公开(公告)号：WO2022233587A1

公开(公告)日：2022-11-10

申请号：PCT/EP2022/060575

申请日：2022-04-21

Applicant: KONINKLIJKE PHILIPS N.V.

Inventor： VAN DER VLEUTEN, Renatus, Josephus

IPC: G06T5/00

Abstract: To enable a good quality optimization of the luminances of an image, so that they are not only optimized for a particular maximum displayable luminance of a display, but also a particular amount of light in the viewing environment in which the display is watched, the inventor has invented a method of processing an input image to obtain an output image, wherein the input image has pixels which have input luminances which fall within a first luminance dynamic range (DR_1), which first luminance dynamic range has a first maximum luminance (PL_V_HDR),wherein a reference luminance mapping function (F_L) is received as metadata associated with the input image,wherein the reference luminance mapping function specifies a relationship between luminances of a first reference image and luminances of a second reference image,wherein the first reference image has a first reference maximum luminance and the second reference image has a second reference maximum luminance,wherein the input image is equal to one of the first reference image and the second reference image,wherein the output image is not equal to the first reference image nor the second reference image;wherein the processing comprises applying an adapted luminance mapping function (FL_DA) to the input pixel luminances, to obtain the output luminances,wherein the adapted luminance mapping function (FL_DA) is calculated based on the reference luminance mapping function (F_L) and a maximum luminance value (PLA), wherein the calculation involves finding a position on a metric which corresponds to the maximum luminance value (PLA),wherein a first endpoint of the metric corresponds to the first maximum luminance (PL_V_HDR) and a second endpoint of the metric corresponds to a maximum luminance of one of the first reference image and the second reference image not being equal to the input image,characterized in that maximum luminance value (PLA) is calculated based on a maximum luminance (PL_D) of a display which is to be supplied with the output image, and a black level value (b) of the display,wherein the calculation comprises applying an inverse of an electro-optical transfer function to the maximum luminance (PL_D), subtracting from the resulting value the black level value (b), and applying the electro-optical transfer function to the subtraction to obtain the maximum luminance value (PLA).

公开(公告)号：WO2017129793A1

公开(公告)日：2017-08-03

申请号：PCT/EP2017/051852

申请日：2017-01-27

Applicant: KONINKLIJKE PHILIPS N.V.

Inventor： VAN DER VLEUTEN, Renatus, Josephus

IPC: H04N19/117 ,  H04N19/80 ,  H04N19/85 ,  H04N19/86 ,  H04N19/59 ,  H04N5/20 ,  H04N9/67

CPC classification number: H04N19/117 ,  G09G2340/0428 ,  H04N5/20 ,  H04N9/67 ,  H04N9/68 ,  H04N19/59 ,  H04N19/80 ,  H04N19/85 ,  H04N19/86

Abstract: A video encoder and decoder system includes a video decoder (220) converting in input HDR images in a luma and chrominance representation to SDR images in a luma and subsampled chrominance representation by directly applying dynamic range conversion gains in the luma and subsampled chrominance domain. An video encoder may perform the opposite operation and convert from SDR to HDR by directly applying dynamic range conversion gains in the luma and subsampled chrominance domain.

Abstract translation: 视频编码器和解码器系统包括视频解码器（220），其通过直接将动态范围转换增益应用于亮度和色度表示中，将亮度和色度表示中的输入HDR图像转换为亮度和二次取样色度表示中的SDR图像 亮度和二次采样色度域。 视频编码器可以执行相反的操作并通过在亮度和二次采样色度域中直接应用动态范围转换增益从SDR转换为HDR。

公开(公告)号：WO2020048790A1

公开(公告)日：2020-03-12

申请号：PCT/EP2019/072536

申请日：2019-08-22

Applicant: KONINKLIJKE PHILIPS N.V.

Inventor： VAN DER VLEUTEN, Renatus, Josephus ,  NIJLAND, Rutger ,  TICHELAAR, Johannes, Yzebrand

IPC: H04N19/98 ,  G06T5/00 ,  H04N19/162 ,  H04N19/179

Abstract: At least some applications in the total HDR video chain desire some more sophisticated approach, such as a high dynamic range video encoder (900), arranged to receive via an image input (920) an input high dynamic range image (MsterHDR) which has a first maximum pixel luminance (PB_C_H50), the encoder being arranged to receive via a metadata input (921) a master luma mapping function (FL_50t1), which luma mapping function defines the relationship between normalized lumas of the input high dynamic range image and normalized lumas of a corresponding standard dynamic range image (Im_LDR) having a maximum pixel luminance of preferably 100 nit, characterized in that the encoder further comprises a metadata input (923) to receive a second maximum pixel luminance (PB_CH), and the encoder further being characterized in that it comprises: - a HDR function generation unit (901) arranged to apply a standardized algorithm to transform the master luma mapping function (FL_50t1) into a adapted luma mapping function (F_H2hCI), which relates normalized lumas of the input high dynamic range image to normalized luminances of an intermediate dynamic range image (IDR) which is characterized by having a maximum possible luminance being equal to the second maximum pixel luminance (PB_CH); an IDR image calculation unit (902) arranged to apply the adapted luma mapping function (F_H2hCI) to lumas of pixels of the input high dynamic range image (MsterHDR) to obtain lumas of pixels of the intermediate dynamic range image (IDR); and an IDR mapping function generator (903) arranged to derive on the basis of the master luma mapping function (FL_50t1) and the adapted luma mapping function (F_H2hCI) a channel luma mapping function (F_I2sCI), which defines as output the respective normalized lumas of the standard dynamic range image (Im_LDR) when given as input the respective normalized lumas of the intermediate dynamic range image (IDR); the encoder being further characterized to have as output: the intermediate dynamic range image (IDR), as first metadata the second maximum pixel luminance (PB_CH), as second metadata the channel luma mapping function (F_I2sCI); and as third metadata the first maximum pixel luminance (PB_C_H50).

