Source color volume information messaging

Abstract

To provide methods of communicating source color volume information in a coded bitstream using supplemental enhancement information (SEI) messaging.SOLUTION: The method includes: detecting whether a first SEI messaging variable (source_colour_volume_id) indicating an identification number (ID) of source color volume information is present; checking whether its value is within an allowable range; reading a further flag concerning persistence of the first variable across a bitstream; checking, via a second SEI messaging variable, whether metadata explicitly specifies a color volume actually occupied by source data content; and extracting a minimum luminance value, a maximum luminance value, and an average luminance value.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority based on U.S. Provisional Patent Application No. 62 / 427,677, filed on November 29, 2016, and U.S. Provisional Patent Application No. 62 / 404,302, filed on October 5, 2016, and incorporates all of their disclosure contents herein by reference. Technology

[0002] The present invention relates to images in general. More specifically, certain embodiments of the present invention relate to communicating and processing source color volume information.

Background Art

[0003] Background ITU - T Recommendation H.265 for "Video Coding" (also known as HEVC) describes the syntax for providing supplementary SEI and VUI information in the coded bitstream in "Supplemental enhancement information" (SEI) in Appendix D and "Video usability information" (VUI) in Appendix E, so that the decoder can better map the decoded samples to the display.

[0004] Along with MPEG / ITU standardization processes, the Society of Motion Picture and Television Engineers (SMPTE) also specifies numerous recommendations regarding the transmission of metadata concerning color volume information for both source video and target displays. For example, a set of documents in SMPTE ST 2094 (e.g., [5] and [6]) specify metadata for use in color volume conversion of video content. This metadata may vary from scene to scene or from frame to frame. For example, such metadata may help a decoder present high dynamic range (HDR) and wide color gamut (WCG) data on a display with a smaller color volume than the mastering display used to master the source image.

[0005] In this specification, the term “metadata” refers to any auxiliary information transmitted as part of an encoded bitstream and which helps the decoder render the decoded image. Such metadata may include, but is not limited to, color space information or color gamut information, predictive parameters, reference display parameters, and auxiliary signal parameters, as described herein.

[0006] While appendices D and E of H.265 address much of the metadata associated with color volumes, they do not address all of the metadata necessary for the most efficient display management of HDR content. Three proposals [2-4] were submitted at the Joint Working Group (JCT-VC) of the June 2016 Geneva Conference on Video Coding on how to describe content color volume information using SEI or VUI messaging. Some of these proposals were influenced by SMPTE ST.2094 [5], but to a very different extent.

[0007] In [2], a content-SEI message describing the actual color distribution of video content is proposed as a signal for the content color gamut in 2D. In VUI, the variable c is used to indicate the container color gamut instead of the true source color gamut. olour_primaries are used [1]. [3] Multiple primary expressions and spatial domains are proposed to be associated with specified source characteristics. [4] A content color volume SEI message is proposed to indicate the color volume occupied by the content. This uses a (x,y,Y) description of color coordinates and has slices of luminance Y, with each slice associated with a polygon. These proposals have many drawbacks, namely, they provide information that is of little use to most display manufacturers, they can add significant overhead, and the required computational overhead may be too large to generate. To improve existing encoding and decoding methods, the inventors have considered that improved techniques are needed to generate and transmit source color volume information.

[0008] The methods described in this section are explorable, but not necessarily methods that have been conceived or explored before. Therefore, unless otherwise indicated, none of the methods described in this section should be considered to qualify as prior art simply because they are described in this section. Similarly, unless otherwise indicated, any problem identified with respect to one or more methods should not be considered to have been recognized in any prior art based on this section. [Brief explanation of the drawing]

[0009] Brief explanation of the drawing In the accompanying drawings, which use the same reference numerals for similar components, certain embodiments of the present invention are illustrated without limitation.

