HK1228149B - Methods for creating and distributing art-directable continuous dynamic range video - Google Patents

Description

Method for generating and distributing art-directable continuous dynamic range video

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 62/169,465, filed June 1, 2015, which is incorporated herein by reference in its entirety.

Technical Field

The present disclosure relates generally to high dynamic range (HDR) video technology, and more particularly, some embodiments relate to methods for generating and distributing continuous dynamic range video.

Background Art

High dynamic range (HDR) is used to refer to content and displays that have higher illumination or brightness levels and/or better contrast than standard dynamic range (SDR) content and displays.

Summary of the Invention

According to various embodiments, systems and methods for generating and distributing video or image content graded for multiple displays having different dynamic ranges are disclosed. In one embodiment, generating CDR content includes receiving a source image and generating a continuous dynamic range image by defining the luminance of each pixel of the source image as a continuous function based on a minimum dynamic range and a maximum dynamic range. In an implementation of this embodiment, generating the continuous dynamic range image further includes grading the source image based on the minimum dynamic range and the maximum dynamic range. The source image can be a single image (e.g., a photograph) or a video frame corresponding to a video.

In an embodiment, a continuous dynamic range image can be compressed by approximating each of the continuous functions using a truncated polynomial series. In a specific implementation of this embodiment, the polynomial series is a Chebyshev polynomial series. In a further embodiment, the polynomial coefficients of the truncated polynomial series can be represented in an image-like format.

In another embodiment of the technology disclosed herein, a graphical user interface method for generating a continuous dynamic range image or video includes: displaying multiple graded versions of an image on one or more displays of a computer system, wherein each of the graded versions is graded for a different dynamic range display, and a control for modifying a continuous function that defines the luminance of a first group of pixels of the image as the continuous function based on a minimum dynamic range and a maximum dynamic range. The method further includes receiving user input at the computer system to actuate the control to modify the continuous function; and in response to receiving the user input actuating the control to modify the continuous function, the computer system displays the modified version of each of the multiple graded versions of the image on the one or more displays.

In yet another embodiment of the technology disclosed herein, a method for distributing continuous dynamic range video comprising video frames includes the steps of: distributing the following to each of a plurality of receivers having associated displays: a minimum dynamic range level for each of the plurality of video frames; a maximum dynamic range level for each of the plurality of video frames; and metadata defining the luminance of each pixel in each of the plurality of video frames as an approximation of a continuous function between the minimum and maximum dynamic ranges. In an implementation of this embodiment, the continuous dynamic range video is transmitted as an over-the-air broadcast television signal, as a satellite television network signal, or as a cable television network signal. Alternatively, the continuous dynamic range video can be transmitted by a content server on a computer network.

In yet another embodiment of the technology disclosed herein, a method for decoding a continuous dynamic range image for display on a display having an associated dynamic range includes the steps of: receiving an encoded continuous dynamic range image; decoding the continuous dynamic range image using a codec; and generating a specific dynamic range representation of the image based on the decoded continuous dynamic range image and the dynamic range of the display. In this embodiment, the received encoded continuous dynamic range image includes: a minimum dynamic range graded version of the image; a maximum dynamic range graded version of the image; and continuous dynamic range metadata corresponding to the image.

Other features and aspects of the disclosed method will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate features according to embodiments of the present invention as examples. This summary is not intended to limit the scope of the invention, which is solely defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

This patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

The invention will now be described in detail, in accordance with one or more different embodiments, with reference to the following drawings, which are provided for purposes of illustration only and merely depict typical or example embodiments of the invention.

FIG. 1 illustrates an example environment in which CDR video may be generated, encoded, and distributed according to the present disclosure.

FIG. 2 illustrates an example CDR video generation and encoding system that may be implemented in the environment of FIG. 1 .

FIG3 is an operational flow chart illustrating a method of generating, encoding, and distributing CDR video according to an embodiment of the present disclosure.

FIG4 is an operational flow diagram illustrating an example method of generating a CDR video according to the present disclosure.

FIG5 illustrates a representation of a dynamic range hull according to the present disclosure.

FIG6 illustrates an example implementation of an illumination path for a video frame according to the present disclosure.

7A illustrates an example video editing interface that may be used by artists to produce CDR videos according to the present disclosure.

7B illustrates an example video editing interface that may be used by artists to produce CDR videos according to the present disclosure.

FIG8 illustrates a process of obtaining a numerical illumination path according to the present disclosure.

9 is an operational flow diagram illustrating an example method of compressing and encoding CDR video in preparation for distribution in accordance with the present disclosure.

10 illustrates example approximations of functions by Chebyshev polynomials of different orders, according to the present disclosure.

FIG11 illustrates the first eight coefficient images of a video sequence frame according to an example embodiment of the present disclosure.

12 is an operational flow diagram illustrating a receiver-side method for encoding and displaying a received CDR video content stream according to the present disclosure.

FIG13 illustrates an example computing module that may be used to implement various features of the methods disclosed herein.

The drawings are not exhaustive and do not limit the disclosure to the precise forms disclosed.

DETAILED DESCRIPTION

The emergence of HDR displays with different dynamic ranges from multiple vendors has created some significant challenges for content production and distribution. Specifically, the production challenge is adapting HDR content to the many upcoming displays claiming peak luminance ranging from 800 to 4000 nits, as well as future HDR displays with different dynamic ranges. The simple approach of grading content for each specific display dynamic range does not scale well due to the additional manual labor required. Methods proposed in the literature, such as display adaptive tone mapping, can alleviate this problem, but do not allow for precise artistic freedom in the expression of brightness variations.

Another challenge with distributing HDR content is the task of efficiently encoding and transmitting a large number of HDR streams graded for different display dynamic ranges. Previous work has proposed efficiently distributing a single HDR stream as a residual signal to SDR content. However, this approach is not effective for applications in display landscapes where many HDR streams need to be transmitted simultaneously.

According to embodiments of the technology disclosed herein, novel systems and methods are disclosed for generating video or image content graded for multiple displays having different dynamic ranges. In embodiments, the generated content is "continuous dynamic range" (CDR) content—a novel representation of pixel-luminance as a function of the display's dynamic range. In these embodiments, the generation of the CDR content includes grading the source content for a minimum dynamic range and a maximum dynamic range, and obtaining the continuous dynamic range of the source content by defining the luminance of each pixel of an image or video frame of the source content as a continuous function between the minimum and maximum dynamic ranges.

In this way, content graded for all possible display dynamic ranges simultaneously can be produced at minimal expense. In these embodiments, a graphical user interface can be provided whereby the user specifies how pixel illumination changes for different dynamic ranges, thereby allowing the production of CDR videos or images with full artistic control.

