Reception apparatus and reception method

Abstract

The invention discloses a receiving apparatus and a receiving method. And the visual safety during image switching is ensured. When an image is switched due to non-linear reproduction, during a transient display period, a display attribute is switched to a transient display attribute by which a brightness level remains lower than normal based on pixel statistics of the image. For example, the electro-optical conversion property is controlled to be a transient property, or the brightness level of the backlight is reduced.

Description

[0001] This application is a divisional application. The application number of the parent application is 201880064942.2, the application date is October 10, 2018, and the name of the invention is “Image processing device, image processing method, sending device, sending method and receiving device”. Technical Field

[0002] The present technology relates to an image processing device, an image processing method, a sending device, a sending method and a receiving device, and in particular to an image processing device that ensures visual safety when switching images, etc. Background Art

[0003] For example, NPL 1 describes transmitting an HDR (High Dynamic Range) image in a range from 0 to 100%×N (N is greater than 1).

[0004] [Citation List]

[0005] [Non-patent literature]

[0006] [NPL 1]

[0007] High Efficiency Video Coding (HEVC) ITU-T H.265 standard Summary of the invention

[0008] [Technical issues]

[0009] In HDR images, flash components cause high brightness display during display. It is assumed that linear reproduction that has been checked by the production side is displayed without any problem. However, on the receiving side, when image switching is performed by nonlinear reproduction as in channel switching, random access, system activation, or CM insertion, visual safety may be threatened in the case where the image provided after switching is very bright.

[0010] The purpose of this technology is to ensure visual safety when image switching occurs.

[0011] [Solution to the problem]

[0012] The concept of the present technology lies in an image processing device, comprising:

[0013] The control section, when switching the image, keeps the display attribute switched to a transition display attribute in which the brightness level is kept lower than a normal level during the transition display period based on pixel statistical information about the image.

[0014] In the present technology, when switching images, based on pixel statistical information about the image, the display attribute is switched to a transitional display attribute in which the brightness level is kept lower than the normal level during the transitional display period. For example, the pixel statistical information may include information indicating the ratio of pixels exceeding a threshold level to the entire image. The ratio can determine whether the image is very bright.

[0015] For example, the control unit may utilize pixel statistics information obtained by processing image data. Also, for example, the control unit may utilize information about a transition display period obtained based on the pixel statistics information. Also, for example, the control unit may utilize pixel statistics information extracted from the encoded image data or information about a transition display period. In this case, the processing load may be reduced.

[0016] In addition, for example, as the transition display attribute, there may be a plurality of levels of transition display attributes, and the control section may sequentially apply the plurality of levels of transition display attributes during the transition display period. In this case, the transition display attribute may smoothly transition to the normal display attribute.

[0017] In addition, for example, the control section may maintain the electro-optical conversion property applied to the image data as the transition property during the transition display period. In addition, for example, the control section may maintain the brightness level of the backlight of the display device lower than the normal level during the transition display period.

[0018] Therefore, in the present technology, when switching images, based on pixel statistical information about the image, the display attribute is switched to a transition display attribute in which the brightness level is kept lower than the normal level during the transition display period. Therefore, visual safety can be ensured when image switching occurs.

[0019] In addition, another concept of the present technology is a sending device, including:

[0020] a transmitting unit that transmits a video stream obtained by encoding the image data, and

[0021] The information inserting unit inserts pixel statistics information into the video stream, the pixel statistics information being used to determine whether to switch the display attribute to a transition display attribute in which the brightness level is kept lower than a normal level during a transition display period when switching images.

[0022] In the present technology, the transmitting section transmits a video stream obtained by encoding image data. In this case, the information inserting section inserts pixel statistics information into the video stream, the pixel statistics information being used to determine whether to switch the display attribute to the transition display attribute that maintains a brightness level lower than a normal level during the transition display period when switching images. For example, the pixel statistics information may include information indicating a ratio of pixels exceeding a threshold level to the entire image.

[0023] In addition, for example, the information insertion unit can further insert information about the transition display period into the video stream. In this case, the receiving side can save time and effort in calculating the transition display period. In addition, for example, the information insertion unit can insert the electro-optical conversion transition attribute applied to the image data during the transition display period into the video stream. This enables the receiving side to switch to the electro-optical conversion transition attribute even if the receiving side does not have information about the electro-optical conversion transition attribute.

[0024] In this case, for example, the information about the electro-optical conversion transition attribute may include table information corresponding to the range of variation of the normal electro-optical conversion attribute. This can reduce the amount of information sent. In addition, in this case, for example, as a transition attribute, there may be multiple levels of transition attributes. This enables the receiving side to smoothly transition from the transition attribute to the normal attribute.

[0025] Therefore, in the present technology, pixel statistics information is inserted into a video stream obtained by encoding image data, and the resulting video stream is transmitted, and the pixel statistics information is used to determine whether to keep the display attribute switched to the transition display attribute in which the brightness level is kept lower than the normal level during the transition display period when the image is switched. Therefore, the receiving side can save time and effort in calculating pixel statistics information for determining whether to keep the display attribute switched to the transition display attribute in which the brightness level is kept lower than the normal level during the transition display period when the image is switched.

[0026] In addition, another concept of the present technology is a sending device, including:

[0027] The digital interface part transmits pixel statistics information together with the image data, the pixel statistics information being used to determine whether to switch the display attribute to the transition display attribute in which the brightness level is kept lower than the normal level during the transition display period when the image is switched.

[0028] In the present technology, the digital interface section transmits image data together with pixel statistics information used to determine whether to switch the display attribute to a transition display attribute in which the brightness level remains lower than a normal level during a transition display period when switching images.

[0029] For example, the digital interface unit may further transmit information about the electro-optical conversion transition attribute applied to the image data during the transition display period. This enables the receiving side to switch to the electro-optical conversion transition attribute even if the receiving side does not have information about the electro-optical conversion transition attribute. In this case, the information about the electro-optical conversion transition attribute may include table information corresponding to the range of variation of the normal electro-optical conversion attribute. This can reduce the amount of information transmitted.

[0030] Therefore, in the present technology, the digital interface unit transmits pixel statistics information together with the image data, the pixel statistics information being used to determine whether to switch the display attribute to the transition display attribute in which the brightness level is kept lower than the normal level during the transition display period when the image is switched. Therefore, the receiving side can save time and effort in calculating the pixel statistics information, the pixel statistics information being used to determine whether to switch the display attribute to the transition display attribute in which the brightness level is kept lower than the normal level during the transition display period when the image is switched.

[0031] In addition, another concept of the present invention is a receiving device, comprising:

[0032] A digital interface receives the image data together with pixel statistics information for determining whether to switch the display attribute to a transitional display attribute where the brightness level remains below a normal level during a transitional display period when switching images.

[0033] In the present technology, the digital interface portion receives image data together with pixel statistics information, and the pixel statistics information is used to determine whether to switch the display attribute to the transition display attribute in which the brightness level is maintained below the normal level during the transition display period when the image is switched. This can save time and effort in calculating pixel statistics information, and the pixel statistics information is used to determine whether to switch the display attribute to the transition display attribute in which the brightness level is maintained below the normal level during the transition display period when the image is switched.

[0034] [Beneficial Effects of the Invention]

[0035] According to the present technology, when switching images, visual safety can be ensured. Note that the effects described herein are not necessarily restrictive, and the effects described in the present disclosure may be applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 : is a block diagram showing a configuration example of a transmission and reception system as an embodiment.

[0037] Figure 2 : is a diagram showing a control example of a case where an image on channel A is switched to an image on channel B by channel switching.

[0038] Figure 3 is a diagram showing examples of Type 1, Type 2, and Type 3 HDR properties (HLG) and transition properties (TRTF).

[0039] Figure 4 is a diagram showing examples of Type 1, Type 2, and Type 3 HDR properties (PQ) and transition properties (TRTF).

[0040] Figure 5: is a diagram showing a control example of a case where an image on channel A is switched to an image on channel B by channel switching and a black or gray image is displayed during a specific period immediately after the switching.

[0041] Figure 6 : is a diagram showing a control example of a case where image switching is performed by system activation (power-on) or random access.

[0042] Figure 7 : is a diagram showing a control example of a case where image switching is performed by system activation (power-on) or random access and a black or gray image is displayed during a specific period immediately after the switching.

[0043] Figure 8 : is a diagram showing a control example of a case where image switching is performed by switching between CM and a program.

[0044] Fig. 9 is a block diagram showing a configuration example of a transmitting device.

[0045] Fig.10 is a diagram showing an example of a histogram of the entire image.

[0046] Fig.11 is a diagram showing a position where a transition transfer function SEI message is inserted.

[0047] Fig.12 is a diagram showing a structural example of a statistical information SEI message and the contents of main information in the structural example.

