Koninklijke Philips Corporation N.v.

Entropic Communications, Inc.

Trident Microsystems (far East) Ltd.

Tp Vision Holding B.v.

Mark Jozef Willem Mertens

Gerard De Haan

Chris Damkat

Johannes Gerardus Rijk Van Mourik

Martin Hammer

Philip Steven Newton

Rutger Nijland

Remco Muijs

Renatus Josephus Van Der Vleuten

Johannes Yzebrand Tichelaar

Jeroen Hubert Christoffel Jacobus Stessen

Roeland Focco Everhard Goris

Wilhelmus Hendrikus Alfonsus Bruls

Remco Theodorus Johannes Muijs

Patrick Luc Els Vandewalle

Cornelis Wilhelmus Kwisthout

Ronaldus Maria Aarts

Christiaan Varekamp

Wiebe De Haan

Stein Kuiper

Frederik Jan De Bruijn

Bokke Johannes Feenstra

Michiel Adriaanszoon Klompenhouwer

Erno Hermanus Antonius Langendijk

Gerben Johan Hekstra

Bart Gerard Bernard Barenbrug

Edwin Maria Wolterink

Leo Jan Velthoven

Oleg Belik

Gerjan Franciscus Arthur Van De Walle

Patrick Luc E Vandewalle

Stephan Mietens

Cris Damkat

To allow better quality rendering of video on any display, a method is proposed of encoding, in addition to video data (VID), additional data (DD) comprising at least one change time instant (TMA_) indicating a change in time of a characteristic luminance (CHRLUM) of the video data, which characteristic luminance summarizes the set of luminances of pixels in an image of the video data, the method comprising:

Apparatuses and methods for improved encoding of images for better handling by displays

A method is proposed of encoding a change time The change time indicates a change in time of a characteristic luminance of the video data. The characteristic luminance summarizes the set of luminances of pixels the video data. The encoding of the time variation of the characteristic luminance provides a more compact and accurate storage and transmission of content.

Methods and apparatuses to encode both high dynamic range images and low dynamic range images. The input video may also convert the high dynamic range image to an image of lower luminance dynamic range by applying either a scaling the high dynamic range image to a predetermined scale of the luma axis or by applying a sensitivity tone mapping which changes the brightnesses of pixel colors falling within a subrange or by applying a gamma function or by applying an arbitrary monotonically increasing function mapping the lumas.

Methods and apparatuses for encoding an HDR images, and methods and apparatuses for use of such encoded images

To enable a high quality HDR video communication, which can work by sending corresponding LDR images potentially via established LDR video communication technologies, which works well in practical situations, applicant has invented a HDR video decoder () arranged to calculate a HDR image (Im_RHDR) based on applying to a received 100 nit standard dynamic range image (Im_RLDR) a set of luminance transformation functions, the functions comprising at least a coarse luminance mapping (FC), which is applied by a dynamic range optimizer (), and a mapping of the darkest value (0) of an intermediate luma (Y′HPS), being output of the dynamic range optimizer, to a received black offset value (Bk_off) by a range stretcher (), the video decoder comprising a gain limiter () arranged to apply an alternate luminance transformation function to calculate a subset () of the darkest luminances of the HDR image, from corresponding darkest lumas (Y′_in) of the standard dynamic range image.

Encoding and decoding HDR videos

A method and apparatus analyze a difference of at least two gradings of an image on the basis of: obtaining a first graded picture (LDR) with a first luminance dynamic range; obtaining data encoding a grading of a second graded picture (HDR) with a second luminance dynamic range, different from the first luminance dynamic range; and determining a grading difference data structure (DATGRAD) on the basis of at least the data encoding the grading of the second graded picture (HDR), which allows more intelligently adaptive encoding of the imaged scenes, and consequently also better use of those pictures, such as higher quality rendering under various rendering scenarios.

Apparatus and methods for analyzing image gradings

To enable a high quality HDR video communication, which can work by sending corresponding LDR images potentially via established LDR video communication technologies, which works well in practical situations, applicant has invented a HDR video decoder () arranged to calculate a HDR image (Im_RHDR) based on applying to a received 100 nit standard dynamic range image (Im_RLDR) a set of luminance transformation functions, the functions comprising at least a coarse luminance mapping (FC), which is applied by a dynamic range optimizer (), and a mapping of the darkest value (0) of an intermediate luma (Y'HPS), being output of the dynamic range optimizer, to a received black offset value (Bk_off) by a range stretcher (), the video decoder comprising a gain limiter () arranged to apply an alternate luminance transformation function to calculate a subset () of the darkest luminances of the HDR image, from corresponding darkest lumas (Y&#x2032;_in) of the standard dynamic range image.