[0010] [Figure 1] Figure 1 shows an example of processing for a video distribution pipeline according to one embodiment of the present invention. [Figure 2] Figure 2 shows an example of a "maximum" possible color volume plot for a video container format. [Figure 3A] Figure 3A shows an example of the source content color gamut within a container color volume. [Figure 3B] Figure 3B shows an example of 2D slices of the container color volume and source color volume at a specific luminance (Y) value. [Figure 3C] Figure 3C shows an example of 2D slices of the container color volume and source color volume at a specific luminance (Y) value. [Figure 4] Figure 4 shows an example of processing for extracting source color volume information from SEI messaging according to one embodiment of the present invention. [Modes for carrying out the invention]

[0011] Description of Embodiments This specification describes a method for transmitting source color volume information using SEI messaging. For convenience, numerous details are described below to enable a complete understanding of the invention. However, it will be evident that the invention can be implemented without these details. On the other hand, detailed descriptions of well-known structures and devices are omitted to avoid unnecessarily complicating, obscuring, or making the description of the invention difficult to understand.

[0012] overview The embodiments described herein relate to a method for conveying source color volume information using SEI messaging. In a decoder, a processor for extracting SEI messaging contains source color volume information in the input bitstream. The processor receives a source color volume identification messaging variable that identifies the presence of a color. The processor receives the first messaging variable as part of the source color volume information. If the first messaging variable matches a first predetermined value, the processor generates x and y chromaticity coordinates for one or more primary colors based on the source color volume information in the input bitstream. The processor generates minimum luminance, maximum luminance, and average luminance values ​​based on the source color volume information in the input bitstream. The processor receives a second messaging variable as part of the source color volume information, and if the second messaging variable matches a second predetermined value, the processor generates x and y chromaticity coordinates for one or more primary colors corresponding to the minimum luminance, maximum luminance, and average luminance values ​​based on the source color volume information.

[0013] Source Color Volume Messaging Example Figure 1 shows an example of a video distribution pipeline (100) processing, illustrating the various stages from video capture to video content display. A sequence of video frames (102) is captured or generated using an image generation block (105). The video frames (102) are either captured digitally (e.g., by a digital camera) or generated by a computer (e.g., using computer animation) to provide video data (107). Alternatively, the video frames (102) may be captured on film by a film camera. After appropriate editing (not shown), the film is converted to a digital format to provide video data (107).

[0014] Next, the video data (107) is fed to a processor in a block (110) for post-production editing. Post-production editing (110) includes adjusting or changing the color or brightness in specific areas of the image to enhance the image quality or achieve a particular look according to the filmmaker's intentions. This is sometimes referred to as "color timing" or "color grading." Other editing (e.g., scene selection and ordering, image cropping, addition of computer-generated visual effects, etc.) may be performed in the block (110) to produce the final version (112) of the production for distribution. During post-production editing (110), the video image is viewed on a reference display (125) (also referred to as a "target display" against which the studio optimizes the video).

[0015] In some embodiments, prior to video coding (120), the video content may be analyzed and source color volume metadata (119) may be extracted, for example, as specified in SMPTE ST 2094-1[5] or as defined later in the present invention. Such metadata may also define the characteristics of a target display (e.g., a reference display (125)) and color remapping information so that a downstream receiver can render the decoded data in the best possible manner.

[0016] Following post-production (110) and source color volume analysis (115), the final generated video data (117) and associated metadata (119) may be delivered in an appropriate color format (e.g., 10-bit YCbCr, ICtCp, etc. in 4:2:0) to an encoding block (120) for downstream distribution to decoding and playback devices such as television receivers, set-top boxes, and cinemas. In some embodiments, the encoding block (120) may include an audio encoder and a video encoder (such as audio and video encoders as defined by ATSC, DVB, DVD, Blu-ray, and other distribution formats) to generate an encoded bitstream (122). The encoded bitstream (122) is a single-layer video encoded bitstream. It can be represented by a stream or by a multilayer bitstream. For example, in a multilayer bitstream, the signal (122) may include a base layer (e.g., an SDR layer or a 10-bit HDR (HDR10) layer) and an enhancement layer. When the enhancement layer is combined with the base layer, it produces an HDR bitstream (e.g., a 12-bit HDR signal) with a higher dynamic range than the base layer alone. The signal (122), which is the output bitstream from the encoder (120), may also include metadata (119) and further encoding-related metadata such as predictive parameters and other data to help the decoder better reconstruct the HDR signal.