[0048] Fig.13 : is a diagram showing a structural example of a transition transfer function SEI message and the contents of main information in the structural example.

[0049] Fig.14 is a block diagram showing a configuration example of a receiving device.

[0050] Fig.15 is a flowchart showing an example of a process performed by the control section for controlling the photoelectric conversion section in a case where image switching is performed by nonlinear reproduction.

[0051] Fig.16 is a diagram showing a control example taking into account a case where an association with an image before switching is performed.

[0052] Fig.17 is a flowchart showing an example of a process performed by the control section for controlling the photoelectric conversion section in a case where image switching is performed by nonlinear reproduction.

[0053] Fig.18is a block diagram showing a configuration example of a receiving device that realizes transition display attributes through backlight control.

[0054] Fig.19 is a block diagram showing another example of the configuration of the transmitting and receiving system.

[0055] Fig. 20 is a block diagram showing a configuration example of a set-top box.

[0056] Fig.21 : is a diagram showing a structural example of a transition display control HDMI Infoframe and the contents of main information in the structural example.

[0057] Fig. 22 : is a diagram showing a structural example of a transition transfer function HDMI Infoframe and the contents of main information in the structural example.

[0058] Fig.23 is a block diagram showing a configuration example of a monitor.

[0059] Fig.24 is a block diagram showing another example of the configuration of the set-top box.

[0060] Fig.25 is a block diagram showing another example of the configuration of a monitor. DETAILED DESCRIPTION

[0061] Embodiments of the present invention (hereinafter referred to as "embodiments") will be described. Note that the description will be made in the following order.

[0062] 1. Implementation Method

[0063] 2. Modify the example

[0064] <1. Implementation Method>

[0065] [Sending and receiving system]

[0066] Figure 1 An example of a configuration of a transmission and reception system 10 as an embodiment is shown. The transmission and reception system 10 includes a transmission device 100 and a reception device 200.

[0067] The transmitting device 100 transmits a video stream obtained by encoding image data according to H.264 / AVC, H.265 / HEVC, etc. by broadcasting or communication. Pixel statistics information is inserted into the video stream, and the pixel statistics information is used to determine whether to maintain the display attribute switching to the transition display attribute in which the brightness level is maintained lower than the normal level during the transition display period when image switching occurs.

[0068] The pixel statistics information is information indicating, for example, the ratio of pixels exceeding a threshold level to the entire image. By using the pixel statistics information inserted into the video stream, the receiving side can save time and effort in calculating the pixel statistics information to determine whether to switch the display attribute to the transition display attribute in which the brightness level is kept lower than the normal level during the transition display period when image switching occurs.

[0069] In addition to the function of checking the brightness display capability of the display device (display) and switching the display level to a degree capable of displaying the brightness, the present embodiment also includes a function of selecting the electro-optical conversion attribute of the transition period when image switching occurs at the receiver. Therefore, the present embodiment performs switching to the transition display attribute in which the brightness level remains lower than the normal level during the transition display period. In addition, by using the pixel statistics information inserted into the video stream, the reproduction side can save the time and effort of calculating the pixel statistics information to determine whether to switch to the display during the transition period.

[0070] Furthermore, in addition to the above-mentioned pixel statistics, information about the transition display period is inserted into the video stream. This enables the receiving side to save time and effort in calculating the transition display period. In addition, in the video stream, information about the electro-optical conversion transition attribute is further inserted, which is applied to the predetermined motion image data during the transition display period. This enables the receiving side to switch to the electro-optical conversion transition attribute even if the receiving side does not have information about the electro-optical conversion transition attribute. In this case, for example, the information about the electro-optical conversion transition attribute is tabular information corresponding to the range of variation of the normal electro-optical conversion attribute. Therefore, the amount of information sent can be reduced. In addition, a single transition attribute can be used, but the present embodiment uses multiple levels of transition attributes. This enables the receiving side to smoothly transition from the transition attribute to the normal attribute.

[0071] In this embodiment, an SEI message is inserted into the video stream, and the message includes the above-mentioned pixel statistics information, information about the transition display period, and information about the electro-optical conversion transition properties. For example, this embodiment newly defines a statistics SEI message including pixel statistics information and information about conversion properties, and a Transition_Transfer_Function SEI message including information about the electro-optical conversion transition properties.

[0072] The receiving device 200 receives a video stream obtained by encoding predetermined motion image data according to H.264 / AVC, H.265 / HEVC, etc. through broadcasting or communication. The receiving device 200 decodes the received video stream to obtain the predetermined motion image data, and obtains an image based on the predetermined motion image data. For example, the receiving device 200 can not only directly decode the received video stream to reproduce the image, but also reproduce the image by decoding the received video stream passed through the recording and reproduction section.

[0073] When switching images, the receiving device 200 switches the display attribute to a transition display attribute in which the brightness level is kept lower than the normal level during the transition display period based on the pixel statistics information about the image. For example, the pixel statistics information is information indicating the ratio of pixels exceeding the threshold level to the entire image. When the ratio is higher than the threshold, the display attribute is switched to the transition display attribute in which the brightness level is kept lower than the normal level during the transition display period. This makes it possible to ensure visual safety when performing image switching.

[0074] In the case where the pixel statistics information or the information about the transition display period is inserted into the encoded image data (video stream) of the predetermined image data, the receiving device 200 can extract and use the information. This can save time and effort in calculating the pixel statistics information or the transition display period. In addition, the receiving device 200 can process the predetermined motion image data to obtain and use the pixel statistics information or the information about the transition display period.

[0075] In order to change to the transition display attribute in which the brightness level is kept lower than the normal level, the receiving device 200 changes the electro-optical conversion attribute applied to the predetermined motion image data to the transition attribute, keeps the brightness level of the backlight of the display device lower than the normal level, or performs both operations. For example, during the transition display period, a plurality of levels of transition display attributes are utilized and sequentially applied. This enables a smooth transition from the transition display attribute to the normal display attribute.

[0076] In the case where information about the electro-optical conversion transition attribute is inserted into the encoded image data (video stream) of the predetermined image data, the receiving device 200 can extract and use the information. Therefore, even in the case where the receiving device 200 does not have the information about the electro-optical conversion transition attribute, the receiving device 200 can change the electro-optical conversion attribute applied to the predetermined moving image data to the transition attribute to obtain a transition display attribute in which the brightness level is kept lower than the normal level.

[0077] "Aspects of Image Switching"

[0078] Now, various aspects of the case where the reception device 200 performs image switching will be described.

[0079] (1) When switching channels

[0080] Figure 2 An example of a case where an image on channel A is switched to an image on channel B by channel switching is shown. In this example, the image on channel B obtained after the switching is controlled, and during the transition display period (TTh) after the switching, the electro-optical conversion properties are changed to the transition properties (TRTF) to keep the brightness level of the displayed image lower than the normal level. In addition, after the transition display period (TTh) has passed, the electro-optical conversion properties are changed to the normal HDR electro-optical conversion properties (HDR EOTF) to release the brightness level of the image from being kept lower than the normal level.

[0081] In this example, control is provided so that the transition display period is divided into periods T1, T2, and T3, and transition attributes (TRTF) of type 1, type 2, and type 3 are applied to periods T1, T2, and T3, respectively, to increase the brightness level of the displayed image in sequence. Therefore, the conversion attribute is smoothly converted to the normal conversion attribute (HDR EOTF). Note that in the illustrated example, the rectangular frame including the characters "HDR" does not indicate a single picture (frame), but indicates a single picture or a plurality of pictures (frames) together during each of the periods T1, T2, and T3. This also applies to similar numbers described below.

[0082] Figure 3 Examples of HDR properties (HLG) corresponding to normal conversion properties (HDR EOTF) in ITU-R BT.2100 (HLG) and transition properties (TRTF) of Type 1, Type 2, and Type 3 are shown.

[0083] The horizontal axis represents the transmitted code value, and the vertical axis represents the output brightness level. Curve a represents the HDR attribute (HLG), and curve b represents the SDR attribute. For the transmitted code value ranging from 0 to branch level B, the HDR attribute (HLG) has the same trajectory as the SDR attribute. In addition, for the HDR attribute (HLG), the output brightness level P2 corresponds to the maximum level M of the transmitted code value. For the SDR attribute, the output brightness level P1 corresponds to the maximum level M of the transmitted code value.

[0084] For the transitional attributes (TRTF) of type 1, type 2, and type 3, the range of change in which the attributes differ from the HDR attributes (HLG) corresponds to the range of transmission code values from the threshold level H to the maximum level M. Here, the output luminance level P1’ corresponds to the threshold level H. For the transitional attribute of type 1, the output luminance level P1 corresponds to the maximum level M on the transmission code value, as in the case of the SDR attributes. Additionally, for the transitional attribute of type 2, the output luminance level P1a (P1 < P1a < P2) corresponds to the maximum level M of the transmission code value. Additionally, for the transitional attribute of type 3, the output luminance level P1b (P1a < P1b < P2) corresponds to the maximum level M of the transmission code value.