In further embodiments of the technology disclosed herein, methods for compressing, encoding, and distributing the resulting CDR video are described. In these embodiments, the CDR video can be assigned 1) a maximum dynamic range level for the video; 2) a minimum dynamic range level for the video; and 3) metadata that defines the luminance of each pixel of each video frame as a polynomial series approximation of a continuous function between the minimum and maximum dynamic ranges.

As used herein to describe displays, the term "dynamic range" generally refers to the luminance range of a display, i.e., the range from the display's minimum luminance (i.e., "black level") to its peak luminance. As will be appreciated by those skilled in the art, luminance can be measured using any known system of units, such as the SI unit of candela per square meter (cd/m ² ) or the non-SI unit of nits.

As further used herein, the term "lumipath" refers to a function that represents the luminance value of a pixel as a function of the peak luminance of a target display.

Before describing the present invention in detail, it is useful to describe an example environment in which the present invention can be implemented. FIG1 illustrates one such example environment 100. In environment 100, source video 101 (e.g., video in a raw camera format) is generated and encoded (step 110) into continuous dynamic range video using a CDR video generation and encoding system 102. The source video may include a movie, a trailer, a clip from a series, a commercial, a video game cutscene, etc.

In an embodiment further described below, a user of the CDR video generation and encoding system 102 can utilize a graphical user interface (GUI) to specify how the pixel illumination of each video frame of the source video 101 changes for different dynamic ranges, thereby allowing the generation of CDR videos with sufficient artistic control over the presentation of the video for displays with different dynamic ranges.

After the CDR video is generated, at step 120, the CDR video is distributed to multiple receivers 121-123 for decoding and display (step 130). In the CDR-encoded source video, the pixel-luminance of each frame is defined as a function of the dynamic range. Accordingly, depending on the dynamic range of the display associated with the receiver 121-123, the receiver 121-123 can decode the CDR based on the dynamic range of the receiver's display (illustrated in Figure 1 by a rectangular pattern on the left side of the display). As illustrated in the specific environment 100, the distribution step 120 includes transmitting or transferring the CDR video to multiple television receivers (e.g., smart TV receivers) or monitor displays 121-123 via an electronic distribution network 115. In an alternative embodiment, the CDR video can be transmitted to other receivers capable of decoding and displaying the CDR video, such as smart phones, laptops, tablets, workstations, etc.

In various embodiments, the CDR video can be transmitted as an over-the-air broadcast television signal, a satellite television network signal, or a cable television network signal. Alternatively, the CDR video can be transmitted by a content server over a computer network. As will be appreciated by those skilled in the art, the electronic distribution network 115 can include any combination of communication media (e.g., a coaxial cable system, a fiber optic cable system, an Ethernet cable system, a satellite communication system, a cellular communication system, etc.). In further embodiments, the CDR video can be distributed using physical media (such as a solid-state drive, a magnetic tape, a cassette, a Blu-ray disc, or other fixed or removable storage media known in the art that can store video).

FIG2 illustrates an example CDR video generation and encoding system 102 that can be implemented in environment 100. In various embodiments, system 102 can be any computing system (workstation, laptop, smartphone, etc.) configured to receive source video and generate CDR video that can be adapted to multiple different displays with different dynamic ranges. As illustrated, system 102 includes a connection interface 131, a memory 132 for storing a CDR video generation application 133 and source video 101, a processor 134, and one or more displays 135. Connection interface 131 can connect system 102 to a content distribution network (e.g., network 115) using a wireless network connection (such as a local area network connection, a cellular network connection, a satellite network connection, etc.). In addition, the connection interface can include a physical interface for transferring and receiving information, such as a USB interface.

Processor 134 executes a CDR video generation application 133 that can provide artists with a graphical user interface for customizing video content for displays with different dynamic ranges. In such embodiments, the artist can specify how the pixel illumination of different regions of each video frame of source video 101 should change for different dynamic ranges. In implementations of these embodiments described further below, display 135 displays multiple dynamic range versions of the video frame and various user controls for controlling the pixel illumination of each video frame. In some embodiments, CDR video generation application 133 can be integrated as part of an animation application, a video editing application, an imaging application, a video game design application, or some combination thereof.

In further embodiments, processor 134 may compress and encode the generated CDR video (eg, via CDR video generation application 133) in preparation for distribution using system 102 or another distribution device.

Although the example environment 100 is described with respect to the generation, encoding, and distribution of CDR videos, it should be noted that in other embodiments, the present invention may be implemented in an environment focused on the generation and distribution of CDR images, such as photographs, computer-generated images, etc. As will be appreciated by those skilled in the art, the environment 100 may be suitable for the generation, encoding, and distribution of CDR images.

FIG3 illustrates a method 200 for generating, encoding, and distributing CDR video according to an embodiment of the technology disclosed herein. The method 200 takes a source video 201 as input and outputs a CDR video comprising content graded for all possible display dynamic ranges simultaneously. The distributed CDR video comprises an encoded minimum dynamic range level 207 of the video, an encoded maximum dynamic range level 208 of the video, and encoded metadata 209 that can be used by the receiving display to adapt the received CDR video to its dynamic range.

The method 200 will be described in conjunction with Figures 4 and 9, which illustrate a specific method for generating a CDR video (220) and compressing and encoding the generated CDR video (230). In various embodiments, some or all of the process operations of the method 200 (e.g., CDR video generation, compression, and encoding, but not distribution) can be implemented by the system 102 using the CDR video generation application 133.

Method 200 begins at operation 210 by receiving source video 201. In embodiments, the received source video can be in a raw camera format (e.g., source video for a movie, a TV series segment, a commercial, etc.) or a computer-generated source video (e.g., source video for an animated movie, a video game, etc.). For example, the source video can be received from a studio after a scene is filmed for a movie or from a computer graphics artist after a scene is produced for an animated film. In various embodiments, the dynamic range of the source video can be arbitrary. In a specific embodiment, the source video can include high dynamic range (HDR) content with up to 14 f-stops.

After receiving source video 201, a CDR video is generated at operation 220. FIG4 illustrates an example method 220 for generating CDR video. At operation 211, source video content 201 is graded for minimum and maximum target dynamic ranges, thereby generating content 202 graded for the minimum dynamic range and content 203 graded for the maximum dynamic range. In an embodiment, the grading process includes defining the brightness and color of the source video for the maximum and minimum dynamic ranges. During, before, or after the grading process, a "dynamic range hull" can be determined for the content of source video 201. Because the dynamic range continuum contained by the CDR video is a superset of the dynamic ranges of all target displays, the dynamic range hull defines the dynamic range continuum between the minimum and maximum dynamic ranges.