[0017] In a receiver, an encoded bitstream (122) is decoded by a decoding unit (130) to generate a decoded signal (132) and associated metadata (119). The receiver (or target) display (150) may have characteristics that are completely different from those of the reference (or target) display (125). For example, without limitation, the reference display (125) may be a 1,000 nit display, and the receiver display may be a 500 nit display. In that case, by using a display management module (140) to generate a display mapping signal (142), the dynamic range of the decoded signal (132) can be mapped to the characteristics of the receiver display (150). As used herein, the term "display management" refers to the processing (e.g., tone mapping and gamut mapping) necessary to map an input video signal with a first dynamic range (e.g., 1000 nits) to a display with a second dynamic range (e.g., 500 nits). The display management unit (140) may consider the metadata (119) to improve the quality of the output video on the display (150). For example, as shown in [7], by using information about the luminance range of the target (or reference) display (e.g., 125) and source data on the receiver, the dynamic range of the video content can be better mapped by the receiver display (e.g., 150).

[0018] Color volume information FIG. 2 shows an example of the "maximum" possible color volume of a given container format (e.g., BT.2020) (also referred to as the "container color volume"). Such a volume can be constructed by two-dimensional (2D) gamut primaries, white point chromaticity (e.g., D65), a maximum luminance value (e.g., Lmax = 4,000 nits), and a minimum luminance value (e.g., 0.005 nits). Such a plot shows the maximum possible color volume boundaries for all colors within the source video content.

[0019] In fact, as indicated by the darker "cloud" (305) in FIG. 3A or the darker regions (305) in FIGS. 3B and 3C, the source color volume of the source content (e.g., 112), which may be for a particular frame or even within the entire scene, may be significantly smaller than the maximum possible color volume (310). Since the actual color volume (305) has a very irregular shape, transmitting such source color volume information for each frame or the entire scene requires a lot of information. For example, in some embodiments, gamut information may be notified for a plurality of luminance values (e.g., at 0.1, 1, 10, etc.). Then, the question is how many of the most important luminance values there are and what they are. Also, not only the overhead on the encoded bitstream required for such information, but also the complexity of generating such content on the encoder and / or the complexity of reconstructing the color volume information on the decoder need to be considered.

[0020] It is important to convey the minimum and maximum luminance values in the source content, but As the inventors understand, it is also useful for the receiver to transmit the average luminance (or midpoint luminance). These three values ​​together can help generate a reasonable tone curve for display mapping. In this disclosure, we propose to transmit the following metadata to describe the source color volume: a) the maximum 2D color gamut occupied by the source (e.g., source color volume), b) the maximum, minimum, and average luminance of the source, and c) optionally, sliced ​​(2D) color gamuts for these three luminance values ​​(e.g., see Figures 3B and 3C). Since the white points of the container primary and source content primary are assumed to be the same, there is no reason to retransmit such information. This information can be updated as needed, for example, on a frame-by-frame or scene-by-scene basis. Figures 3B and 3C show examples of 2D slices of the source color volume (305) and container color volume (310) at a particular luminance (Y) value. In Figure 3B, the 2D slice is a 2D slice at Y=84 nits, and in Figure 3C, the 2D slice is a 2D slice at Y=246 nits. The chromaticity (rgb) triangles surrounding the source color volume (305) and within the container RGB space are given for illustrative purposes only. The encoder may choose to define smaller or larger such regions and transmit them to the receiver.