[0085] Figure 4 Examples of the HDR attributes (PQ) corresponding to the normal transitional attributes (HDR EOTF) in ITU-R BT.2100 (PQ) and the transitional attributes (TRTF) of type 1, type 2, and type 3 are shown.

[0086] The horizontal axis represents the transmission code value, and the vertical axis represents the output luminance level. Curve a represents the HDR attributes (PQ), and curve b represents the SDR attributes. For the HDR attributes (PQ), the output luminance level P2 corresponds to the maximum level M of the transmission code value. For the SDR attributes, the output luminance level P1 corresponds to the maximum level M of the transmission code value.

[0087] For the transitional attributes (TRTF) of type 1, type 2, and type 3, the range of change in which the attributes differ from the HDR attributes (PQ) corresponds to the range of transmission code values from the threshold level H to the maximum level M. Here, the output luminance level P1’ corresponds to the threshold level H. For the transitional attribute of type 1, the output luminance level P1 corresponds to the maximum level M on the transmission code value, as in the case of the SDR attributes. Additionally, for the transitional attribute of type 2, the output luminance level P1a (P1 < P1a < P2) corresponds to the maximum level M of the transmission code value. Additionally, for the transitional attribute of type 3, the output luminance level P1b (P1a < P1b < P2) corresponds to the maximum level M of the transmission code value.

[0088] Note that one transitional attribute (e.g., the transitional attribute of type 1) can be applied to the entire transitional display period (TTh).

[0089] (2) When switching channels (via a black / grey image)

[0090] Figure 5An example is shown in which an image on channel A is switched to an image on channel B by channel switching and a black or gray image is displayed during a specific period immediately after the switching. Also in this example, the image on channel B obtained after the switching is controlled, and during the transition display period (TTh) after the black or gray image is displayed, the electro-optical conversion properties are changed to transition properties (TRTF) to keep the brightness level of the displayed image lower than the normal level. In addition, after the transition display period (TTh) has passed, the electro-optical conversion properties are changed to normal HDR electro-optical conversion properties (HDR EOTF) to release the brightness level of the displayed image from being kept lower than the normal level.

[0091] In this example, control is provided so that the transition display period is divided into periods T1, T2, and T3, and transition attributes of type 1, type 2, and type 3 are applied to the periods T1, T2, and T3, respectively (see Figure 3 and Figure 4 ) to sequentially increase the brightness level of the displayed image. Therefore, the transition attribute smoothly transitions to the normal transition attribute (HDR EOTF). Note that one transition attribute (e.g., a transition attribute of type 1) can be applied to the entire transition display period (TTh).

[0092] (3) During system activation and random access

[0093] Figure 6 An example of a case where image switching is performed by system activation (power-on) or random access is shown. In this example, the image provided after system activation or random access is controlled, and during the transition display period (TTh) after switching, the electro-optical conversion property is changed to the transition property (TRTF) to keep the brightness level of the displayed image lower than the normal level. In addition, after the transition display period (TTh) has passed, the electro-optical conversion property is changed to the normal HDR electro-optical conversion property (HDR EOTF) to release the brightness level of the displayed image from being kept lower than the normal level.

[0094] In this example, control is provided so that the transition display period is divided into periods T1, T2, and T3, and transition attributes of type 1, type 2, and type 3 are applied to the periods T1, T2, and T3, respectively (see Figure 3 and Figure 4 ) to sequentially increase the brightness level of the displayed image. Therefore, the transition attribute smoothly transitions to the normal conversion attribute (HDR EOTF). Note that one transition attribute (e.g., a transition attribute of type 1) can be applied to the entire transition display period (TTh).

[0095] (4) During system activation and random access (via black / gray image)

[0096] Figure 7 An example is shown in which image switching is performed by system activation (power-on) or random access and a black or gray image is displayed during a specific period immediately after the switching. Also in this example, control is performed for an image provided after system activation (power-on) or random access, and during a transition display period (TTh) after displaying a black or gray image, the electro-optical conversion properties are changed to transition properties (TRTF) to keep the brightness level of the displayed image lower than the normal level. In addition, after the transition display period (TTh) has passed, the electro-optical conversion properties are changed to normal HDR electro-optical conversion properties (HDREOTF) to release the brightness level of the displayed image from being kept lower than the normal level.

[0097] In this example, control is provided so that the transition display period is divided into periods T1, T2, and T3, and transition attributes of type 1, type 2, and type 3 are applied to the periods T1, T2, and T3, respectively (see Figure 3 and Figure 4 ) to sequentially increase the brightness level of the displayed image. Therefore, the transition attribute smoothly transitions to the normal transition attribute (HDR EOTF). Note that one transition attribute (e.g., a transition attribute of type 1) can be applied to the entire transition display period (TTh).

[0098] (5) When switching between CM and programs

[0099] Figure 8 An example of a case where image switching occurs when switching between CM and a program is shown. In this case, it is assumed that CM is optionally inserted by the receiving side, for example. In this example, control is performed for an image provided after switching from CM to a program or from a program to CM, and during a transition display period (TTh) after the switching, the electro-optical conversion properties are changed to transition properties (TRTF) to keep the brightness level of the displayed image lower than the normal level. In addition, after the transition display period (TTh) has passed, the electro-optical conversion properties are changed to normal HDR electro-optical conversion properties (HDR EOTF) to release the brightness level of the displayed image from being kept lower than the normal level.

[0100] In this example, control is provided so that the transition display period is divided into periods T1, T2, and T3, and transition attributes of type 1, type 2, and type 3 are applied to the periods T1, T2, and T3, respectively (see Figure 3 and Figure 4 ) to sequentially increase the brightness level of the displayed image. Therefore, the transition attribute smoothly transitions to the normal transition attribute (HDR EOTF). Note that one transition attribute (e.g., a transition attribute of type 1) can be applied to the entire transition display period (TTh).

[0101] "Sending device configuration"

[0102] Fig. 9 An example of the configuration of the transmission device 100 is shown. The transmission device 100 includes a control section 101, a photoelectric conversion section 102, an RGB / YCbCr conversion section 103, a statistical information processing section 104, a video encoder 105, a container encoder 106, and a transmission section 107. The control section 101 includes a CPU (Central Processing Unit) that controls the operation of each part of the transmission device 100.

[0103] The photoelectric conversion section 102 performs photoelectric conversion by applying HDR photoelectric conversion properties (HLG curve or PQ curve) to, for example, a high contrast camera output as moving image data (i.e., HDR (High Dynamic Range) image data Vh). The RGB / YCbCr conversion section 103 converts the image data obtained after the photoelectric conversion from the RGB domain to the YCbCr domain. In this case, the RGB / YCbCr conversion section 103 performs conversion based on color space information using a conversion formula corresponding to the color space.

[0104] The statistical information processing section 104 processes the image data obtained by the RGB / YCbCr conversion section 103 to calculate pixel statistical information. In this case, the statistical information processing section 104 calculates the ratio α of pixels whose pixel level exceeds the threshold level (TH_high) to the entire image for each picture (frame).

[0105] Fig.10 An example of a histogram of the entire image is shown. In the histogram, the vertical axis represents frequency and the horizontal axis represents pixel level as a class. The ratio α is calculated by dividing the sum of the frequencies of pixel levels exceeding the threshold level (TH_high) (shaded area) by the sum of the frequencies of all pixel levels.

[0106] The statistical information processing section 104 calculates the ratio α of pixels whose pixel levels exceed the threshold level (TH_high) based on equation (1). In equation (1), the denominator of the right-hand fractional expression represents the number of pixels in the entire image, and the numerator represents the number of pixels whose brightness level exceeds the threshold level (TH_high).

[0107] [Mathematical formula 1]

[0108]

[0109] In addition, the statistical information processing section 104 calculates information about the transition display period TTh transmitted by the transmitting device 100 and information about the ratio α. In this case, first, equation (2) is used to multiply the ratio α by a predetermined coefficient Tc to determine the transition display period TTr. Then, the statistical information processing section 104 converts TTr into an equivalent video frame rate to obtain the transition display period TTh represented by a frame count value.

[0110] [Mathematical formula 2]

[0111]

[0112] The statistical information processing section 104 sends information about the ratio α and the transition display period TTh to the control section 101. The video encoder 105 applies encoding (e.g., MPEG4-AVC or HEVC) to the image data obtained by the RGB / YCbCr conversion section 103 to obtain encoded video data, and obtains a video stream (video elementary stream) including the encoded video data.

