a state in which the threshold brightness CL is set to a relatively small value CL(3), and FIG. 14(b) shows a state in which the threshold brightness CL is set to a relatively large value CL(4). is shown. When the input brightness levels are the threshold brightness levels CL(3) and CL(4), the display brightness levels are the threshold levels THP3 and THP4. In other words, the input luminance level up to the threshold luminance CL(3), CL(4) is the display luminance level intended by the producer. Also, when the input luminance level is the peak luminance PL, the display luminance level is the peak level DP of the CE monitor 207 . That is, when the input luminance level is between the threshold luminances CL(3), CL(4) and the peak luminance PL, luminance reduction processing is performed as indicated by solid lines L31, L41, for example.

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 also 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.

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. FIG. When the input luminance level is the threshold luminance CL(3), the display luminance level is the threshold level THP3. That is, until the input luminance level reaches the threshold luminance CL(3), the display luminance level is the one intended by the producer. Also, when the input luminance level is the peak luminance PL, the display luminance level is 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, luminance reduction processing is performed, for example, as indicated by the solid line L32.

FIG. 15B shows a state where 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. FIG. 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 . That is, in this case, the input luminance level up to the threshold luminance CLa is the display luminance level intended by the production side. Further, from the input luminance level CLa to the peak luminance PL, the display luminance level becomes the peak level DP of the CE monitor 207, as indicated by the solid line L42, for example. In this case, for example, it is conceivable to perform display brightness conversion so as to smoothly change the display brightness level on the high brightness side as indicated by the dashed line L41'.

The operation of the receiver 200 shown in FIG. 11 will be briefly described. The receiving unit 202 receives the transport stream TS sent from the transmitting apparatus 100 on a broadcast wave or on a network 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.

A video stream VS extracted by the system decoder 203 is supplied to the video decoder 204 . The video decoder 204 decodes the video stream VS extracted by the system decoder 203 to obtain transmission video data V1. Also, the video decoder 204 extracts parameter sets and SEI messages inserted in each access unit forming the video stream VS, and sends them to the control unit 201 .

The control unit 201 acquires the information of “global_compliant_threshold_level” and “global_compliant_threshold_level_value” that form luminance conversion allowable range information for the entire screen from the regional level mapping SEI message. Also, the control unit 201 acquires the information of "region_compliant_threshold_level" and "region_compliant_threshold_level_value" constituting the luminance conversion allowable range information for each set area together with the set area information from the regional level mapping SEI message.

Transmission video data V<b>1 obtained by the video decoder 204 is supplied to the HDR electro-optic conversion unit 205 . In the HDR electro-optical conversion unit 205, an EOTF (electrical-optical conversion characteristic) corresponding to the OETF (optical-electrical conversion characteristic) in the HDR photoelectric conversion unit 103 in the transmission device 100, for example, having opposite characteristics, is applied to the transmission video data V1 to convert the HDR image. output video data for displaying is obtained. This output video data is supplied to the display mapping unit 206 .

The display mapping unit 206 converts the level exceeding the luminance CL among the output luminance levels of the HDR light-to-light conversion unit 205 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 set area in the screen, and uses the luminance CL for the entire screen in other areas in the screen. The output video data of this display mapping unit 206 is supplied to the CE monitor 207 . An HDR image is displayed on this CE monitor 207 .

As described above, in the transmitting/receiving system 10 shown in FIG. 1, the transmission video data V1 obtained by subjecting the HDR video data to photoelectric conversion is the luminance conversion allowable range for the luminance conversion allowable range information for the set area in the screen. It is sent along with the information. Therefore, on the receiving side, brightness conversion is performed independently for each set area in accordance with the display brightness capability of the CE monitor 207 within the brightness conversion allowable range. becomes.

For example, in the example of FIG. 7A, even if the brightness levels of the stars in regions R1 and R3 and the neon signboard in region R2 are the same, the threshold level CL of regions R1 and R3 is lower than the brightness level. is set, whereas the threshold level CL of region R2 is set higher than its luminance level.