FIG5 illustrates a representation of a dynamic range master. As illustrated, the minimum dynamic range is defined by the minimum peak luminance (b) and maximum black level (d) among a set of all target display dynamic ranges. Similarly, the maximum dynamic range is defined by the maximum peak luminance (a) and minimum black level (c) among the set of all target display dynamic ranges. In various embodiments, the system 102 can determine a dynamic range master based on parameters such as the type of content of the source video 102 (e.g., a film, a TV clip, a TV commercial, etc.), a list of known target display dynamic ranges, and other parameters.

For example, consider a scenario where the lowest peak luminance is 100 nits, the highest peak luminance is 4000 nits, the minimum black level is 0.01 nits, and the maximum black level is 0.1 nits for multiple target displays. In this example, the minimum dynamic range would be defined by 0.1 nits to 100 nits, while the maximum dynamic range would be defined by 0.01 nits to 4000 nits. Similarly, the most highly rated content would target a display with a peak luminance of 4000 nits and a black level of 0.01 nits, while the least highly rated content would target a display with a peak luminance of 100 nits and a black level of 0.1 nits.

Subsequently, at operation 212, a CDR video may be generated by defining the luminance of each pixel of each frame of the source video as a continuous function based on the minimum and maximum dynamic range levels 202, 203. In these embodiments, the CDR video may store a dynamic range function for each pixel, as opposed to conventional methods that store a scalar luminance value for each pixel. In particular embodiments, a "luminance path" function that represents the luminance value of a pixel as a function of the peak luminance of the target display may be used and stored at each pixel.

FIG6 illustrates an example embodiment of an illumination path for a video frame 500 including pixels 501-503. As shown, each pixel 501-503 of video frame 500 has an associated illumination path function 501A-503A that defines the illumination of the pixel based on the peak display illumination of the target display. In this example embodiment, a minimum dynamic range 510 and a maximum dynamic range 530 define illumination path functions 501A-503A. Dynamic range 520 corresponds to an intermediate dynamic range display. For pixel 501, as the peak display illumination increases, the pixel illumination does not increase significantly, indicating a darker area of video frame 500. In contrast, for pixels 502 and 503, the pixel illumination increases sharply near the center of the peak display illumination and then stabilizes. As will be appreciated by those skilled in the art, in various embodiments, the shape of illumination path functions 501A-503A can be modified to adapt the presentation of video content to different displays.

In an embodiment, the illumination path for each pixel can be user-defined using an interactive video editing interface provided by the CDR video generation application 133. Figures 7A-7B illustrate a specific embodiment of a video editing interface that can be used by a user of the system 102 to define the illumination path for each pixel of each video frame. As illustrated in this specific embodiment, a first SDR display (illustrated by Figure 7A) provides an interface 600 that includes controls (e.g., buttons, toggles, sliders, navigation components, etc.) for illumination paths for different video frames defined for different display dynamic ranges. A second HDR display (illustrated by Figure 7B) provides an interface 610 that allows the user to interactively visualize their edits for multiple dynamic ranges. It should be noted that although separate displays are illustrated for defining illumination paths and displaying edits for multiple dynamic ranges, in alternative embodiments, a single display (e.g., a large HDR display) can be used to perform both functions.

The interface 600 includes a control 605 for loading the rated videos into the system (e.g., by selecting a folder) in order to begin a rating session. As illustrated in this embodiment, the system is loaded with ratings for the extremes of the dynamic range subject (i.e., the smallest rated video and the largest rated video). In addition, the interface 600 includes a button control 601 for selecting the highest rated video or video frame (601), a button control 602 for selecting the lowest rated video or video frame 602, a slider control 603 for selecting a specific display with an associated dynamic range, and a slider control 604 for selecting a specific video frame.

Interface 610 provides a tiled interface for visualizing continuous dynamic range video across several dynamic ranges. In this example embodiment, six different windows allow the user to visualize how a video or video frame will look on six different dynamic range displays. By selecting a frame mode or video mode provided by control 609, the user can visualize how that particular frame or video clip will look. In this embodiment, the dynamic range is shown in increasing order from top left to bottom right, with top left window 611 showing the minimum dynamic range level and bottom right window 612 showing the maximum dynamic range level. Alternatively, in other embodiments, any number of windows and any dynamic range display order may be used.

In an embodiment illustrated by interface 600, cascaded masks can allow a user of application 133 to define the amount of editing in each video frame. As shown, the mask interface can provide controls 606 for selecting a specific mask, a display 607 of the selected mask, and controls 608 for modifying the illumination path function corresponding to the selected mask. In embodiments, the mask can be applied to contrasting regions of a video frame, specific regions of a video frame, or the entire video frame.

For example, consider the scene illustrated in Figure 7B. A first global mask can produce uniform masking for every pixel of the scene, including the face of the character of the cartoon and the background environment. Once the user is satisfied with the global mask, another mask (e.g., mask 607) can be applied to separate all or part of the character's face from the rest of the scene, allowing precise local control. For example, the character's face can be made brighter or darker relative to the environment across the entire dynamic range. Alternatively, the user can select to adjust the presentation of the character's face for a specific dynamic range (e.g., one or two target displays) relative to the entire dynamic range. As will be appreciated by those skilled in the art, considering the examples described above, masks can be used to change the highlights or shadows of different video frames across different dynamic ranges.

As shown in a specific embodiment of interface 600, a cubic polynomial spline interface control 608 allows a user to manually input an illuminance path and change the illuminance path by changing the shape of the displayed illuminance path function (e.g., by selecting a control point on the curve and dragging the mouse). However, in other embodiments, other suitable interfaces known in the art for defining and changing continuous functions (e.g., higher order polynomial spline interfaces) may be provided. It should also be noted that although the specific example of Figures 7A-7B is described with respect to using an illuminance path function to define the illuminance of pixels across a dynamic range body, in other embodiments, other suitable continuous functions may be used to define the illuminance of pixels based on minimum and maximum dynamic range levels. It should also be noted that in alternative embodiments, the illuminance path function may be pre-defined and used to generate CDR video based on minimum and maximum levels without relying on any user interaction.

In an embodiment, a function defining the luminance of each pixel of each frame (e.g., a luminance path) can be mathematically defined as follows. First, the minimum and maximum levels 202, 203 can be represented as 1 _α and 1 _β , respectively. The minimum and peak luminances of 1 _α are represented as η _α and π _α , respectively, and the minimum and peak luminances of 1 _β are represented as η _β and π _β , respectively. The function that specifies how the pixel luminance changes across the dynamic range of the subject can be defined by formula (1):

It associates with each pixel p and dynamic range (η,π), a unique luminance value h ^p (η,π), where h p is the luminance of pixel p for the minimum level and h p is the luminance of pixel p for the maximum level. Accordingly, formula (1) maps the luminance of a pixel within any target dynamic range of the dynamic range subject to a value between the actual pixel luminance values in the minimum and maximum levels.