公开(公告)号：WO2019170465A1

公开(公告)日：2019-09-12

申请号：PCT/EP2019/054645

申请日：2019-02-26

Applicant: KONINKLIJKE PHILIPS N.V.

Inventor： VAN DER VLEUTEN, Renatus, Josephus

IPC: H04N1/00 ,  H04N1/56 ,  G09G5/02 ,  H04N1/407 ,  H04N1/60

Abstract: To be able to correctly color process YCbCr colors wherein the luma Y has a double functional definition which changes above a certain luma value from one functional shape to another (like HLG) the inventor invented an image color transformer (208) comprising a luminance mapping unit (302) and a chrominance mapping unit (321), arranged to get as input an YCbCr-defmed pixel color of an input image (Im_RLDR) in which the luma component (Y) is defined by an opto-electrical transfer function which allocates lumas for a lower part of a range of pixel luminances (DR_h) according to a square root function, and lumas for an upper part of the pixel luminances according to a logarithmic function, and arranged to calculate an output color (RH,GH,BH) of an output image (Im3000n) having a dynamic range which is different from the dynamic range of the input image, wherein the image color transformer is arranged to receive a luminance mapping function (F_L[P]) to be applied to the pixel luma yielding a resultant luminance (Lmda), and a chrominance mapping function (F_C[Y]) to be applied to the pixel chrominances yielding output chrominances (Cb*, Cr*), - characterized in that the color transformer comprises a scale factor determiner (400) arranged to determine a scale factor (LAM) which is calculated so that for any received luminance mapping function shape the value of the resultant luminance (Lmda) which is obtained by luminance mapping an input pixel luma having a value equal to 0.5, is after multiplying said value of the resultant luminance by the scale factor identical to the luminance which results from applying the inverse of the opto-electrical transfer function to an input pixel luma having a value equal to 0.5; - and which color transformer is arranged to determine an adjusted luminance (Ladj) by multiplying the resultant luminance (Lmda), which is obtained by luminance mapping any input pixel luma, by the scale factor (LAM), and arranged to use the adjusted luminance and the output chrominances to determine the output color (RH,GH,BH).

公开(公告)号：WO2015180854A1

公开(公告)日：2015-12-03

申请号：PCT/EP2015/055831

申请日：2015-03-19

Applicant: KONINKLIJKE PHILIPS N.V.

Inventor： VAN DER VLEUTEN, Renatus, Josephus ,  MERTENS, Mark, Jozef, Willem

IPC: H04N19/30 ,  G06T5/00

CPC classification number: H04N19/98 ,  G06T5/009 ,  G06T9/00 ,  G06T2207/10024 ,  G06T2207/20208 ,  G09G3/2003 ,  G09G5/10 ,  G09G2320/0271 ,  G09G2320/0276 ,  G09G2320/0673 ,  G09G2340/02 ,  G09G2340/06 ,  H04N5/20 ,  H04N7/0117 ,  H04N19/186 ,  H04N19/30 ,  H04N19/44 ,  H04N19/46

Abstract: 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).

Abstract translation: 为了实现良好的HDR图像或视频编码技术，能够产生高动态范围图像以及低动态范围图像，我们发明了一种对高动态范围图像（M_HDR）进行编码的方法，包括以下步骤：将高 通过应用a）将高动态范围图像缩放到例如[0,1]的亮度轴的预定尺度，将动态范围图像转换为较低亮度动态范围（LDR_o）的图像，b）应用灵敏度色调映射， 像素颜色的亮度落在至少包括高动态范围图像中的较暗颜色的子范围内，c）应用伽玛函数，以及d）应用将执行步骤b和c所得到的亮度映射到任意单调递增函数以输出 较低动态范围图像（LDR_o）的亮度; 以及在图像信号（S_im）中输出下部亮度动态范围图像（LDR_o）的像素颜色的编码，并输出编码上述颜色转换的功能行为的图像信号（S_im）作为元数据的值，或值 对于逆函数，哪些元数据允许从较低亮度动态范围图像（LDR_o）重建高动态范围图像（Rec_HDR）。