[0021] Table 1 shows an example of source color volume SEI messaging according to one embodiment, following the terminology and syntax of the H.265 specification. The description of primary colors follows the CIE 1931 (x,y) chromaticity coordinates for primary colors as defined in ISO 11664-1 (see also ISO 11664-3 and CIE 15), using red, green, and blue primary colors. Other types of primary colors may also be used, such as 4-polygon, 5-polygon, or 6-polygon, or other polygon-based primary color representations. For the largest actual color gamut in the source content, in one embodiment, but not limited to, the syntax is similar to the definition of the colour_primaries parameter (or variable) as defined in Section E.3.1 for Table E.3 of the H.265 specification. Current source content can reach the P3 color space, but it is likely that it will take some time to reach BT.2020 / 2010 color ("DCI-P3" is defined in SMPTE EG 432-1 and SMPTE RP 431-2). Therefore, Table E.3 may be used when the source color gamut is P3 or less, or equal to BT.2020 / 2010 primary colors. However, for sources with a color gamut greater than P3 but less than BT.2020 / 2010, explicit signaling of the color gamut may be required. Luminance values ​​are given in nits (cd / m²). 2 ) is specified using the absolute value of the unit. Alternatively, to save bits, the luminance value may also be encoded using a non-linear representation (for example, as a value encoded according to the inverse EOTF of SMPTE ST 2084). Color gamut information corresponding to the maximum, minimum, and average (intermediate) luminance values ​​is optional, allowing applications to reduce metadata overhead as desired.

[0022] In a preferred embodiment, 1) the source color volume metadata should describe the source color volume in its original form before any chroma or chroma preprocessing is performed. For example, the source color volume metadata should describe the source color volume before any chroma subsampling (e.g., from 4:4:4 to 4:2:0) or bit depth conversion (e.g., from 12b to 10b) is performed, because chroma subsampling or bit depth conversion alters the color volume information. 2) The source color gamut is typically different from the container primary colors. This is shown in Appendix E (e.g., Table E.3). 3) The source color volume is typically different from the mastering display color volume (which may be indicated by the mastering display color volume SEI message).

[0023] In one embodiment, the parameters (or variables) and coding semantics in Table 1 may be described as follows:

[0024] The `source_colour_volume_id` contains an identification number that can be used to identify the purpose of the source color volume. The value of `source_colour_volume_id` is between 0 and 2. 32 It is within the range of -2 or less. According to the application's decision, the source_colour_volume_id value will be 0-255 and 512-2 31 -1 may be used. The value of source_colour_volume_id is between 256 and 511 and 2 31 The above 2 32 Decoders below -2 are reserved for future use by ITU-T|ISO / IEC. Decoders are in the range of 256 to 511 or 2 31 The above 2 32 Ignore all color remapping information SEI messages that contain source_colour_volume_id values ​​in the range of -2 or less, and the bitstream will never contain such values.

[0025] The `source_colour_volume_cancel_flag` flag, when equal to 1, indicates that the source color volume SEI message cancels the duration of any preceding source color volume SEI message in the output order applied to the current layer. When `source_colour_volume_cancel_flag` is equal to 0, it indicates that the source color volume continues.

[0026] The `source_colour_volume_persistence_flag` specifies the persistence of source color volume SEI messages for the current layer. When `source_colour_volume_persistence_flag` is equal to 0, it specifies that the source color volume information applies only to the current picture.

[0027] Let picA be the current picture. When source_colour_volume_persistence_flag is equal to 1, it specifies that the source color volume persists in output order for the current layer until one of the following conditions is true. - A new coded layer video sequence (CLVS) for the current layer begins. - The bitstream is ending. -A picture picB in the current layer of an access unit containing a source color volume SEI message applicable to the current layer, which has the same source_colour_volume_id value, is output, such that PicOrderCnt(picB) is greater than PicOrderCnt(picA). Here, PicOrderCnt(picB) and PicOrderCnt(picA) are the PicOrderCnt values ​​of picB and picA immediately after the decoding process for the picture order count for picB is performed, respectively.

[0028] The source_colour_primaries have the same semantics as defined in Section E.3.1 for the colour_primaries syntax element, except that colour_primaries in Section E.3.1 notifies the container source primary colors, and source_colour_primaries notifies the primary colors actually occupied by the source content. If the value of source_colour_primaries is equal to 2, source_colour_primaries are explicitly specified by the syntax source_primaries_x[c] and source_primaries_y[c].

[0029] source_primaries_x[c] and source_primaries_y[c] are based on ISO 11664-1 (also ISO 11664-3 and CIE The normalized x and y chromaticity coordinates of the primary color component c of the source content are specified in increments of 0.00002, in accordance with the CIE 1931 specifications for x and y as specified in 15. When describing source content that uses the primary colors red, green, and blue, it is proposed that an index value c equal to 0 corresponds to the primary color green, a c equal to 1 corresponds to the primary color blue, and a c equal to 2 corresponds to the primary color red (see also Appendix E and Table E.3). The values ​​of source_primaries_x[c] and source_primaries_y[c] are in the range of 0 to 50,000.