To reduce the computational complexity and amount of data required to generate these functions, the domain can be restricted to [π _α ,π _β ], and the associated minimum illumination for any π∈[π _α ,π _β ] can be defined by formula (2):

Following equation (2), the dynamic range of interest can be defined by . Therefore, the luminance path that represents the luminance value of a pixel as a function of the peak luminance pi of the target display can be defined by equation (3):

where _πα and _πβ are the peak illuminances corresponding to the maximum and minimum dynamic ranges.

As mentioned in the example of Figures 7A-7B, the user can select a desired image region by utilizing a mask and adjusting the illumination path by changing the control points of the cubic polynomial spline interface. More generally, the user's use of a mask to define the illumination path can be mathematically defined as follows. Formally, given a series of image masks _Mj with values, the user can manually specify a function _kj : [ _πα , _πβ ] → [ _πα , _πβ ] using the user interface. When applied to each pixel, the function is adjusted by the mask at each pixel location and is obtained as shown in Equation (4):

Formula (4) defines a blend between an artist's defined curve and a linear curve based on the weights specified by the mask, allowing for smoothly changing edits. Thus, by employing n masks and specifying n such functions, the corresponding illumination path ^gp can be obtained by applying all functions in sequence (based on the hierarchy of layers) and scaling the results as shown by Formula (5):

where the luminance path is the desired curve defining the luminance of pixel p for any display with a maximum luminance between the two analyzed limits. FIG8 illustrates this process of obtaining the numerical luminance path as defined by equations (4) and (5). As shown, the luminance paths entered by the artist are averaged using a linear function according to the weights specified in the user interface and then concatenated to obtain the final per-pixel luminance path ^gp .

As will be appreciated by those skilled in the art, since there is no restriction on how the input levels of the video frame are obtained, any number of pixel-level masks for region selection can be used as long as the spatial correspondence of the pixels is maintained. Furthermore, the illumination path or other function can be precisely defined using any number of control points, thereby allowing significant artistic freedom during operation 220.

After the CDR video is generated at operation 220, the CDR video in its original format is represented for each frame f by: (1) an image with the minimum dynamic range classification (e.g., ); 2) an image with the maximum dynamic range classification (e.g., ); and 3) metadata including a continuous dynamic range function (e.g., luminance path g ^p,f ) for each pixel of the frame. In an embodiment, the original format of this data occupies a large amount of data. Accordingly, at operation 230 of method 200, the CDR video can be compressed and encoded in preparation for distribution.

9 illustrates an example method 230 of compressing and encoding CDR video in preparation for distribution. As described further below, method 230 may be used in embodiments to provide a representation of the CDR function for each pixel that is data efficient and visually lossless compared to the original CDR video.

Method 230 begins at operation 231, where the CDR function corresponding to each pixel is approximated using a polynomial series that is truncated after a certain number of coefficients. Accordingly, the resulting representation of each CDR function is a finite set of coefficients (i.e., a vector of coefficients) with respect to a polynomial basis. In a preferred embodiment, based on a model of the human visual system, the polynomial series is truncated at a point where the resulting output is visually lossless.

In the embodiments described further below, the polynomial series is a truncated Chebyshev series. In these embodiments, the use of Chebyshev polynomials may be desirable because i) they minimize Runge's phenomenon when approximating the time interval, which is important because in practice most displays are located near the minimum end of the dynamic range of interest; ii) they can be calculated numerically quickly; and iii) the error of the approximated function compared to the original function can be easily estimated based on the coefficients, thereby providing a stopping point. However, other suitable polynomial series known in the art may be used.

After approximating the CDR function using a finite set of coefficients having a polynomial basis, the polynomial coefficients are represented in an image format at operation 232, which allows a video codec to be applied to the data. For example, in one embodiment, the polynomial coefficients can be reconstructed into a monochrome video sequence. In embodiments, the representation of the polynomial coefficients in an image format can depend on the video codec (e.g., MPEG-4, H.264, etc.) that is subsequently used to encode the data.

Thereafter, at operation 233, the coefficient image (i.e., the polynomial coefficients in the image data format) can be encoded using a corresponding video codec (such as MPEG-4 or H.264), thereby providing additional compression and improving the data bit rate. In addition, at operation 233, the minimum dynamic range graded content 202 and the maximum dynamic range graded content 203 can be compressed and encoded using a video codec known in the art for compressing LDR and HDR content (e.g., MPEG format). In an embodiment, the content 202 and 203 can be jointly and non-independently encoded using mutual redundancy between the two signals. For example, in a specific embodiment, the two contents can be encoded as a base layer and an enhancement layer using a scalable video coding (SVC) method known in the art. Alternatively, in other embodiments, the minimum dynamic range graded content 202 and the maximum dynamic range graded content 203 can be encoded separately (e.g., using H.264).

In an embodiment, the mathematical implementation of the method 230 using the aforementioned illuminance path g ^p,f can be performed as follows. The human visual system can be modeled using a threshold-intensity (tvi) function that calculates an approximate threshold illuminance, taking into account the level of illuminance adaptation _La . The tvi function can be calculated by finding the peak contrast sensitivity at each illuminance level as shown in Equation (6):

where CSF is the contrast sensitivity function and is the adapted illuminance for pixel p. In this embodiment, it is assumed that the human eye can fully adapt to a single pixel p.

Considering the illumination path gp ^,f , if it satisfies, that is, the deviation is less than the threshold calculated by the model of the human visual system, then it can be approximated by a truncated Chebyshev series in a visually lossless way at a given pixel. The truncated Chebyshev series can be expressed by formula (7):

where _ψk (x) is the kth Chebyshev polynomial, is the corresponding Chebyshev coefficient at pixel p in frame f, and _Np ,f is the minimum degree required to obtain an error less than . This defines a visually lossless approximation to ^gp,f determined by Np _,f + 1 coefficients K,.

To compute the Chebyshev series, the domain and range of all illumination paths are scaled so that they all lie in the Chebyshev domain g ^p,f :[-1,1]→[-1,1]. Since each basis polynomial ψ _k (x) has a domain and its range is also a subset of [-1,1], the total error of the approximation is bounded by the sum of the absolute values of the infinite remaining coefficients of the series. In an embodiment, the stopping criterion for the coefficients can be given by the sum of the absolute values of a small number of elements. For example, the series can be truncated when the absolute sum of the next three elements is below an allowed error threshold. An example of the approximation of functions of Chebyshev polynomials of different orders is illustrated by FIG10. The absolute value of the error between the original function and the reconstructed representation is shown in the bottom scale of FIG10.