[0113] At this time, the video encoder 105 inserts meta information indicating that the video stream is an HDR stream and further indicating electro-optical conversion properties, etc., into the VUI (Video Usability Information) area of ​​the SPS NAL unit of the access unit (AU). In addition, the video encoder 105 inserts the above-mentioned statistics SEI message and transition transfer function SEI message into the "SEI" part of the access unit (AU).

[0114] Note that a statistics SEI message including pixel statistics or information about a transition display period is inserted into the access unit of each picture, but a transition transfer function SEI message including information about electro-optical conversion transition properties does not need to be inserted into the access unit of each picture, and is inserted into, for example, the beginning of a scene and an access unit of a picture corresponding to a GOP (Group of Pictures).

[0115] In addition, information about the electro-optical transition attributes can be inserted into the layer in the container described below. For example, for MPEG-2TS or MMT, information about the electro-optical transition attributes is inserted into the descriptor. For MP4 (ISO BMFF), information about the electro-optical transition attributes is inserted into the box in the moof. For DASH-based broadcasting, information about the electro-optical transition attributes is inserted into the MPD through the "Supplementary Attribute Descriptor".

[0116] The statistics SEI message includes pixel statistics as described above or information about a transition display period. Fig.12 (a) shows an example of the structure (Syntax) of the statistics information SEI message. Fig.12(b) shows the contents (semantics) of the main information in the structure example.

[0117] The 4-bit field "EOTF type" indicates the type of EOTF. For example, "1" indicates "ITU-R Rec. BT.709 (gamma)", "2" indicates "ITU-R Rec. BT.2100 PQ", and "3" indicates "ITU-R Rec. BT.2100 HLG".

[0118] The 16-bit field "threshold_level" indicates the lower threshold of the pixel level value of the target for statistical information, in other words, the threshold level (TH_high). The 8-bit field "high_level_target_ratio" indicates the value of the ratio α of the pixel of the target for the transition attribute to the entire image. This ratio is multiplied by 100 to obtain a percentage value. The 16-bit field "transition_period" indicates the transition display period TTh expressed as a frame count value.

[0119] Additionally, the transition transfer function SEI message includes information on the electro-optical conversion transition properties as described above. Fig.13 (a) shows an example of the structure (Syntax) of the transition transfer function SEI message. Fig.13 (b) shows the contents (semantics) of the main information in the structure example.

[0120] The 8-bit field "number_of_transition_types" indicates the number of types of transition attributes. Information on the transition attributes is presented repeatedly such that the number of repetitions is equal to the number of types of transition attributes.

[0121] The 4-bit field "transitionTF Type" indicates the type of transition attribute. For example, "1" indicates type 1, "2" indicates type 2, and "3" indicates type 3 (see Figure 3 and Figure 4 ). The 16-bit field "minimum_level" indicates the minimum input pixel level of the curve for which the target EOTF is changed (see Figure 3 and Figure 4 The 16-bit field "maximum_level" indicates the maximum input pixel level of the curve for which the target EOTF is changed (see Figure 3 and Figure 4 The maximum level M of the code values ​​sent in the transmission.

[0122] The 16-bit field "trace_pivot_size" indicates the number of points through which the transition attribute is traced. The 16-bit field "input_level(j)" and the 16-bit field "output_level(j)" are presented repeatedly, so that the number of repetitions is equal to the number of points through which the transition attribute is traced. The field "input_level(j)" indicates the input pixel level of the transition attribute. The field "output_level(j)" indicates the output value of the transition attribute corresponding to the input level.

[0123] Return to reference Fig. 9 , the container encoder 106 generates a container including the video stream generated by the video encoder 105 as a broadcast stream, for example, MPEG-2TS, MMT, MP4 (ISOMMFF). At this time, information about the electro-optical conversion transition attribute similar to the information included in the above-mentioned transition transfer function SEI message can be inserted into the layer in the container. The transmission unit 107 transmits the broadcast stream obtained by the container encoder 106 to the receiving device 200 through broadcasting or communication.

[0124] Will briefly describe Fig. 9 The operation of the transmission device 100 shown in FIG. 1 is as follows. For example, HDR image data Vh used as a high contrast camera output is supplied to the photoelectric conversion section 102. The photoelectric conversion section 103 applies photoelectric conversion to the HDR image data Vh using the HDR photoelectric conversion property, and obtains image data as a video material generated by the HDR OETF.

[0125] The HDR image data obtained by the photoelectric conversion section 102 is supplied to the RGB / YCbCr conversion section 103. The RGB / YCbCr conversion section 103 converts the image data obtained by the photoelectric conversion section 102 from the RGB domain to the YCbCr domain. The image data converted into the YCbCr domain is supplied to the statistical information processing section 104 and the video encoder 105.

[0126] The statistical information processing unit 104 processes the image data obtained by the RGB / YCbCr conversion unit 103 to calculate pixel statistical information. In this embodiment, for each picture (frame), the ratio α of each pixel whose pixel level exceeds the threshold level (TH_high) to the entire image is calculated (see equation (1)).

[0127] In addition, the statistical information processing section 104 calculates information about the transition display period TTh transmitted by the transmitting device 100 and information about the ratio α. In this case, the ratio α is multiplied by a predetermined coefficient Tc to determine a transition display period TTr in time units (see equation (2)), which is then converted into an equivalent video frame rate to obtain a transition display period TTh expressed as a frame count value. The information about the ratio α and the information about the transition display period TTh calculated by the statistical information processing section 104 are transmitted to the control section 101.

[0128] The video encoder 105 applies encoding, for example, MPEG4-AVC or HEVC, to the image data obtained by the RGB / YCbCr conversion section 103 to obtain encoded video data, and generates a video stream (video elementary stream) including the encoded video data.

[0129] At this time, the video encoder 105 inserts meta information indicating that the video stream is an HDR stream and further indicating HDR electro-optical conversion properties, etc., into the VUI (Video Usability Information) area of ​​the SPS NAL unit of the access unit (AU). In addition, the video encoder 105 inserts a statistics information SEI message including information about the ratio α and information about the above-mentioned transition display period TTh into the "SEI" part of the access unit (AU) (see Fig.12 (a)), and further inserting a transition transfer function SEI message including information about the electro-optical conversion transition properties into the "SEI" part of the access unit (AU) (see Fig.13 (a)).

[0130] The video stream obtained by the video encoder 105 is supplied to the container encoder 106. The container encoder 106 generates a container including the video stream as a broadcast stream, for example, MPEG-2TS, MMT, MP4 (ISOBMFF). The transmission section 107 transmits the broadcast stream to the reception device 200 by broadcasting or communication.

[0131] "Configuration example of receiving device"

[0132] Fig.14 An example of the configuration of the receiving apparatus 200 is shown. The receiving apparatus 200 includes a control section 201, a receiving section 202, a container decoder 203, a video decoder 204, a statistical information processing section 205, a YCbCr / RGB conversion section 206, an electro-optical conversion section 207, and a display device 208.

[0133] The control section 201 includes a CPU (central processing unit) that controls the operation of each part of the receiving device 200 based on a control program. The receiving device 200 receives a broadcast stream from the transmitting device 100 by broadcasting or communication. The receiving device 200 includes a recording and reproducing section 202a, and outputs the received broadcast stream (MPEG-2TS, MMT, MP4 (ISO MMFF) etc.) directly or via the recording and reproducing section 202a. In the case of outputting the broadcast stream via the recording and reproducing section 202a, random access is allowed. In addition, the receiving section 202 includes a channel switching function.

[0134] The container decoder 203 extracts a video stream from the broadcast stream (MPEG-2 TS, MMT, MP4 (ISO MMFF), etc.) output by the receiving unit 202 .

[0135] The video decoder 204 performs a decoding process on the video stream extracted by the container decoder 203 to obtain HDR image data. In addition, the video decoder 204 extracts a parameter set or SEI message for each access unit included in the inserted video stream, and transmits the parameter set or SEI message to the control section 201. In the transmitting device 100, as described above, the statistical information SEI message (see Fig.12 (a)) or transition transfer function SEI message (see Fig.13 When (a)) is inserted into the video stream, the SEI message is also sent to the control unit 201.

[0136] Based on the meta information in the VUI area of ​​the SPS NAL unit, the control unit 201 recognizes that the video stream is an HDR stream, and also recognizes HDR electro-optical conversion attribute information, etc. In addition, the control unit 201 checks the brightness display capability of the display device (display) on the display device side, and selects the electro-optical conversion attribute of the transition period to the extent that the brightness can be displayed. At this time, the control unit 201 obtains pixel statistical information (information about the ratio α of pixels whose level exceeds the threshold level (TH_high) to the entire image for each pixel) and information about the transition display period TTh from the above-mentioned statistical information SEI message. In addition, the control unit 201 obtains information about the electro-optical conversion transition attribute from the above-mentioned transition transfer function SEI message.