In this case, the brightness of the stars is included in the permissible range of brightness conversion and is subject to display mapping, but the brightness of the neon signboard is not included in the permissible range of brightness conversion and is not subject to display mapping. Therefore, on the receiving side, the intention of the production side that it is sufficient for the regions R1 and R3 to be able to display only the twinkling feeling of the stars, and that the region R2 is a portion that maintains the texture of the neon signboard even though the brightness is high, is conveyed to the receiving side. can be reproduced well.

In the transmitting/receiving system 10 shown in FIG. 1, the transmission video data V1 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. Therefore, on the receiving side, it becomes possible to perform luminance conversion processing on the area other than the set area in the screen based on the luminance conversion allowable range information for the entire screen.

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

In the above-described embodiment, in the receiving apparatus 200, the HDR electro-optic conversion unit 205 performs electro-optic conversion processing, and the display mapping unit 206 performs brightness conversion processing according to the maximum brightness display capability of the CE monitor 207. Indicated. However, by reflecting the luminance conversion characteristic in the electro-optical conversion characteristic (EOTF), the electro-optical conversion process and the luminance conversion process can be simultaneously performed 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 is shown in the above 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, the portion of the television receiver 200 is, for example, a configuration consisting of a set-top box 200A and a monitor 200B connected via a digital interface such as HDMI (High-Definition Multimedia Interface). Note that "HDMI" is a registered trademark.

In this case, when performing display mapping processing, the set top box 200A can determine the maximum brightness level of the monitor 200B based on 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 meta information such as "Vender Specific Info Frame", so that the set-top box 200A and the It is possible to share with the monitor 200B.

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

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

Moreover, this technique can also take the following structures.
(1) a processing unit that obtains transmission video data by applying predetermined photoelectric conversion characteristics to input video data;
A transmitter for transmitting the transmission video data together with luminance conversion allowable range information for a set area in a screen.
(2) The transmitting unit
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 luminance conversion allowable range information for the set area in the screen.
(3) The transmission device according to (1) or (2), wherein the set area in the screen is set in units of pixels or in units of blocks containing a predetermined number of pixels.
(4) the transmission unit transmits a video stream obtained by encoding the transmission video data;
The transmission device according to any one of (1) to (3), further comprising an information inserting unit that inserts the luminance conversion allowable range information into a layer of the video stream.
(5) applying predetermined photoelectric conversion characteristics to input video data to obtain transmission video data;
a transmission step of transmitting the transmission video data together with luminance conversion allowable range information for a set area in a screen by a transmission unit.
(6) a receiver for receiving 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 processing unit that applies an electro-optical conversion characteristic corresponding to the predetermined photoelectric conversion characteristic to the transmission video data and performs luminance conversion processing based on the luminance conversion allowable range information to obtain output video data.
(7) the receiving unit receives the transmission video data together with luminance conversion allowable range information for the entire screen in addition to luminance conversion allowable range information for the set area in the screen;
The receiving device according to (6), wherein the processing unit performs luminance conversion processing based on luminance conversion allowable range information for the entire screen in an area other than the set area in the screen.
(8) The receiver according to (6) or (7), wherein the set area in the screen is set in units of pixels or in units of blocks containing 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 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 processing step of applying an electro-optical conversion characteristic corresponding to the predetermined photoelectric conversion characteristic to the transmission video data, and performing luminance conversion processing based on the luminance conversion allowable range information to obtain output video data.

The main feature of this 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 set area in the screen. 5-9).

DESCRIPTION OF SYMBOLS 10, 10A... Transmission/reception system 100... Transmission apparatus 101... Control part 102... HDR camera 103... HDR photoelectric conversion part 103a... Master monitor 104... Video encoder 105... System encoder 106 Transmitting unit 200 Receiving device 200A Setup box 200B Monitor 201 Control unit 202 Receiving unit 203 System decoder 204 Video decoder 205 ... HDR light-to-light converter 206 ... Display mapping section 207 ... CE monitor

