Disclosed herein are system, apparatus, article of manufacture, method and/or computer program product embodiments, and/or combinations and sub-combinations thereof, for dynamic tone mapping of video content. An example embodiment operates by identifying, by a dynamic tone mapping system executing on a media device, characteristics of a first video signal having a first dynamic range based on a frame-by-frame analysis of the first video signal. The example embodiment further operates by modifying, by the dynamic tone mapping system, a tone mapping curve based on the characteristics of the first video signal to generate a modified tone mapping curve. Subsequently, the example embodiment operates by converting, by the dynamic tone mapping system, the first video signal based on the modified tone mapping curve to generate a second video signal having a second dynamic range that is less than the first dynamic range.

Disclosed herein are system, apparatus, article of manufacture, method and/or computer program product embodiments, and/or combinations and sub-combinations thereof, for dynamic tone mapping of video content. An example embodiment operates by identifying, by a dynamic tone mapping system executing on a media device, characteristics of a first video signal having a first dynamic range based on a frame-by-frame analysis of the first video signal. The example embodiment further operates by modifying, by the dynamic tone mapping system, a tone mapping curve based on the characteristics of the first video signal to generate a modified tone mapping curve. Subsequently, the example embodiment operates by converting, by the dynamic tone mapping system, the first video signal based on the modified tone mapping curve to generate a second video signal having a second dynamic range that is less than the first dynamic range.

A computer-implemented method includes accessing a high dynamic range (HDR) media content item. Statistical analysis is performed to determine statistical information associated with the HDR media content item at each incremental portion of the HDR media content item. Metadata for each incremental portion of the HDR media content item is generated. A standard dynamic range (SDR) version of the content is derived using the HDR metadata. The metadata and an SDR version of the HDR media content item is transmitted to a storage service. The metadata and the SDR version are caused to be received at a display device. The SDR version is converted to HDR with a dynamic range bounded based on the metadata.

An image processing apparatus comprises a first acquisition unit configured to acquire, based on a luminance distribution in an input image, first control information for controlling characteristics of luminance gradation correction to be applied on the input image, a second acquisition unit configured to acquire, based on the first control information, second control information for controlling characteristics of luminance gradation correction to be applied on the input image, and a correction unit configured to correct luminance gradation of the input image based on the second control information.

A display system includes a conversion apparatus converting video luminance including a luminance value in a first luminance range and a display apparatus connected thereto and displaying the video. The conversion apparatus includes a first acquisition unit, a first luminance converter, a second luminance converter, a quantization converter, and an output unit outputting a third luminance signal to the display apparatus. The display apparatus includes: a second acquisition unit acquiring the third luminance signal and setting information indicating display settings recommended to the display apparatus in display of the video; a display setting unit setting the display apparatus, using the setting information; a third luminance converter converting a third code value indicated by the third luminance signal into a second luminance value compatible with a second luminance range, using the setting information; and a display controller displaying the video on the display apparatus based on the second luminance value.

A display system includes a conversion apparatus converting video luminance including a luminance value in a first luminance range and a display apparatus connected thereto and displaying the video. The conversion apparatus includes a first acquisition unit, a first luminance converter, a second luminance converter, a quantization converter, and an output unit outputting a third luminance signal to the display apparatus. The display apparatus includes: a second acquisition unit acquiring the third luminance signal and setting information indicating display settings recommended to the display apparatus in display of the video; a display setting unit setting the display apparatus, using the setting information; a third luminance converter converting a third code value indicated by the third luminance signal into a second luminance value compatible with a second luminance range, using the setting information; and a display controller displaying the video on the display apparatus based on the second luminance value.

An image processor receives an input image with enhanced dynamic range to be displayed on a target display which has a different dynamic range than a reference display. After optional color transformation (110) and perceptual quantization (115) of the input image, a multiscale mapping process (120) combines linear (125) and non-linear (130) mapping functions to its input to generate first (127) and second (132) output images, wherein the first and second output images may have a different dynamic range than the first image. A frequency transform (135, 140), such as the FFT, is applied to the first and second output images to generate first (137) and second (142) transformed images. An interpolation function (145) is applied to the first and second transformed images to generate an interpolated transformed image (147). An inverse transform function (150) is applied to the interpolated transformed image to generate an output tone-mapped image (152). The output tone-mapped image is post-processed to be displayed on the target display.

An image processor receives an input image with enhanced dynamic range to be displayed on a target display which has a different dynamic range than a reference display. After optional color transformation (110) and perceptual quantization (115) of the input image, a multiscale mapping process (120) combines linear (125) and non-linear (130) mapping functions to its input to generate first (127) and second (132) output images, wherein the first and second output images may have a different dynamic range than the first image. A frequency transform (135, 140), such as the FFT, is applied to the first and second output images to generate first (137) and second (142) transformed images. An interpolation function (145) is applied to the first and second transformed images to generate an interpolated transformed image (147). An inverse transform function (150) is applied to the interpolated transformed image to generate an output tone-mapped image (152). The output tone-mapped image is post-processed to be displayed on the target display.

For obtaining good quality luminance dynamic range conversion, we describe an image color processing apparatus (200) arranged to transform an input color (R,G,B) of a pixel of an input image (Im_R2) having a first luminance dynamic range into an output color (Rs, Gs, Bs) of a pixel of an output image (Im_res) having a second luminance dynamic range, which first and second dynamic ranges differ in extent by at least a multiplicative factor 1.5, comprising: a maximum calculation unit (201) arranged to calculate the maximum (M) of at least three components of the input color; a brightness mapper (202) arranged to apply a function (F) to the maximum, yielding an output value (F(M)), whereby the function is predetermined having a constraint that the output value for the highest value of the maximum (M) cannot be higher than 1.0; a scaling parameter calculator (203) arranged to calculate a scaling parameter (a) being equal to the output value F(M)) divided by the maximum (M); and a multiplier (204) arranged to multiply the three color components of the input color (R,G,B) by the scaling parameter (a), yielding the color components of the output color, wherein the color processing apparatus (200) comprises at least one component multiplier (303) arranged to multiply a component (B) of the input color with a weight (wB) being a real number yielding a scaled component (Bw) prior to input of that component in the maximum calculation unit (201).

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).