[0137] When the pixel statistical information (information about the ratio α of pixels each of which pixel level exceeds the threshold level (TH_high) with respect to the entire image) and the information about the transition display period TTh cannot be acquired from the above-mentioned statistical information SEI message, the statistical information processing section 205 processes the image data obtained by the video decoder 204 in a manner similar to Fig. 9The statistical information processing section 205 calculates the information about the ratio α and the information about the transition display period TTh to the control section 201.

[0138] The YCbCr / RGB conversion section 206 converts the image data obtained by the video decoder 204 from the YCbCr (luminance and color difference) domain to the RGB domain. The electro-optical conversion section 207 applies electro-optical conversion properties to the image data converted into the RGB domain by the YCbCr / RGB conversion section 206 to obtain display image data. The display device 208 is, for example, a liquid crystal display (LCD), and displays an image based on the display image data.

[0139] Under the control of the control section 201, the electro-optical conversion section 207 normally applies a normal HDR electro-optical conversion property (HDREOTF), but in the case where image switching is performed by nonlinear reproduction (such as in channel switching, system activation, random access, and CM / program switching), a transition property (TRTF) is applied during a transition display period (TTh) after switching to keep the brightness level of the displayed image lower than the normal level (see Figure 2 and Figures 5 to 8 ).

[0140] In this case, as the transition attribute, one or more transition attributes are used. As information about the transition attribute, relevant information provided in advance in the receiving device 200 is used, and when such information is not provided, information about the electro-optical conversion transition attribute obtained from the transition transfer function SEI message as described above is used.

[0141] In the case where there are multiple transition attributes, the electro-optical conversion section 207, under the control of the control section 201, divides the transition display period into multiple periods (the periods are not necessarily equal) and applies multiple levels of transition attributes in sequence. This allows the transition attribute to smoothly transition to the HDR electro-optical conversion attribute (HDR EOTF). Figure 2 and Figures 5 to 8 The example in shows the case of preparing three transition properties.

[0142] Fig.15 The flowchart in FIG. 2 shows an example of a process for controlling the electro-optical converter 207 executed by the control section 201 in the case where image switching is performed by nonlinear reproduction. The nonlinear control section 201 starts processing in step ST1. Then, in step ST2, the control section 201 resets the frame count TP indicating the time elapsed after switching to the transition attribute to 0, and moves to the processing in step ST3 for processing of the first picture (frame) after image switching.

[0143] In step ST3, the control unit 201 determines whether the ratio α is higher than the threshold RTh of the ratio of high brightness to the entire image, the ratio α being obtained from the statistical information SEI message as described above or calculated by the statistical information processing unit 205, in other words, the ratio α is the ratio of pixels whose pixel level exceeds the threshold level (TH_high) to the entire image. Here, the threshold RTh is preset by the receiving device 200.

[0144] In the case where the ratio α is determined to be higher than the threshold value RTh, the control section 201 proceeds to the processing in step ST4. In step ST4, it is determined whether the transition display period TTh, which is obtained from the statistical information SEI message or calculated as described above by the statistical information processing section 205, is greater than the frame count TP. Note that it is assumed that the ratio α used in step ST3 is obtained for each picture (frame), but the transition display period TTh used in step ST4 is fixed to the transition display period TTh obtained for the first picture (frame) after image switching.

[0145] When the transition display period TTh is determined to be greater than the frame count TP, the control unit 201 sets the electro-optical conversion attribute applied to the current picture (frame) by the electro-optical conversion unit 207 as the transition attribute. In step ST5, when there are multiple transition attributes, multiple levels of transition attributes are sequentially applied to each period into which the transition display period TTh is divided.

[0146] After the processing in step ST5 , the control section 201 increases the frame count TP in step ST6 , and then returns to step ST3 to perform control processing similar to the above-described control processing for processing the next picture (frame).

[0147] In addition, in step ST3, in the case where the ratio α is determined to be not higher than the threshold value RTh, or in step ST4, in the case where the transition display period TTh is determined to be not greater than the frame count TP, the control section 201 transfers to the processing in step ST7. In step ST7, the control section 201 changes the electro-optical conversion properties applied by the electro-optical converter 207 to the current and subsequent pictures (frames) to normal HDR electro-optical conversion properties, and ends the processing in step ST8.

[0148] Will briefly describe Fig.14 The operation of the receiving device 200 shown in FIG. The receiving section 202 receives a broadcast stream (MPEG-2 TS, MMT, MP4 (ISO MMFF) or the like) from the transmitting device 100 through broadcasting or communication, and outputs the broadcast stream directly or through the recording and reproducing section 202a.

[0149] The broadcast stream output from the receiving device 200 is provided to the container decoder 203. The container decoder 203 extracts the video stream from the broadcast stream. In addition, the container decoder 203 extracts various types of information contained in the layer in the container and sends the information to the control section 201. In the case where the layer in the container includes information on the electro-optical conversion transition property, the information is also extracted and sent to the control section 201.

[0150] The video stream extracted by the container decoder 203 is supplied to the video decoder 204. The video decoder 204 applies a decoding process to the video stream to obtain HDR image data.

[0151] In addition, the video decoder 204 extracts a parameter set or SEI message for each access unit included in the video stream, and transmits the parameter set or SEI message to the control section 201. As the SEI message thus extracted, the video stream includes a statistical information SEI message (see Fig.12 (a)) or transition transfer function SEI message (see Fig.13 (a)).

[0152] The HDR image data obtained by the video decoder 204 is supplied to the statistical information processing section 205 and the YCbCr / RGB conversion section 206. In the case where pixel statistical information (information on the ratio α of pixels each having a pixel level exceeding a threshold level (TH_high) to the entire image) and information on the transition display period TTh cannot be acquired from the statistical information SEI message, the statistical information processing section 205 processes the image data to calculate these information and transmits the information to the control section 201.

[0153] The YCbCr / RGB conversion section 206 converts the HDR image data obtained by the video decoder 204 from the YCbCr / RGB (brightness and color difference) domain to the RGB domain. After conversion into the RGB domain, the image data is provided to the electro-optical conversion section 207. The electro-optical conversion section 207 applies the electro-optical conversion attribute to the image data to obtain display image data. Then, the display device 208 displays an image based on the display image data.

[0154] Under the control of the control section 201, the electro-optical conversion section 207 normally applies a normal HDR electro-optical conversion property (HDREOTF), but in the case where image switching is performed by nonlinear reproduction (such as channel switching, system activation, random access, and CM / program switching), a transition property (TRTF) is applied during a transition display period (TTh) after the switching to keep the brightness level of the displayed image lower than the normal level (see Figure 2 and Figures 5 to 8 ).

[0155] Note that the above description of the receiving device 200 shows an example in which, in the case of switching images by non-linear reproduction (such as in channel switching, system activation, random access, or CM / program switching), the association with the non-switched image under the control of the conversion attributes performed by the electro-optical conversion unit 207 is not considered.

[0156] An example of control performed in consideration of association with non-switched images will be described. Fig.16 (a) shows the previous picture image (the image that is not switched), Fig.16 (b) shows the switched, current picture image. For example, the statistical information processing unit 205 sets common areas R1, R2, and R3 for each image, and calculates the ratio α of pixels whose pixel level exceeds the threshold level (TH_high) in each area of ​​the previous and current picture images (see the above equation (1)).

[0157] Then, the control section 201 determines whether the ratio difference between the ratio α of the previous picture and the ratio α of the current picture in each region is within the range Gc. Based on the determination result, the control section 201 controls the conversion attribute to be applied by the electro-optical conversion section 207.

[0158] Fig.17 The flowchart in FIG. 1 shows another example of a process for controlling the electro-optical converter 203 performed by the control section 201 in the case where image switching is performed by nonlinear reproduction. The nonlinear control section 201 starts processing in step ST10. Then, in step ST11, the control section 201 resets the frame count TP indicating the time elapsed after switching to the transition attribute to 0, and moves to the processing in step ST12 for processing the first picture (frame) after image switching.

[0159] In step ST12, the control section 201 makes a positive or negative determination on the condition that the ratio difference in the region R3 exceeds the range Gc and the current picture has a high ratio α. In the case of a positive determination, the control section 201 makes a positive or negative determination on the condition that the ratio difference in the region R2 exceeds the range Gc and the current picture has a high ratio α in step ST13. In the case of a positive determination, the control section 201 proceeds to the processing in step ST15.

[0160] In case of negative determination in step ST12 or step ST13, the control section 201 makes positive or negative determination in step ST14 on the condition that the ratio difference in region R1 exceeds the range Gc and the current picture has a high ratio α. In case of positive determination, the control section 201 proceeds to processing in step S15.

[0161] In step ST15, the control section 201 determines whether the transition display period TTh is greater than the frame count TP. Note that, it is assumed that the ratio α used in steps ST12, ST13, and ST14 is obtained for each picture (frame), but the transition display period TTh is fixed to the transition display period obtained for the first picture (frame) after image switching.