Claims (12)

a processing unit for obtaining transmission video data by applying predetermined photoelectric conversion characteristics to input video data;
a transmission unit for transmitting a video stream containing encoded video data of the transmission video data;
an information inserting unit for inserting type information indicating the photoelectric conversion characteristics into the VUI area of the video stream, and inserting a mapping display threshold for a set area of the screen into the SEI area of the video stream;
The mapping display threshold value is obtained by applying electro-optical conversion processing to the transmission video data based on the type information indicating the opto-electrical conversion characteristics, and combining the first region on the low data level side of the video data and a predetermined luminance conversion algorithm. a threshold for the video data obtained by applying the electro-optical conversion process that indicates a second region on the high data level side of the video data obtained by applying the applicable electro-optical conversion process. The transmitting device according to claim 1, wherein the information inserting unit further inserts coordinate information specifying the set area of the screen into the SEI area of the video stream. The transmission device according to claim 1 or 2, wherein the setting area of the screen is a portion of the entire screen. The transmitting device according to claim 3, wherein the information inserting unit further inserts a mapping display threshold for the entire screen into the SEI area of the video stream. The transmission device according to any one of claims 1 to 4, wherein the mapping display threshold is specified for each picture, for each scene, or for each program. a processing step of applying predetermined photoelectric conversion characteristics to input video data to obtain transmission video data;
a transmission step of transmitting a video stream containing encoded video data of the transmission video data by a transmission unit;
an information inserting step of inserting type information indicating the photoelectric conversion characteristics into the VUI area of the video stream and inserting a mapping display threshold for a set area of the screen into the SEI area of the video stream;
The mapping display threshold value is obtained by applying electro-optical conversion processing to the transmission video data based on the type information indicating the opto-electrical conversion characteristics, and combining the first region on the low data level side of the video data and a predetermined luminance conversion algorithm. A threshold for the video data obtained by applying the electro-optical conversion process that indicates a second region on the high data level side of the video data obtained by applying the applicable electro-optical conversion process. a receiving unit for receiving a video stream containing encoded video data of transmission video data obtained by applying a predetermined photoelectric conversion characteristic to input video data;
Type information indicating the photoelectric conversion characteristics is inserted in the VUI area of the video stream,
A mapping display threshold for the set area of the screen is inserted in the SEI area of the video stream,
The mapping display threshold value is obtained by applying electro-optical conversion processing to the transmission video data based on the type information indicating the opto-electrical conversion characteristics, and combining the first region on the low data level side of the video data and a predetermined luminance conversion algorithm. a threshold for the video data obtained by applying the electro-optical conversion process that indicates a second region on the high data level side of the video data obtained by applying the applicable electro-optical conversion process;
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 data level side is applied to the set area of the screen based on the mapping display threshold. a processing unit that obtains output video data by applying luminance conversion processing according to the predetermined luminance conversion algorithm to the second region of the receiving device. The setting area of the screen is a part of the entire screen,
A mapping display threshold for the entire screen is further inserted in the SEI area of the video stream,
The receiving device according to claim 7, wherein the processing unit uses a mapping display threshold for the entire screen in areas other than the set area of the screen. 9. The receiving device according to claim 7, wherein the processing unit obtains the output video data by simultaneously applying the electro-optical conversion characteristics and the luminance conversion processing to the transmission video data. a receiving step of receiving, by a receiving unit, a video stream containing encoded video data of transmission video data obtained by applying a predetermined photoelectric conversion characteristic to input video data;
Type information indicating the photoelectric conversion characteristics is inserted in the VUI area of the video stream,
A mapping display threshold for the set area of the screen is inserted in the SEI area of the video stream,
The mapping display threshold value is obtained by applying electro-optical conversion processing to the transmission video data based on the type information indicating the opto-electrical conversion characteristics, and combining the first region on the low data level side of the video data and a predetermined luminance conversion algorithm. a threshold for the video data obtained by applying the electro-optical conversion process that indicates a second region on the high data level side of the video data obtained by applying the applicable electro-optical conversion process;
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 data level side is applied to the set area of the screen based on the mapping display threshold. applying luminance conversion processing according to the predetermined luminance conversion algorithm to the second region of to obtain output video data. The setting area of the screen is a part of the entire screen,
A mapping display threshold for the entire screen is further inserted in the SEI area of the video stream,
11. The receiving method according to claim 10, wherein in the processing step, a mapping display threshold for the entire screen is used in areas other than the set area of the screen. 12. The receiving method according to claim 10 or 11, wherein in said processing step, said electro-optical conversion characteristics and said luminance conversion processing are simultaneously applied to said transmission video data to obtain said output video data.

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