After determining the Chebyshev coefficients for an approximate but visually lossless representation of the illumination path, the coefficients can be quantized and reconstructed into a monochrome video sequence. The maximum degree N:=max _p,f N _p,f and the set (for k>N _p,f ) can be calculated, which leads to the representation of the function described in formula (7) but with a fixed parameter N. Each illumination path is now specified by an n-tuple of formula (8):

To obtain an image-like representation, the tuples c ^p,f of all pixels of the frame are represented by coefficient matrices for 1 < k < N, which, by construction, have the same pixel resolution h × w as and. All entries of all matrices can then be uniformly quantized to a particular bit depth to obtain N matrices. In an embodiment, the bit depth can be selected based on the maximum bit depth for the image supported by the video codec used for compression. For example, in this example embodiment, the entries of all matrices can be quantized to 8-bit integers, as this corresponds to the maximum bit depth of the image supported for compression by the main profile of H.264.

Figure 11 illustrates the first eight coefficient images of a frame of a video sequence. As shown, the majority of the information is concentrated within the first few coefficients. The energy and variance in the coefficient image decrease rapidly with increasing coefficient exponents. Furthermore, the coefficients can have uniform values across large image regions. Accordingly, the information content of coefficient images and videos is often relatively limited compared to the images and videos themselves, making them very compressible.

Thereafter, a compressed representation of the illumination path may be obtained by storing: 1) an integer value representing the number N, 2) two floating-point values representing the minimum and maximum values used for bit depth (e.g., 8-bit) quantization, and 3) an encoded representation for the sequence of images for k=1,...,N, obtained by encoding the coefficient images using a video codec (e.g., H.264).

After video compression and encoding of the CDR video at operation 230, the output content includes encoded minimum dynamic range graded content 207, encoded maximum dynamic range graded content 208, and encoded CDR video metadata 209. Referring back to FIG3, the content can then be distributed at operation 240. In an embodiment, the CDR video content can be distributed as an over-the-air broadcast television signal, a satellite television network signal, or a cable television network signal. Alternatively, the CDR video can be transmitted by a content server over a computer network. In further embodiments, the CDR video content can be distributed using physical media (such as solid-state drives, magnetic tapes, audio cassettes, Blu-ray discs, etc.).

FIG12 illustrates a receiver-side method 700 for decoding and displaying received CDR video content. As illustrated, the received CDR content may include video-encoded minimum dynamic range hierarchical content 207, maximum dynamic range hierarchical content 208, and CDR video metadata 209. Although illustrated in FIG12 as having separate reference numerals, it should be noted that the received maximum dynamic range hierarchical content and minimum dynamic range hierarchical content may be jointly encoded (e.g., as a base layer and an enhancement layer based on SVC technology).

At operation 702, the received content is decoded using a suitable video compression codec (e.g., H.264, MPEG-4, etc.). For example, in a specific embodiment where the minimum-level rating content and the maximum-level rating content are jointly encoded as base and enhancement layers using the SVC codec, the content can be decoded using the SVC codec. Alternatively, in other embodiments, the minimum dynamic range rating content 202 and the maximum dynamic range rating content 203 can be decoded separately (e.g., using H.264). In one embodiment, the CDR video metadata 209 can be decoded using the same codec used to decode the content 207 and 208.

Then, at operation 704, the receiver generates a suitable dynamic range representation of the video 707 based on the decoded content and the known dynamic range 705 of the display that will display the content. As will be appreciated by those skilled in the art, the receiver can reconstruct the luminance path of each pixel based on the polynomial vector of coefficients and knowledge of the algorithm used to generate the CDR metadata (such as the polynomial series used to represent the luminance path function for each pixel of each frame). Thereafter, taking into account the decoded maximum and minimum grading images, the luminance path of each pixel of the decoded and reconstructed images, and the display dynamic range 705, the corresponding luminance path can be evaluated for each pixel of each image to define the luminance of the pixel for the display, thereby obtaining a suitable dynamic range representation of the video 707.

Although the methods described herein have initially been described with reference to the generation, compression, distribution, and reception of CDR video, those skilled in the art will recognize that they are equally applicable to the generation of CDR images (such as CDR photographs or computer-generated graphics). For example, in various embodiments, a CDR image can be generated by grading a source image for maximum and minimum dynamic range and defining the luminance of each pixel of the image as a continuous function based on the minimum and maximum dynamic range levels. As another example, the graphical user interface of Figures 7A-7B can be adapted for the generation of CDR images by allowing an artist to simultaneously display and modify multiple dynamic range graded versions of a particular image (e.g., by adding a new mode 609 for the image or utilizing an existing frame mode).

Similarly, in various embodiments, a CDR image can be compressed by approximating the CDR function corresponding to each pixel of the image using a polynomial series that is truncated after a certain number of coefficients. Furthermore, the compressed CDR image can be encoded using a suitable codec. Furthermore, the encoded CDR image can be distributed to a receiver that encodes and displays the image using a suitable codec.

Figure 13 shows an exemplary computing module, which can be used to implement the different features of the systems and methods disclosed herein. As used in this article, the term module can describe a given functional unit that can be executed according to one or more embodiments of the present application. As used in this article, a module can be implemented in any form of hardware, software, and a combination thereof. For example, one or more processors, controllers, ASICs, PLAs, PALs, CPLDs, FPGAs, logic devices, software programs, or other mechanisms that can be implemented to constitute a module. In an embodiment, the different modules described in this article can be implemented as discrete modules or the features and functions described can be shared in part or in whole between one or more modules. In other words, it is obvious to those skilled in the art who have read this specification that the various features and functions described in this article can be implemented in any given application and can be implemented in various combinations and arrangements in one or more separate or shared modules. Even if the elements of various features or functions may be described separately or requested as separate modules, those skilled in the art should understand that these features and functions can be shared in one or more common software and hardware elements, and that such description should not require or imply that separate hardware or software elements are used to implement these features or functions.

In one embodiment, where the components or modules of the present application are implemented in whole or in part using software, these software elements can be implemented to operate in conjunction with a computing or processing module that can perform the functions described herein. FIG13 shows an example computing module. Various embodiments are described in terms of this example computing module 1000. After reading this specification, it will become apparent to those skilled in the relevant art how to implement the present application using other computing modules or architectures.

13 , computing module 1000 may represent computing or processing capabilities such as found in a desktop computer, laptop computer, notebook computer, or tablet computer; a handheld computing device (tablet computer, PDA, smartphone, cell phone, palmtop, etc.); a mainframe, supercomputer, workstation, or server; or any other type of dedicated or general-purpose computing device that is desirable or suitable for a given application or environment. Computing module 1000 may also represent computing capabilities embedded within or otherwise available to a given device. For example, computing modules may be found in other electronic devices such as, for example, digital cameras, navigation systems, cell phones, portable computing devices, modems, routers, WAPs, terminals, and other electronic devices that may contain some form of processing capabilities.