[0162] In the case where it is determined that the transition display period TTh is greater than the frame count TP, in step ST16, the control unit 201 changes the electro-optical conversion attribute applied to the current picture (frame) by the electro-optical conversion unit 207 to a transition attribute. In step ST16, in the case where there are multiple transition attributes, multiple levels of transition attributes are sequentially applied to each period into which the transition display period TTh is divided.

[0163] After the processing in step ST16 , the control section 201 increases the frame count TP in step ST17 , and then returns to step ST12 to perform control processing similar to the above-described control processing for processing the next picture (frame).

[0164] In addition, in the case of a negative determination in step ST14, or in the case that the transition display period TTh is determined to be not greater than the frame count TP in step ST16, the control section 201 shifts to the processing in step ST18. In step ST18, the control section 201 changes the electro-optical conversion properties applied by the electro-optical converter 207 to the current and subsequent pictures (frames) to normal HDR conversion properties. In step ST19, the control section 201 ends the processing.

[0165] Note that the above Fig.14 The receiving device 200 in the embodiment changes the electro-optical conversion attribute applied by the electro-optical conversion section 207 to a conversion attribute to change the display attribute during the transition display period to a transition display attribute in which the brightness level is kept lower than the normal level. However, by controlling the LED backlight of the display device 208, a similar transition display attribute can be achieved.

[0166] Fig.18 An example of the configuration of the receiving device 200A that realizes the transition display attribute by backlight control is shown. Fig.18 Zhongyu Fig.14 Components corresponding to those shown in FIG. 1 are denoted by the same reference numerals, and detailed descriptions of these components are omitted.

[0167] In the receiving device 200A, the electro-optical conversion section 207 obtains position information Po about each pixel having a pixel level exceeding a threshold level (TH_high) and targeting a transition attribute, and transmits the position information Po to the control section 201. The control section 201 controls the LED backlight portion 208a of the display device 208 to reduce the light emission level of the LED corresponding to the pixel at the position indicated by the position information Po so that the display attribute during the transition display period is changed to a transition display attribute in which the brightness level is kept lower than the normal level.

[0168] In this case, the control of the control section 201 is performed by replacing the above-mentioned control with control for reducing the light emission level of the LED corresponding to the pixel at the position indicated by the position information Po, for example. Fig.15 The control for changing the electro-optical conversion to the transient property is provided in step ST5 in the flowchart of FIG.

[0169] Note that the above-described backlight control for realizing the transitional display attribute may be performed alone, but may be used together with the control for changing the electro-optical conversion attribute to the transitional attribute.

[0170] As mentioned above, in Figure 1 In the illustrated transmission and reception system 10, the transmission device 100 inserts pixel statistics information, which is used to determine whether to switch the display attribute to the transition display attribute in which the brightness level is kept lower than the normal level during the transition display period when image switching occurs, into a video stream obtained by encoding image data, and the transmission device 100 transmits the resulting video stream. This enables the receiving side to save time and effort in calculating pixel statistics information, which is used to determine whether to switch the display attribute to the transition display attribute in which the brightness level is kept lower than the normal level during the transition display period when image switching occurs.

[0171] In addition, Figure 1 In the transmission and reception system 10 shown, when switching images, the receiving device 200 maintains the transition display attribute during the transition display period, switching the display attribute to a transition display attribute in which the brightness level is kept lower than the normal level based on the pixel statistics information about the image. Therefore, when image switching occurs, visual safety can be ensured.

[0172] <2. Modification example>

[0173] Note that the above embodiment shows an example of a transmission and reception system 10 including a transmission device 100 and a reception device 200, but no such limitation is imposed on the configuration of the transmission and reception system to which the present technology can be applied. The portion of the reception device 200 may include a set-top box and a monitor (display) connected together via a digital interface (multimedia interface) such as HDMI (High Definition Multimedia Interface). Note that "HDMI" is a registered trademark.

[0174] Fig.19 An example of the configuration of the transmission and reception system 10A is shown. The transmission and reception system 10A includes a transmission device 100, a set-top box (STB) 200-1 (200-1') and a monitor 200-2 (200-2'). The set-top box 200-1 (200-1') and the monitor 200-2 (200-2') are connected together via HDMI.

[0175] The sending device 100 and Figure 1 The transmitting device 100 in the transmitting and receiving system 10 shown (see Fig. 9 ) are the same, so the description of the transmitting device 100 is omitted. The set-top box 200-1 receives a broadcast stream (MPEG-2TS, MMT, MP4 (ISOBMFF) etc.) transmitted by broadcasting or communication, for example. The monitor 200-2 (200-2') displays the HDR image data transmitted by HDMI from the set-top box (STB) 200-1 (200-1').

[0176] Fig. 20 An example of the configuration of the set-top box 200 - 1 is shown. Fig. 20 Zhongyu Fig.14 and Fig.18 Components corresponding to the components shown in FIG. 2 are denoted by the same reference numerals. The set-top box 200-1 includes a control unit 201-1, a receiving unit 202, a container decoder 203, a video decoder 204, and an HDMI transmitting unit 209. The set-top box 200-1 includes Fig.18 The part of the receiving device 200A in the embodiment includes a receiving unit 202, a container decoder 203 and a video decoder 204.

[0177] The control unit 201-1 controls the operation of each part of the set-top box 200-1. The configuration and operation of the receiving unit 202, the container decoder 203 and the video decoder 204 are similar to those of Fig.18 The receiving unit 202, container decoder 203 and video decoder 204 in the receiving device 200A are described in detail, and descriptions of these components are omitted.

[0178] The HDMI transmission section 209 transmits the HDR image data obtained by the video decoder 204, the pixel statistical information obtained from the above-mentioned statistical information SEI message (information on the ratio α of pixels whose pixel level exceeds the threshold level (TH_high) to the entire image) (see Fig.12 (a)), information about the transition display period TTh and information about the electro-optical conversion transition properties and obtained from the above-mentioned transition transfer function SEI message (see Fig.13 (a)) is transmitted to monitor 200-2.

[0179] In this case, information about the ratio α used as pixel statistical information, information about the transition display period TTh, and information about the electro-optical conversion transition properties are inserted into the blanking period in the HDR image data for transmission. In this case, the newly defined transition display control HDMI information frame is used to transmit the information about the ratio α used as pixel statistical information and the information about the transition display period TTh. In addition, the newly defined transition transfer function HDMI information frame is used to transmit the information about the electro-optical conversion transition properties.

[0180] Fig.21 (a) shows an example of the structure (syntax) of the transition display control HDMI information frame, Fig.21 (b) shows the contents (semantics) of the main information in this structural example. The first three bytes in the information frame form a header part, in which a plurality of pieces of information including the information frame type, version number, and byte length of data bytes are arranged.

[0181] The 4-bit information "EOTF type" is located at bits 7 to 4 of data byte 1. The 4-bit information indicates the type of EOTF. For example, "1" indicates "ITU-R Rec. BT.709 (gamma)", "2" indicates "ITU-R Rec. BT.2100PQ", and "3" indicates "ITU-R Rec. BT.2100HLG".

[0182] The 16-bit information "threshold_level" is located in data byte 2 and data byte 3. The 16-bit information indicates a lower limit threshold value of a pixel level value of a target for statistical information, in other words, a threshold level (TH_high).

[0183] 8-bit information "high_level_target_ratio" is located in data byte 4. The 8-bit information indicates the ratio α of the target pixel for the transition attribute to the entire image. The ratio is multiplied by 100 to obtain a percentage value. In addition, 16-bit information "transition_period" is located in data byte 5 and data byte 6. The 16-bit information indicates the transition display period TTh expressed as a frame count value.

[0184] Fig. 22 (a) shows an example of the structure (syntax) of the transition transfer function HDMI information frame, and Fig. 22 (b) shows the contents (semantics) of the main information in this structural example. The first three bytes of the information frame form a header part, in which a plurality of pieces of information including the information frame type, version number and byte length of data bytes are arranged.

[0185] 8-bit information "number_of_transition_types" is located in data byte 1. The 8-bit information indicates the number of types of transition attributes. The information on the transition attribute is presented repeatedly so that the number of repetitions is equal to the number of types of the transition attribute. 4-bit information "transitionTF Type" is located in the seventh to fourth bits of data byte 2. The 4-bit information indicates the type of the transition attribute. For example, "1" indicates type 1, "2" indicates type 2, and "3" indicates type 3 (see Figure 3 and Figure 4 ).

[0186] The 16-bit information "minimum_level" is located in data byte 3 and data byte 4. The 16-bit information indicates the minimum input pixel level of the curve for which the target EOTF is changed (see Figure 3 and Figure 4 16-bit information "maximum_level" is located in data byte 5 and data byte 6. The 16-bit information indicates the maximum input pixel level of the curve for which the target EOTF changes (see Figure 3 and Figure 4 The maximum level M of the transmitted code value in .