[0030] max_source_luminance, min_source_luminance, and avg_source_luminance are 0.0001 candela / m². 2Specifies the nominal maximum luminance, nominal minimum luminance, and nominal average luminance of the source in nits. min_source_luminance must be less than avg_source_luminance, and avg_source_luminance must be less than max_source_luminance.

[0031] The `luminance_colour_primaries_info_present_flag` flag, when equal to 1, specifies that the syntax elements `luminance_primaries_x` and `luminance_primaries_y` exist, and when `luminance_colour_primaries_info_present_flag` is equal to 0, specifies that the syntax elements `luminance_primaries_x` and `luminance_primaries_y` do not exist.

[0032] luminance_primaries_x[i][c] and luminance_primaries_y[i][c] are CIE values ​​for x and y as specified in ISO 11664-1 (see also ISO 11664-3 and CIE 15). In accordance with the 1931 standard, the normalized x and y chromaticity coordinates of the primary color component c of source content at a given nominal luminance are specified in increments of 0.00002. When describing source content luminance, index values ​​0, 1, and 2 correspond to max_source_luminance, min_source_luminance, and avg_source_luminance, respectively. When describing source content using red, green, and blue primary colors, it is proposed that an index value c equal to 0 corresponds to the green primary color, c equal to 1 corresponds to the blue primary color, and c equal to 2 corresponds to the red primary color (see also Appendix E and Table E.3). The values ​​of source_primaries_x[c] and source_primaries_y[c] are in the range of 0 to 50,000.

[0033] Table 1 shows what is considered to be the minimum information necessary for a useful representation of the source color volume. In another embodiment, further details may be specified, such as a description of multiple primary colors[3] or primary colors of more than three slices of luminance (Y) (each slice associated with a polygon).

[0034] Table 1: Example of Source Color Volume SEI Messaging Syntax [Table 1]

[0035] Figure 4 shows an example of a process for extracting color volume information from a video source using SEI messaging according to one embodiment. First (405), the decoder detects whether a first SEI messaging variable (e.g., source_colour_volume_id) exists that indicates the identification number (ID) of the source color volume information. Next, if such a variable exists, the decoder may check whether its value is within an acceptable range (step 407). If the value is outside the acceptable range, the process terminates (step 409). If the value is within the acceptable range, in step (410), the decoder may also read further flags regarding whether the first variable persists across the bitstream, as shown in Table 1 (see, for example, the syntax elements for source_colour_volume_cancel_flag and source_colour_volume_persistence_flag). In step (412), via a second SEI messaging parameter (e.g., source_colour_primaries), the decoder may check whether the metadata explicitly specifies the color volumes actually occupied by the source data content. If true (e.g., source_colour_primaries=2), in step (420), the (x,y) chromaticity coordinates are read for each primary color (e.g., red, green, and blue); otherwise, in step (425), the decoder extracts the minimum luminance, maximum luminance, and average luminance values. Optionally, SEI messaging may also specify the (x,y) chromaticity coordinates corresponding to the minimum, intermediate, and maximum luminance values ​​of the primary colors defined above. In one embodiment, this may be indicated by a third parameter (e.g., luminance_colour_primaries_info_present_flag=1). If such information does not exist (step 430) The process is completed (409), and if present (step 435), the decoder extracts the (x,y) chromaticity coordinates for the primary colors for the minimum, intermediate, and maximum luminance values, respectively.

[0036] After extracting the source color volume information, the decoder may use the source color volume data during its display management process (e.g., 140). In one example, display management may include two steps: tone mapping and gamut mapping. Minimum luminance values, mid-luminance values, and maximum luminance values ​​may be used to generate a tone mapping curve, as described in [6-7]. The maximum RGB color gamut and sliced ​​RGB color gamut may be used to perform gamut mapping.