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:

To enable better color and in particular color saturation control for HDR image handling systems which need to do luminance dynamic range conversion, e.g. from a SDR image to an image optimized for rendering on a display of higher display peak brightness and dynamic range, the inventors invented an apparatus () for processing a color saturation (C'bL, C&#x2032;rL) of an input color (Y&#x2032;L, C&#x2032;bL, C&#x2032;rL) of an input image (Im_RLDR) to yield an output color (Y&#x2032;M, Cb&#x2032;M, Cr&#x2032;M) of an output image (Im3000nit) corresponding to the input image, which output image is a re-grading of the input image characterized by the fact that its pixel colors have a different normalized luminance position (Y2) compared to the normalized luminance positions of the input colors (Y1), the normalized luminances being defined as the luminance of a pixel divided by the respective maximal codeable luminance of the image's luminance representation, whereby the ratio of the maximum codeable luminance of the input image and the maximum codeable luminance of the output image is at least 4 or larger, or &#xbc;or smaller, the apparatus comprising:

Optimized decoded high dynamic range image saturation

This invention provides a process which allows better quality rendering of video on any display. The process proposes encoding, video data and additional data. The additional data includes a change time instant. The change time instant can be used to indicate a change in time of a characteristic luminance. The characteristic luminance summarizes the set of luminances of pixels in an image of the video data. The process includes generating on descriptive data based on the video data and encoding and outputting the descriptive data as additional data.

To enable practical and quick generation of a family of good looking HDR gradings for various displays on which the HDR image may need to be shown, we describe color transformation apparatus () to calculate resultant colors (R, G, B) of pixels of an output image (IM_MDR) for a display with a display peak brightness (PB_D) starting from input colors (R,G,B) of pixels of an input image (Im_in) having a maximum luma code corresponding to a first image peak brightness (PB_IM) which is different from the display peak brightness, characterized in that the color transformation apparatus comprises:

Optimizing high dynamic range images for particular displays

The method of analyzing a difference of at least two gradings of an image on the basis of: obtaining a first graded picture (LDR) with a first luminance dynamic range; obtaining data encoding a grading of a second graded picture (HDR) with a second luminance dynamic range, different from the first luminance dynamic range; determining a grading difference data structure (DATGRAD) on the basis of at least the data encoding the grading of the second graded picture (HDR), allows more intelligently adaptive encoding of the imaged scenes, and consequently also better use of those pictures, such as higher quality rendering under various rendering scenarios.

Apparatuses and methods for analyzing image gradings

To enable better color and in particular color saturation control for HDR image handling systems which need to do luminance dynamic range conversion, e.g. from a SDR image to an image optimized for rendering on a display of higher display peak brightness and dynamic range, the inventors invented an apparatus () for processing a color saturation (C'bL, C&#x2032;rL) of an input color (Y&#x2032;L, C&#x2032;bL, C&#x2032;rL) of an input image (Im RLDR) to yield an output color (Y&#x2032;M, Cb&#x2032;M, Cr&#x2032;M) of an output image (Im3000nit) corresponding to the input image, which output image is a re-grading of the input image characterized by the fact that its pixel colors have a different normalized luminance position (Y2) compared to the normalized luminance positions of the input colors (Y1), the normalized luminances being defined as the luminance of a pixel divided by the respective maximal codeable luminance of the image's luminance representation, whereby the ratio of the maximum codeable luminance of the input image and the maximum codeable luminance of the output image is at least 4 or larger, or &#xbc;or smaller, the apparatus comprising a luminance processor () arranged to apply a display tuned luminance mapping function (F_L_da) to determine an output luminance (Y&#x2032;M) from the input luminance (Y&#x2032;L) of the input color, the apparatus further comprising a saturation factor determination unit () arranged to calculate a final saturation processing strategy (b; Bcorr) based on an initial saturation processing strategy (F_sat) and based on a secondary luminance value (Y&#x2032;_H) which is derivable from the output luminance (Y&#x2032;M) by applying a luminance mapping function (F M2H) which is based on the luminance mapping function (F_L_s2h).

Growing community of inventors

Eindhoven, Netherlands

Mark Jozef Willem Mertens