[0187] The 16-bit information "trace_pivot_size" is located in data byte 7 and data byte 8. The 16-bit information indicates the number of points through which the trace transition attribute passes. The 16-bit information "input_level(j)" and the 16-bit information "output_level(j)" are presented repeatedly, so that the number of repetitions is equal to the number of points through which the trace transition attribute passes.

[0188] 16-bit information "input_level(j)" is located in data byte 9 and data byte 10. The 16-bit information indicates the input pixel level of the transition attribute. 16-bit information "input_level(j)" is located in data byte 11 and data byte 12. The 16-bit information indicates the output value of the transition attribute corresponding to the input level.

[0189] Description of data byte 13 and subsequent bytes is omitted. Data byte 13 and subsequent bytes are a repetition of data byte 9 to data byte 12, depending on "trace_pivot_size", and are also a repetition of data byte 2 to data byte 12, depending on "number_of_transition_types".

[0190] Fig.23 Shows the connection to Fig. 20 An example of the configuration of the monitor 200-2 of the set-top box 200-1 in FIG. Fig.23 Zhongyu Fig.14 and Fig.18 The monitor 200 - 2 includes a control section 201 - 2 , an HDMI receiving section 210 , a statistical information processing section 205 , a YCbCr / RGB conversion section 206 , an electro-optical conversion section 207 , and a display device 208 .

[0191] The control section 201-2 controls the operation of each part of the monitor 200-2. The HDMI receiving section 210 receives HDR image data, pixel statistics (information about the ratio α of pixels whose pixel level exceeds the threshold level (TH_high) to the entire image), information about the transition display period TTh, and information about the electro-optical conversion transition attribute from the set-top box 200-1 via the HDMI transmission path by communication conforming to HDMI. Each type of information is transmitted to the control section 201-2.

[0192] When the HDMI receiving section 210 fails to receive the information about the ratio α and the information about the transition display period TTh used as pixel statistical information, the statistical information processing section 205 processes the HDR image data received by the HDMI receiving section 210 to calculate the information about the ratio α and the information about the transition display period TTh. The statistical information processing section 205 transmits the calculated ratio α and the information about the transition display period TTh to the control section 20-2.

[0193] The YCbCr / RGB conversion section 206 converts the HDR image data obtained by the HDMI receiving section 210 from the YCbCr (brightness and color difference) domain to the RGB domain. The electro-optical conversion section 207 applies electro-optical conversion properties to the image data in the RGB domain resulting from the conversion of the YCbCr / RGB conversion section 206, thereby obtaining display image data. The display device 208 is, for example, a liquid crystal display (LCD), and displays an image based on the display image data.

[0194] Under the control of the control section 201-2', the electro-optical conversion section 207 normally applies a normal HDR electro-optical conversion property (HDREOTF), but in the case where image switching is performed by nonlinear reproduction (such as in channel switching, system activation, random access, and CM / program switching), a transition property (TRTF) is applied during a transition display period (TTh) after switching to keep the brightness level of the displayed image lower than the normal level (see Figure 2 and Figures 5 to 8 ).

[0195] In addition, the electro-optical conversion section 207 obtains position information Po about each pixel having a pixel level exceeding the threshold level (TH_high) and targeting the transition attribute, and transmits the position information Po to the control section 201-2. Then, the control section 201-2 controls the LED backlight section 208a of the display device 208 to reduce the light emission level of the LED corresponding to the pixel at the position indicated by the position information Po, so that the display attribute during the transition display period is changed to the transition display attribute in which the brightness level is kept lower than the normal level.

[0196] Note that the monitor 200-2 performs control of the electro-optical conversion attribute to the transition attribute and control for suppressing the backlight brightness level to reduce the brightness level of the display image to ensure visual safety during the transition display period, but may exclusively perform one of the control operations.

[0197] Fig.24 A configuration example of a set-top box 200 - 1 ′ is shown. Fig.24 Zhongyu Fig.14 , Fig.18 and Fig. 20 Components corresponding to the components shown in FIG. 2 are denoted by the same reference numerals. The set-top box 200-1 includes a control unit 201-1', a receiving unit 202, a container decoder 203, a video decoder 204, a statistical information processing unit 205, and an HDMI transmitting unit 209. The set-top box 200-1' includes Fig.18 The receiving unit 202, container decoder 203, video decoder 204 and statistical information processing unit 205 in the receiving device 200A.

[0198] The control unit 201-1' controls the operation of each part of the set-top box 200-1'. The configuration and operation of the receiving unit 202, the container decoder 203, the video decoder 204 and the statistical information processing unit 205 are similar to those of Fig.18 The receiving unit 202, container decoder 203, video decoder 204 and statistical information processing unit 205 in the receiving device 200A are described below and are not described.

[0199] The HDMI sending unit 209 transmits the HDR image data obtained by the video decoder 204, pixel statistical information (information about the ratio α of pixels whose level of each pixel exceeds a threshold level (TH_high) to the entire image), information about the transition display period TTh, and information about the electro-optical conversion transition properties to the monitor 200-2' via the HDMI transmission path through communication compliant with HDMI.

[0200] In this case, information about the ratio α, information about the transition display period TTh, and information about the electro-optical conversion transition properties used as pixel statistical information are inserted into the blanking period in the HDR image data, and then the HDR image data is transmitted. In this case, the newly defined transition display control HDMI information frame ( Fig.21 (a)) is used to transmit information about the ratio α used as pixel statistical information and information about the transition display period TTh. In addition, the newly defined transition transfer function HDMI information frame (see Fig. 22 (a)) is used to transmit information about the properties of the electro-optical conversion transition.

[0201] Fig.25 A configuration example of a monitor 200 - 2 ′ connected to a set-top box 200 - 1 ′ is shown. Fig.24 Zhongyu Fig.14 , Fig.18 and Fig.23 The monitor 200 - 2 ′ includes a control section 201 - 2 ′, an HDMI receiving section 210 , a YCbCr / RGB conversion section 206 , an electro-optical conversion section 207 , and a display device 208 .

[0202] The control section 201-2' controls the operation of each part of the monitor 200-2'. The HDMI receiving section 210 receives HDR image data, pixel statistics (information about the ratio α of pixels whose pixel level exceeds the threshold level (TH_high) to the entire image), information about the transition display period TTh, and information about the electro-optical conversion transition attribute from the set-top box 200-1' via the HDMI transmission path by communication conforming to HDMI. Each type of information is transmitted to the control section 201-2'.

[0203] The YCbCr / RGB conversion section 206 converts the HDR image data obtained by the HDMI receiving section 210 from the YCbCr (brightness and color difference) domain to the RGB domain. The electro-optical conversion section 207 applies electro-optical conversion properties to the image data in the RGB domain resulting from the conversion of the YCbCr / RGB conversion section 206, thereby obtaining display image data. The display device 208 is, for example, a liquid crystal display (LCD), and displays an image based on the display image data.

[0204] Under the control of the control section 201-2, the electro-optical conversion section 207 normally applies a normal HDR electro-optical conversion property (HDREOTF), but in the case where image switching is performed by nonlinear reproduction (such as in channel switching, system activation, random access, and CM / program switching), a transition property (TRTF) is applied during a transition display period (TTh) after switching to keep the brightness level of the displayed image lower than the normal level (see Figure 2 and Figures 5 to 8 ).

[0205] In addition, the electro-optical conversion section 207 obtains position information Po about each pixel having a pixel level exceeding the threshold level (TH_high) and targeting a transition attribute pixel, and transmits the position information Po to the control section 201-2'. Then, the control section 201-2 controls the LED backlight section 208a of the display device 208 to reduce the light emission level of the LED corresponding to the pixel at the position indicated by the position information Po, so that the display attribute during the transition display period is changed to a transition display attribute in which the brightness level is kept lower than the normal level.

[0206] Note that the monitor 200-2' performs control of the electro-optical conversion attribute to the transition attribute and control for suppressing the backlight brightness level to reduce the brightness level of the display image to ensure visual safety during transition display, but one of the control operations may be exclusively performed.

[0207] Furthermore, the present technology can be configured as follows.

[0208] (1) An image processing device comprising:

[0209] The control section, when switching the image, keeps the display attribute switched to a transition display attribute in which the brightness level is kept lower than a normal level during the transition display period based on pixel statistical information about the image.

[0210] (2) The information processing device according to (1) above, wherein:

[0211] The pixel statistics include information indicating a ratio of pixels exceeding a threshold level to the entire image.

[0212] (3) The information processing device according to (1) or (2) above, wherein:

[0213] The control unit utilizes the pixel statistical information obtained by processing image data.