[0037] Examination of the active area In some embodiments, defining the active region as part of the metadata relating to the source color volume can be advantageous. For example, when video is encoded in letterbox format, encoders and decoders should not include black letterbox areas when calculating the luma and chroma properties (e.g., minimum luminance, maximum luminance, and average luminance) of each video frame. Experimental results have shown that considering the "framing" or "matting" (e.g., pillarboxing, windowboxing, and letterboxing) of frames in a video sequence can significantly improve the overall output picture quality. Letterbox detection can be implemented by the decoder, thereby reducing the notification overhead of defining the active picture region, but in some embodiments, such notification can be explicitly notified to support a low-computational complexity decoder. Table 2 shows an example of source color volume SEI messaging with active region notification according to one embodiment.

[0038] Table 2: Example of Source Color Volume SEI Message Syntax with Active Area Notification [Table 2]

[0039] Table 2 is a superset of Table 1 and considers two different semantics that define the active region. Semantics 1. In one embodiment, the active region is specified for the decoded picture before conformance window cropping and output. In this case, the active region parameter may be interpreted as follows:

[0040] When active_region_flag is equal to 1, it indicates that the active region offset parameter follows in the source color volume information SEI message. When active_region_flag is equal to 0, it indicates that the active region offset parameter does not exist.

[0041] active_region_left_offset, active_region_right_offset, active_region_top_offset, and active_region_bottom_offset specify the active rectangular region. If active_region_flag is equal to 0, active_ The values ​​of region_left_offset, active_region_right_offset, active_region_top_offset, and active_region_bottom_offset are assumed to be equal to 0.

[0042] The active region is defined using horizontal picture coordinates from SubWidthC*active_region_left_offset to pic_width_in_luma_samples-SubWidthC*active_region_right_offset+1) and vertical picture coordinates between SubHeightC*active_region_top_offset and pic_height_in_luma_samples-(SubHeightC*active_region_bottom_offset+1). The value of SubWidthC*(active_region_left_offset+active_region_right_offset) is less than pic_width_in_luma_samples, and the value of SubHeightC*(active_region_top_offset+active_region_bottom_offset) is less than pic_height_in_luma_samples. Semantics 2. In one embodiment, the active region offset value is defined relative to the final output picture for display. Therefore, conformance window parameters must be considered. In this case, the active region parameters may be interpreted as follows:

[0043] When active_region_flag is equal to 1, it indicates that the active region offset parameter follows in the source color volume information SEI message. When active_region_flag is equal to 0, it indicates that the active region offset parameter does not exist.

[0044] active_region_left_offset, active_region_right_offset, active_region_top_offset, and active_region_bottom_offset specify the active rectangular region. If active_region_flag is equal to 0, the values ​​of active_region_left_offset, active_region_right_offset, active_region_top_offset, and active_region_bottom_offset are assumed to be equal to 0.

[0045] The active region is defined using horizontal picture coordinates from active_region_left_offset+SubWidthC*conf_win_left_offset to CtbSizeY*PicWidthInCtbsY-SubWidthC*conf_win_right_offset-active_region_right_offset-1, and vertical picture coordinates between active_region_top_offset+SubHeightC*conf_win_top_offset and CtbSizeY*PicHeightInCtbsY-SubHeightC*conf_win_bottom_offset-active_region_bottom_offset-1.

[0046] The value of (active_region_left_offset+active_region_right_offset) is less than CtbSizeY*PicWidthInCtbsY-SubWidthC*(conf_win_right_offset+conf_win_left_offset), and the value of (active_region_top_offset+active_region_bottom_offset) is less than CtbSizeY*PicHeightInCtbsY-SubHeightC * (conf_win_bottom_offset + conf_win_top_offset) is less than this value.