The computing module 1000 may include, for example, one or more processors, controllers, control modules, or other processing devices, such as a processor 1004. The processor 1004 may be implemented using a general-purpose or dedicated processing engine, such as, for example, a microprocessor, controller, or other control logic. In the example shown, the processor 1004 is connected to a bus 1002, however, any communication medium may be used to facilitate interaction with other components of the computing module 1000 or for external communication.

The computing module 1000 may also include one or more memory modules, referred to herein simply as main memory 1008. For example, a preferred random access memory (RAM) or other dynamic storage may be used to store information and instructions to be executed by the processor 1004. The main memory 1008 may also be used to store temporary variables or other intermediate information during the execution of instructions to be executed by the processor 1004. The computing module 1000 may also similarly include a read-only memory ("ROM") or other static storage device coupled to the bus 1002 for storing static information and instructions for the processor 1004.

The computing module 1000 may also include one or more different forms of information storage mechanisms 1010, which may include, for example, a media drive 1012 and a storage unit interface 1020. The media drive 1012 may include a drive or other mechanism to support fixed or removable storage media 1014. For example, a hard drive, solid-state drive, tape drive, optical drive, CD, DVD, or Blu-ray disc drive (R or RW), or other removable or fixed media drive may be provided. Thus, the storage media 1014 may include, for example, a hard drive, solid-state drive, tape, cassette, optical disc, CD, DVD, Blu-ray disc, or other removable or fixed media that is read, written, or accessed by the media drive 1012. As these examples illustrate, the storage media 1014 may include computer-usable storage media having computer software or data stored therein.

In alternative embodiments, the information storage mechanism 1010 may include other similar means for allowing computer programs or other instructions or data to be loaded into the computing module 1000. These means may include, for example, fixed or removable storage units 1022 and interfaces 1020. Examples of such storage units 1022 and interfaces 1020 may include program cartridges and cartridge interfaces, removable memory (e.g., flash memory or other removable storage modules) and memory slots, PCMCIA slots and cards, and other fixed or removable storage units 1022 and interfaces 1020 that allow software and data to be transferred from the storage unit 1022 to the computing module 1000.

The computing module 1000 may also include a communication interface 1024. The communication interface 1024 can be used to allow software and data to be transmitted between the computing module 1000 and external devices. Examples of the communication interface 1024 may include a modem or software modem, a network interface (such as Ethernet, a network interface card, WiMedia, IEEE802.XX or other interface), a communication port (such as, for example, a USB port, an IR port, an RS232 port, an interface or other port) or other communication interface. The software and data transmitted via the communication interface 1024 may typically be transmitted on a signal, which may be an electronic signal, an electromagnetic signal (including an optical signal) or other signal that can be exchanged by a given communication interface 1024. These signals may be provided to the communication interface 1024 via a channel 1028. The channel 1028 can transmit signals and can be implemented using a wired or wireless communication medium. Some examples of channels may include a telephone line, a cellular link, an RF link, an optical link, a network interface, a local area network or a wide area network and other wired or wireless communication channels.

In this document, the terms "computer program medium" and "computer-usable medium" generally refer to temporary or non-temporary media, such as, for example, memory 1008, storage unit 1020, medium 1014, and channel 1028. These and other different forms of computer program media or computer-usable media may be involved in transmitting one or more sequences of one or more instructions to a processing device for execution. These instructions embedded in the medium are generally referred to as "computer program code" or "computer program product" (which may be grouped in the form of a computer program or other grouping). When executed, these instructions enable computing module 1000 to perform the features or functions of the present application discussed herein.

Although various exemplary embodiments and implementations have been described above, it should be understood that the various features, aspects, and functions described in one or more individual embodiments are not limited to the specific embodiments in which they are described, but may be applied alone or in various combinations to one or more other embodiments of the present application, whether or not such embodiments are described, and whether or not such features are presented as part of such described embodiments. Thus, the breadth and scope of the present application should not be limited by any of the exemplary embodiments described above.

The terms and phrases used in this document, and variations thereof, unless otherwise specifically stated, should be interpreted as open ended and not restrictive. As an example, the term "including" should be interpreted as meaning "including, but not limited to" or a similar meaning; the term "example" is used to provide an illustrative example of the term in question, not an exhaustive or limiting list; the term "one" should be interpreted as meaning "at least one," "one or more," or a similar meaning; adjectives such as "conventional," "traditional," "normal," "standard," "known," and terms of similar meaning should not be interpreted as limiting the terms described to a given time period or other available term at a given time, but should be read as including conventional, traditional, normal, and standard technology that may be available or known at any time now or in the future. Similarly, the technology referred to in this document is understood or known by a person of ordinary skill in the art, and these technologies include those technologies that are understood or known by a person of ordinary skill in the art now or at any time in the future.

The presence of expanded words and phrases, such as "one or more," "at least," "but not limited to," or other similar phrases in some examples, should not be construed as intending or requiring a narrower case in the absence of such expanded phrases. The use of the term "module" does not imply that the components or functionality described or claimed as part of a module are all configured in a common package. In fact, any or all of the various components in a module, whether control logic or other components, may be combined into a single package or stored separately and may further be distributed among multiple groups or packages or across multiple locations.

In addition, the various embodiments listed herein are described in the form of exemplary block diagrams, flow charts, and other diagrams. It will be apparent to those skilled in the art reading this document that these illustrative embodiments and their various alternatives can be implemented without being limited to the examples shown. For example, the block diagrams and their accompanying descriptions should not be construed as requiring a specific structure or configuration.

Although different embodiments of the present disclosure have been described above, it should be understood that they are disclosed by way of example only and not limitation. Similarly, the different figures describe exemplary structures or configurations of the present invention, which are used to assist in understanding the features and functions included in the present invention. The disclosure is not limited to the disclosed exemplary architectures or configurations, but rather the desired features can be implemented using various alternative architectures and configurations. In fact, it should be clear to those skilled in the art how to implement alternative functional, logical or physical partitioning and configurations to achieve the features required by the present invention. Similarly, multiple different component module names can be applied to different parts, which are different from those described here. In addition, with reference to the flow charts, operational descriptions and method claims, the order in which the steps are presented should not require that different embodiments perform the listed functions in the same order, unless the context indicates otherwise.

Although various exemplary embodiments and implementations of the present invention have been described above, it should be understood that the various features, aspects, and functions in one or more individual embodiments are not limited to the specific embodiments for which they are described, but may be applied alone or in various combinations to one or more other embodiments of the present disclosure, whether or not such embodiments have been described, and whether or not such features are presented as part of such embodiments. Thus, the breadth and scope of the present application should not be limited by any of the exemplary embodiments described above.