[0214] (4) The information processing device according to any one of (1) to (3) above, wherein:

[0215] The control section utilizes information on the transition display period obtained based on the pixel statistical information.

[0216] (5) The information processing device according to (1) or (2) above, wherein:

[0217] The control section utilizes the pixel statistical information or information on the transition display period extracted from the encoded image data.

[0218] (6) The information processing device according to any one of (1) to (5) above, wherein:

[0219] As the transition display attribute, there are a plurality of levels of transition display attributes, and

[0220] The control section sequentially applies the plurality of levels of transition display attributes during the transition display period.

[0221] (7) The information processing device according to any one of (1) to (6) above, wherein:

[0222] The control section maintains the electro-optical conversion attribute applied to the image data as the transition attribute during the transition display period.

[0223] (8) The information processing device according to any one of (1) to (7) above, wherein:

[0224] The control section maintains a brightness level of a backlight of the display device lower than a normal level during the transition display period.

[0225] (9) An image processing method, comprising:

[0226] When the image is switched, the display attribute is switched to a transition display attribute in which the brightness level is kept lower than a normal level during the transition display period by the control section based on pixel statistical information about the image.

[0227] (10) A sending device comprising:

[0228] a transmitting unit that transmits a video stream obtained by encoding the image data, and

[0229] An information inserting section inserts pixel statistical information into the video stream, the pixel statistical information being used to determine whether to switch the display attribute to a transition display attribute in which a brightness level is kept lower than a normal level during a transition display period when switching images.

[0230] (11) The transmitting device according to (10) above, wherein:

[0231] The pixel statistics include information indicating a ratio of pixels exceeding a threshold level to the entire image.

[0232] (12) The transmitting device according to (10) or (11) above, wherein:

[0233] The information inserting section also inserts information about the transition display period into the video stream.

[0234] (13) The transmission device according to any one of (10) to (12) above, wherein:

[0235] The information inserting section also inserts into the video stream an electro-optical conversion transition attribute applied to moving image data during the transition display period.

[0236] (14) The transmitting device according to (13) above, wherein:

[0237] The information on the electro-optical conversion transition property includes table information corresponding to a variation range of a normal electro-optical conversion property.

[0238] (15) The transmitting device according to (13) or (14) above, wherein:

[0239] There are multiple levels of transition attributes.

[0240] (16) A sending method, comprising:

[0241] The video stream obtained by encoding the image data is transmitted by the transmitting unit, and

[0242] The pixel statistics information is inserted into the video stream by the information inserting section, the pixel statistics information being used to determine whether to switch the display attribute to the transition display attribute in which the brightness level is kept lower than the normal level during the transition display period when the image is switched.

[0243] (17) A sending device comprising:

[0244] A digital interface unit transmits pixel statistics information together with the image data, the pixel statistics information being used to determine whether to switch the display attribute to a transition display attribute in which the brightness level is kept lower than a normal level during a transition display period when switching images.

[0245] (18) The transmitting device according to (17) above, wherein:

[0246] The digital interface portion also transmits information regarding electro-optical conversion transition properties applied to the image data during the transitional display period.

[0247] (19) The transmitting device according to (18) above, wherein:

[0248] The information on the electro-optical conversion transition property includes table information corresponding to a variation range of a normal electro-optical conversion property.

[0249] (20) A receiving device comprising:

[0250] The digital interface receives pixel statistics information together with the image data, the pixel statistics information being used to determine whether to switch the display attribute to a transition display attribute in which the brightness level is kept lower than a normal level during the transition display period when the image is switched.

[0251] The main feature of the present technology is that when switching images by nonlinear reproduction, visual safety can be ensured when switching images by maintaining the display attribute switched to the transition display attribute in which the brightness level is kept lower than the normal level during the transition display period (see Figure 2 , Figure 3 , Fig.14 and Fig.15 ).

[0252] [reference numerals list]

[0253] 10.10A sending and receiving system

[0254] 100 Sending device

[0255] 101 Control Department

[0256] 102 Photoelectric conversion unit

[0257] 103RGB / YCbCr conversion unit

[0258] 104 Statistical Information Processing Department

[0259] 105 Video Encoder

[0260] 106 Container Encoder

[0261] 107 Sending Department

[0262] 200, 200A receiving equipment

[0263] 200-1, 200-1' set-top box

[0264] 200-2, 200-2' monitor

[0265] 201, 201-1, 201-1', 201-2, 201-2' control unit

[0266] 202 Receiving Department

[0267] 202a Recording and reproduction unit

[0268] 203 Container Decoder

[0269] 204 Video Decoder

[0270] 205 Statistical Information Processing Department

[0271] 206YCbCr / RGB conversion unit

[0272] 207 Electro-optical conversion unit

[0273] 208 Display device

[0274] 208a LED backlight part

[0275] 209HDMI transmitter

[0276] 210HDMI receiving unit.

Claims

1. A receiving device, comprising: The circuit is configured as: Receive a group of pictures from a video stream; decoding the group of pictures to obtain image data of the group of pictures; as well as applying a transition display attribute to a first frame of the image data during a transition display period after a time of switching from a previous frame to a current frame in the video stream, the previous frame and the current frame not being consecutive frames in the video stream, the switching being a channel switch, wherein the first frame of the image data within the transition display period has a lower brightness than the brightness of the second frame of the image data after the transition display period by applying the transition display attribute, and The circuit is configured to apply normal display attributes specified according to control information included in the video stream on the second frame for display, and to transition the transition display attributes to the normal display attributes immediately after the transition display period.

2. The receiving device according to claim 1, comprising: A display comprising a backlight, wherein the circuit is configured to maintain a brightness level of the backlight of the display below a normal level during the transitional display period.

3. The receiving device according to claim 1, wherein: The control information is included in a video usability information (VUI) area of ​​the video stream.

4. The receiving device according to claim 1, wherein: The circuitry is configured to apply the transitional display attributes based on pixel statistics contained in the video stream.

5. The receiving device according to claim 1, wherein: The circuit is configured to determine the transition display period based on pixel statistics contained in the video stream.

6. The receiving device according to claim 1, wherein: The circuit is further configured to receive metadata in the video stream, the metadata including information indicating the transition display attribute or the transition display period.

7. The receiving device according to claim 6, wherein: Information indicating the transition display attribute or the transition display period is included in a Supplemental Enhancement Information (SEI) message of the video stream.

8. The receiving device according to claim 6, wherein: Information indicating the transition display attribute or the transition display period is included in an information frame.

9. The receiving device according to claim 6, wherein: Information indicating the transition display attribute is included in a media presentation description (MPD).

10. The receiving device according to claim 1, wherein: A substantially black or grey frame is provided after the switching time.

11. A receiving method, comprising: Receive a group of pictures from a video stream; decoding the group of pictures to obtain image data of the group of pictures; as well as applying a transition display attribute to a first frame of the image data during a transition display period after a time of switching from a previous frame to a current frame in the video stream, the previous frame and the current frame not being consecutive frames in the video stream, the switching being a channel switch; and applying a normal display attribute specified according to control information included in the video stream on a second frame for display, and transitioning the transition display attribute to the normal display attribute immediately after the transition display period, Wherein, by applying the transition display attribute, the first frame of the image data within the transition display period has a brightness lower than the brightness of the second frame of the image data after the transition display period.

12. The receiving method according to claim 11, wherein: The control information is included in a video usability information (VUI) area of ​​the video stream.

13. The receiving method according to claim 11, comprising: The transitional display attributes are applied based on pixel statistics contained in the video stream.

14. The receiving method according to claim 11, comprising: The transition display period is determined based on pixel statistics contained in the video stream.

15. The receiving method according to claim 11, comprising: Metadata in the video stream is received, the metadata including information indicating the transition display attribute or the transition display period.

16. The receiving method according to claim 15, wherein: Information indicating the transition display attribute or the transition display period is included in a Supplemental Enhancement Information (SEI) message of the video stream.

17. The receiving method according to claim 15, wherein: Information indicating the transition display attribute or the transition display period is included in an information frame.

18. The receiving method according to claim 15, wherein: Information indicating the transition display attribute is included in a media presentation description (MPD).

19. A receiving device, comprising: The circuit is configured as: Receive a group of pictures from a video stream; decoding the group of pictures to obtain image data of the group of pictures; as well as processing the image data to determine a transitional display period following a switch time between a first group and a second group of the groups of pictures and determining pixel statistics, the switch being a channel switch, wherein, in response to the pixel statistical information, a first frame in the transitional display period has a brightness lower than a brightness of a second frame in the second group, wherein the first frame and the second frame are not consecutive frames in the video stream, and Wherein, a normal display attribute specified according to control information included in the video stream is applied to the second frame for display, and the transition display attribute is transitioned to the normal display attribute immediately after the transition display period.

20. The receiving device according to claim 19, wherein: A substantially black or grey frame is provided after the switching time.

Images