[0047] The disclosures of each of the documents listed below are incorporated herein by reference. References [1]Rec.ITU-T H.265, “Series H:Audiovisual and Multimedia systems,Infrastructure of audiovisual services - Coding of moving video, High efficiency video coding,”ITU,Oct.2014. [2]HM Oh et al., “Content color gamut SEI message”, JCTVC-X0040, May 2016, Geneva, CH. [3]AM Tourapis, “Improvements to the Effective Color Volume SEI”, JCTVC-X0052, May 2016, Geneva, CH. [4] AK Ramasubramonian, “Content color volume SEI message”, JCTVC-X0052, May 2016, Geneva, CH. [5]SMPTE ST 2094-1:2016:“Dynamic Metadata for Color Volume Transform - Core Components,” SMPTE, May 18, 2016. [6]SMPTE ST 2094-10:2016:“Dynamic Metadata for Color Volume Transform - Application #1,”SMPTE,May 18,2016. [7] R. Atkins et al.,USPatent Publication US2016 / 0005349,“Display management for high dynamic range video.”

[0048] Computer system implementation examples Embodiments of the present invention may be implemented using a computer system, a system comprising electronic circuits and components, a microcontroller, a field-programmable gate array (FPGA) or other configurable or programmable logic device (PLD), an integrated circuit (IC) device such as a discrete-time or digital signal processor (DSP), or an application-specific IC (ASIC), and / or an apparatus comprising one or more such systems, devices, or components. The computer and / or IC may issue, control, or execute instructions relating to the transmission of source color volume information using SEI messaging as described herein. The computer and / or IC may calculate any of the various parameters or values ​​relating to the processing described herein. Image and video embodiments may be implemented using hardware, software, firmware, and various combinations thereof.

[0049] A particular aspect of the present invention includes a computer processor that executes software instructions for causing the processor to perform the method of the present invention. For example, one or more processors, such as a display, encoder, set-top box, or transcoder, may implement a method relating to conveying source color volume information using SEI messaging as described above by executing software instructions located in program memory accessible to the processor. The present invention may be provided in the form of a program product. This program product may include any non-temporary medium that stores a set of computer-readable signals, which, when executed by a data processor, include instructions for causing a data processor to perform the method of the present invention. The program product according to the present invention can take various forms. For example, this program product may include physical media such as magnetic data storage media including floppy disks and hard disk drives, optical data storage media including CD-ROMs and DVDs, and electronic data storage media including ROMs and flash RAM. The computer-readable signals on this program product may optionally be compressed or encrypted.

[0050] When referring to a component (for example, a software module, processor, assembly, device, circuit, etc.) in the above, the reference to that component (" Unless otherwise explicitly stated, any reference to a "means" should be interpreted as including, as equivalent to, any component that performs the function of the component (for example, is functionally equivalent), including components that are not structurally equivalent to the disclosed structures performing the functions described in the embodiments of the present invention described above.

[0051] Equivalents, extensions, substitutes, and others Examples of embodiments relating to the transmission of source color volume information using SEI messaging have been described above. Embodiments of the present invention have been described in this specification with reference to numerous specific details that may differ for each implementation. Accordingly, the sole and exclusive indicator of what the present invention is and what the applicant intends it to be is the set of claims arising from this application in the specific forms from which these claims arise, including any subsequent amendments. Any definitions expressed herein for any term contained in such claims shall determine the meaning of such term as used in the claims. Accordingly, no limitations, components, characteristics, features, advantages or attributes expressed herein shall in any way limit the scope of the claims. Accordingly, this specification and the drawings should be considered illustrative, not restrictive.

Claims

1. A method performed by a processor for extracting source color volume information of an input bitstream from associated metadata, The processor receives an input video bitstream and metadata including source color volume information for the input video bitstream. Decoding one or more pictures in the input video bitstream to generate a decoded picture, If the persistence metadata flag is set to 0, the source color volume information is applied only to the currently decoded picture. If a metadata flag indicating the presence of source primary color metadata is set, For one or more primary colors, the x-chromaticity coordinates and y-chromaticity coordinates that define the two-dimensional color gamut of the input video bitstream for each of the one or more primary colors are extracted from the metadata, Extracting a luminance value parameter, including an average luminance value, from the metadata, wherein, for one or more encoded pictures in the input video bitstream encoded in letterbox format, the average luminance value is for the active region of the one or more encoded video pictures in the input video bitstream encoded in letterbox format. A method that includes this.

2. The method according to claim 1, further comprising generating an output video signal based on the metadata for the decoded picture and the source color volume information.

Images