The terms and phrases used in this document and their variations, unless otherwise specifically stated, should be interpreted as open and not restrictive. As an example of the foregoing: the term "including" should be interpreted as meaning "including, but not limited to" or similar; the term "example" is used to provide an illustrative example of the use in the discussion, not an exhaustive or limiting list thereof; the term "one" should be understood as meaning "at least one", "one or more" or similar; adjectives such as "conventional", "traditional", "normal", "standard", "known" and terms of similar meaning should not be interpreted as limiting the terms described to a given time period or other available terms at a given time, but should be interpreted as including conventional, traditional, normal, standard technology that is available or known at any time now or in the future. Similarly, the technology mentioned in this document is understood or known by a person of ordinary skill in the art, and these technologies include those technologies that are understood or known by a person of ordinary skill in the art now or in the future.

The presence of expanded words and phrases, such as "one or more," "at least," "but not limited to," or other similar phrases in some examples, should not be construed as intending or requiring a narrower case in the absence of such expanded phrases. The use of the term "module" does not imply that the components or functionality described or claimed as part of a module are all configured in a common package. In fact, any or all of the various components in a module, whether control logic or other components, may be combined into a single package or stored separately and may further be distributed among multiple groups or packages or across multiple locations.

Furthermore, the various embodiments listed herein are described in the form of exemplary block diagrams, flow charts, and other diagrams. Those skilled in the art will appreciate that these illustrative embodiments and their various alternatives can be implemented without limitation to the examples shown. For example, the block diagrams and accompanying descriptions should not be construed as requiring a specific architecture or configuration.

Claims (49)

