To preserve backward compatibility with a non-HDR device or service, an HDR picture may be represented using a modulation value and an SDR picture representative of the HDR picture. The modulation value and the SDR picture can then be encoded into the bitstream. At the receiving side, the modulation value and the SDR picture can be decoded. Based on the modulation value, the SDR picture can be mapped to a decoded HDR picture. For a non-HDR device or service, the modulation value information may be discarded and only the SDR picture is decoded. In particular, the modulation value may be implicitly signaled, using quad-tree representation information, intra coding information, inter partition mode information or motion vector residual information.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for remapping for mixed dynamic range content. In one aspect, a method for remapping for mixed dynamic range content, the method includes obtaining an image to be displayed that includes both first dynamic range content and second dynamic range content, determining that the image includes first dynamic range content at a first pixel, determining a first remapped value for the first pixel based on a lookup table for first dynamic range content and an initial value for the first pixel, providing the first remapped value for the first pixel for display, determining that the image includes second dynamic range content at a second pixel, determining a second remapped value for the second pixel based on a second initial value for the second pixel, and providing the second remapped value for the second pixel for display.

To enable a good HDR image or video coding technology, being able to yield high dynamic range images as well as low dynamic range images, we invented a method of encoding a high dynamic range image (M_HDR), comprising the steps of:

converting the high dynamic range image to an image of lower luminance dynamic range (LDR_o) by applying a) scaling the high dynamic range image to a predetermined scale of the luma axis such as [0,1], b) applying a sensitivity tone mapping which changes the brightnesses of pixel colors falling within at least a subrange comprising the darker colors in the high dynamic range image, c) applying a gamma function, and d) applying an arbitrary monotonically increasing function mapping the lumas resulting from performing the steps b and c to output lumas of the lower dynamic range image (LDR_o); and

outputting in an image signal (S_im) a codification of the pixel colors of the lower luminance dynamic range image (LDR_o), and

outputting in the image signal (S_im) values encoding the functional behavior of the above color conversions as metadata, or values for the inverse functions, which metadata allows to reconstruct a high dynamic range image (Rec_HDR) from the lower luminance dynamic range image (LDR_o).

To enable a good HDR image or video coding technology, being able to yield high dynamic range images as well as low dynamic range images, we invented a method of encoding a high dynamic range image (M_HDR), comprising the steps of:

converting the high dynamic range image to an image of lower luminance dynamic range (LDR_o) by applying a) scaling the high dynamic range image to a predetermined scale of the luma axis such as [0,1], b) applying a sensitivity tone mapping which changes the brightnesses of pixel colors falling within at least a subrange comprising the darker colors in the high dynamic range image, c) applying a gamma function, and d) applying an arbitrary monotonically increasing function mapping the lumas resulting from performing the steps b and c to output lumas of the lower dynamic range image (LDR_o); and

outputting in an image signal (S_im) a codification of the pixel colors of the lower luminance dynamic range image (LDR_o), and

outputting in the image signal (S_im) values encoding the functional behavior of the above color conversions as metadata, or values for the inverse functions, which metadata allows to reconstruct a high dynamic range image (Rec_HDR) from the lower luminance dynamic range image (LDR_o).

There is provided a method for encoding and decoding a signal. The method comprises receiving a first signal (900) and a second signal (960), the first and second signals comprising different versions of a common content, the first signal (900) using a first signal element coding format and the second signal (960) using a second signal element coding format. The first signal (900) is encoded by a lower encoding module (1103) to generate a lower encoded signal (910). The lower encoded signal (910) is decoded to generate a lower decoded signal. The lower decoded signal is processed by at least converting from the first signal element coding format to the second signal element coding format and up-sampling, to produce a processed signal. The processed signal and the second signal (960) are processed by an upper encoding module (1107) to generate an upper encoded signal (920).

There is provided a method for encoding and decoding a signal. The method comprises receiving a first signal (900) and a second signal (960), the first and second signals comprising different versions of a common content, the first signal (900) using a first signal element coding format and the second signal (960) using a second signal element coding format. The first signal (900) is encoded by a lower encoding module (1103) to generate a lower encoded signal (910). The lower encoded signal (910) is decoded to generate a lower decoded signal. The lower decoded signal is processed by at least converting from the first signal element coding format to the second signal element coding format and up-sampling, to produce a processed signal. The processed signal and the second signal (960) are processed by an upper encoding module (1107) to generate an upper encoded signal (920).

Network services encode multimedia content, such as video, into multiple adaptive bitrate streams of encoded video and a separate trick play stream of encoded video to support trick play features. The trick play stream is encoded at a lower encoding bitrate and frame rate than each of the adaptive bitrate streams. The adaptive bitrate streams and the trick play stream are stored in the network services. During normal content streaming and playback, a client device downloads a selected one of the adaptive bitrate streams from network serviced for playback at the client device. To implement a trick play feature, the client device downloads the trick play stream from the network services for trick play playback.

Network services encode multimedia content, such as video, into multiple adaptive bitrate streams of encoded video and a separate trick play stream of encoded video to support trick play features. The trick play stream is encoded at a lower encoding bitrate and frame rate than each of the adaptive bitrate streams. The adaptive bitrate streams and the trick play stream are stored in the network services. During normal content streaming and playback, a client device downloads a selected one of the adaptive bitrate streams from network serviced for playback at the client device. To implement a trick play feature, the client device downloads the trick play stream from the network services for trick play playback.

Different implementations are described, particularly implementations for processing a medium dynamic range video signal are presented. In a method for processing such a video signal a medium dynamic range video signal and associated metadata are received, wherein the metadata include data representative of a peak luminance value of the medium dynamic range video signal. In addition, data representative of a peak luminance value of a presentation display are received. It is determined whether the peak luminance value of the medium dynamic range video signal is greater or lower than the peak luminance value of the presentation display. A processor is configured based on the determination, wherein the processor has a first mode to reconstruct a high dynamic range video signal based on a received standard dynamic range video signal and associated metadata, and a second mode to optimize a received high dynamic range video signal for the rendering device. The medium dynamic range video signal is processed by the processor in the first mode if the peak luminance value of the medium dynamic range video signal is smaller than the peak luminance value of the presentation display and in the second mode if the peak luminance value of the medium dynamic range video signal is greater than the peak luminance value of the presentation display.

Different implementations are described, particularly implementations for processing a medium dynamic range video signal are presented. In a method for processing such a video signal a medium dynamic range video signal and associated metadata are received, wherein the metadata include data representative of a peak luminance value of the medium dynamic range video signal. In addition, data representative of a peak luminance value of a presentation display are received. It is determined whether the peak luminance value of the medium dynamic range video signal is greater or lower than the peak luminance value of the presentation display. A processor is configured based on the determination, wherein the processor has a first mode to reconstruct a high dynamic range video signal based on a received standard dynamic range video signal and associated metadata, and a second mode to optimize a received high dynamic range video signal for the rendering device. The medium dynamic range video signal is processed by the processor in the first mode if the peak luminance value of the medium dynamic range video signal is smaller than the peak luminance value of the presentation display and in the second mode if the peak luminance value of the medium dynamic range video signal is greater than the peak luminance value of the presentation display.