1. A method for generating a continuous dynamic range image, comprising: Receive the source image at a non-transitory computer-readable medium; and The continuous dynamic range image is generated by using one or more processors by defining the illuminance of each pixel of the source image as a continuous function based on the minimum dynamic range and the maximum dynamic range, wherein the continuous function includes a dynamic range continuum between the minimum dynamic range and the maximum dynamic range. 2. The method of claim 1, wherein generating the continuous dynamic range image further comprises: classifying the source image using the one or more processors for the minimum dynamic range and the maximum dynamic range. 3. The method of claim 2, wherein the source image is a video frame, and wherein the continuous dynamic range image is a continuous dynamic range video frame. 4. The method according to claim 1, wherein the continuous function is an illuminance path that represents the illuminance value of a pixel as a function of the peak illuminance of the display. 5. The method of claim 1, further comprising: displaying a graphical user interface on a display that allows the user to define or change the continuous function. 6. The method of claim 1, further comprising: compressing the continuous dynamic range image by using the one or more processors to approximate the continuous function using a truncated polynomial series. 7. The method of claim 3, further comprising: compressing the continuous dynamic range video frames by using the one or more processors to approximate the continuous function using a truncated polynomial series. 8. The method of claim 7, wherein the truncated polynomial series is a Chebyshev polynomial series. 9. The method of claim 7, further comprising: representing the polynomial coefficients of the truncated polynomial series in an image format. 10. The method of claim 9, further comprising: encoding the image format of the polynomial coefficients of the truncated polynomial series using a video codec. 11. The method of claim 1, wherein the maximum dynamic range corresponds to the maximum dynamic range of the display, each of the displays having an associated dynamic range, and wherein the minimum dynamic range corresponds to the minimum dynamic range of the display. 12. A system for generating continuous dynamic range images, comprising: One or more processors; and One or more non-transitory computer-readable media, operatively coupled to at least one of the one or more processors, and having instructions stored thereon, which, when executed by at least one of the one or more processors, cause the system to: Receive source image; and The continuous dynamic range image is generated by defining the illumination of each pixel of the source image as a continuous function based on the minimum dynamic range and the maximum dynamic range, wherein the continuous function includes a dynamic range continuum between the minimum dynamic range and the maximum dynamic range. 13. The system of claim 12, wherein the source image is a video frame, and wherein the continuous dynamic range image is a continuous dynamic range video frame. 14. The system of claim 13, wherein generating the continuous dynamic range video frames includes classifying the video frames for the minimum dynamic range and the maximum dynamic range. 15. The system of claim 12, wherein the continuous function is an illuminance path that represents the illuminance value of a pixel as a function of the peak illuminance of the display. 16. The system of claim 12, further comprising a display, and wherein when the instructions are executed by at least one of the one or more processors, the instructions further cause the system to: display a graphical user interface on the display that allows a user to define or change the successive functions. 17. The system of claim 13, wherein when the instructions are executed by at least one of the one or more processors, the instructions further cause the system to: compress the continuous dynamic range video frames by approximating the continuous function using a truncated polynomial series. 18. The system of claim 17, wherein the truncated polynomial series is a Chebyshev polynomial series. 19. A graphical user interface method for generating continuous dynamic range images or videos, comprising: Displayed on one or more monitors of a computer system: A graded version of an image, wherein each of the graded versions of the image is graded for a different dynamic range display; and A control for changing a continuity function that defines the illuminance of a first set of pixels of an image based on a minimum dynamic range and a maximum dynamic range, wherein the continuity function includes a dynamic range continuum between the minimum dynamic range and the maximum dynamic range; The computer system receives user input that actuates the control to change the continuous function; and In response to receiving user input that actuates the control to change the successive function, a modified version of each of the graded versions of the image is displayed on one or more displays. 20. The graphical user interface method of claim 19, wherein the image is a first video frame corresponding to a video. 21. The graphical user interface method of claim 19, further comprising: The computer system receives user input selecting a second video frame, the second video frame corresponding to the video; and In response to receiving the user input selecting a second video frame, the one or more displays are prompted to display graded versions of the second video frame, each of which is graded for a different dynamic range display. 22. The graphical user interface method of claim 19, wherein the continuous function is an illuminance path that represents the illuminance value of a pixel as a function of the peak illuminance of at least one of the one or more displays. 23. The graphical user interface method of claim 19, further comprising displaying a first user-selectable mask, wherein the continuous function defining the illumination of the first set of pixels of the image is associated with the first user-selectable mask. 24. The graphical user interface method of claim 22, further comprising: receiving user input at the computer system to select a second mask, the second mask being associated with a second continuous function defining the illuminance of a second set of pixels of the image based on the minimum dynamic range and the maximum dynamic range. 25. The graphical user interface method of claim 19, further comprising: receiving user input at the computer system selecting a maximum rating version of the image and selecting a minimum rating version of the image. 26. A graphical user interface system for generating continuous dynamic range images or videos, comprising: monitor; One or more processors; and One or more non-transitory computer-readable media, operatively coupled to at least one of the one or more processors, and having instructions stored thereon that, when executed by at least one of the one or more processors, cause the graphical user interface system to: Displaying a graphical user interface on the display includes: A graded version of the image, wherein each of the graded versions is graded for different dynamic range displays; and A control for changing a continuity function that defines the illuminance of a first set of pixels of an image based on a minimum dynamic range and a maximum dynamic range, wherein the continuity function includes a dynamic range continuum between the minimum dynamic range and the maximum dynamic range; Receive data corresponding to user input that actuates the control to change the continuous function; and In response to receiving the data corresponding to the user input that actuates the control to change the successive function, a modified version of each of the graded versions of the image is displayed on the display. 27. The graphical user interface system of claim 26, wherein the continuous function is an illuminance path that represents the illuminance value of a pixel as a function of the peak illuminance of the display. 28. The graphical user interface system of claim 26, wherein when the instructions are executed by at least one of the one or more processors, the instructions further cause the graphical user interface system to: display a first user-selectable mask on the display, wherein the continuous function defining the illuminance of the first set of pixels of the image is associated with the first user-selectable mask. 29. The graphical user interface system of claim 28, wherein when the instructions are executed by at least one of the one or more processors, the instructions further cause the graphical user interface system to: receive data corresponding to user input for selecting a second mask, the second mask being associated with a second continuous function defining the illuminance of a second set of pixels of the image based on the minimum dynamic range and the maximum dynamic range. 30. The graphical user interface system of claim 26, wherein when the instructions are executed by at least one of the one or more processors, the instructions further cause the graphical user interface system to: receive data corresponding to selecting the maximum grade version of the image and selecting the minimum grade version of the image. 31. The graphical user interface system of claim 26, wherein the image is a first video frame corresponding to a video, and wherein when the instruction is executed by at least one of the one or more processors, the instruction further causes the graphical user interface system to: Receive data corresponding to user input for selecting a second video frame, the second video frame corresponding to the video; and In response to receiving the data corresponding to the user input for selecting the second video frame, a graded version of the second video frame is displayed on the display, wherein each of the graded versions is graded for a different dynamic range display. 32. A method for compressing and encoding a continuous dynamic range video comprising video frames, comprising: take over: Minimum dynamic range grading image of video frames; The maximum dynamic range graded image of the video frame; and Metadata including the continuous dynamic range function of each pixel of the video frame, wherein the continuous dynamic range function includes a dynamic range continuum between the minimum dynamic range and the maximum dynamic range; The continuous dynamic range function is represented by a vector of coefficients of a truncated polynomial series that approximates the continuous dynamic range function, in order to compress the continuous dynamic range video; A vector representing the coefficients of the truncated polynomial series in image format; and The image format is encoded using a video codec to encode the vector of coefficients of the truncated polynomial series. 33. The method of claim 32, wherein the truncated polynomial series is a Chebyshev polynomial series. 34. The method of claim 32, further comprising: encoding the minimum dynamic range grading image and the maximum dynamic range grading image jointly and non-independently based on redundancy between the minimum dynamic range grading image and the maximum dynamic range grading image. 35. A method for allocating a continuous dynamic range video comprising video frames, the method comprising allocating the following to each of a plurality of receivers having an associated display: The minimum dynamic range level of each of the video frames; The maximum dynamic range level of each of the video frames; and Metadata that defines the illumination of each pixel in each of the video frames as an approximation of a continuous function between the minimum and maximum dynamic range, wherein the continuous function is approximated using a polynomial series. 36. The method of claim 35, wherein the continuous dynamic range video is transmitted to the plurality of receivers as an over-the-air broadcast television signal, satellite television network signal, or cable television network signal. 37. The method of claim 35, wherein the continuous dynamic range video is transmitted from a content server to the plurality of receivers via a computer network. 38. The method of claim 35, wherein the continuous function is an illuminance path that represents the illuminance value of a pixel as a function of the peak illuminance of the display. 39. The method of claim 35, wherein the minimum dynamic range level and the maximum dynamic range level are co-encoded. 40. A method for decoding a continuous dynamic range image for display on a display having an associated dynamic range, comprising: Received encoded continuous dynamic range image, including: The minimum dynamic range grading version of the image; The maximum dynamic range graded version of the image; and Corresponding to the continuous dynamic range metadata of the image, the continuous dynamic range metadata defines the illuminance of the image's pixels as the coefficients of a truncated polynomial series, which approximately defines a continuous function of the illuminance of the pixels between the minimum and maximum dynamic range. Decoding the encoded continuous motion image using a codec; and A dynamic range representation of the image is generated based on the decoded continuous dynamic range image and the associated dynamic range of the display. 41. The method of claim 40, wherein the image corresponds to a video frame, and wherein the encoded continuous dynamic range image is a video-coded continuous dynamic range video frame. 42. The method of claim 40, wherein the minimum dynamic range grading version of the image and the maximum dynamic range grading version of the image are co-encoded based on a scalable video coding codec, and wherein decoding the consecutive dynamic range video frames comprises decoding the co-encoded minimum dynamic range grading version of the image and the maximum dynamic range grading version of the image using the scalable video coding codec. 43. The method of claim 40, wherein the truncated polynomial series is a Chebyshev series. 44. The method of claim 40, wherein the continuous function is an illuminance path. 45. A system for decoding a continuous dynamic range image for display on a display having an associated dynamic range, comprising: The display has the associated dynamic range; One or more processors; and One or more non-transitory computer-readable media, operatively coupled to at least one of the one or more processors, and having instructions stored thereon, which, when executed by the at least one of the one or more processors, cause a receiver to: Received encoded continuous dynamic range image, including: The minimum dynamic range grading version of the image; The maximum dynamic range graded version of the image; and Corresponding to the continuous dynamic range metadata of the image, the continuous dynamic range metadata defines the illuminance of the image's pixels as the coefficients of a truncated polynomial series, which approximately defines a continuous function of the illuminance of the pixels between the minimum and maximum dynamic range. Decode the encoded continuous dynamic range image; A dynamic range representation of the image is generated based on the associated dynamic range of the display; and The dynamic range representation of the image is displayed on the display. 46. The system of claim 45, wherein the image corresponds to a video frame, and wherein the encoded continuous dynamic range image is a video-coded continuous dynamic range video frame. 47. The system of claim 45, wherein the minimum dynamic range graded version of the image and the maximum dynamic range graded version of the image are co-encoded and non-independently using a codec, and wherein decoding the continuous dynamic range video frame includes decoding the minimum dynamic range graded version of the image and the maximum dynamic range graded version of the image that have been co-encoded and non-independently using the codec. 48. The system of claim 45, wherein the truncated polynomial series is a Chebyshev series. 49. The system of claim 45, wherein the continuous function is an illuminance path.