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公开(公告)号：US10218917B2
公开(公告)日：2019-02-26
申请号：US14903294
申请日：2014-07-01
IPC分类号： G06K9/36 , H04N5/235 , H04N19/186 , H04N5/202 , H04N9/804
摘要： To enable better encoding of the currently starting to appear high dynamic range images for use in full high dynamic range technical systems (containing an HDR display, and e.g. in an HDR grading application), we invented a method of constructing a code allocation function for allocating pixel colors having pixel luminances to codes encoding such pixel luminances, in which the step of determining the code allocation function to be applied to at least one color coordinate of the pixel to obtain a code value, comprises constructing that function out of at least two partial functions, and similar methods at a receiving side, and apparatuses, and signals for communicating between the two sites.
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公开(公告)号：US10217198B2
公开(公告)日：2019-02-26
申请号：US15538808
申请日：2015-12-22
发明人： Renatus Josephus Van Der Vleuten , Jeroen Hubert Christoffel Jacobus Stessen , Mark Jozef Willem Mertens
IPC分类号： H04N5/235 , G06T5/00 , H04N9/69 , H04N19/182 , H04N19/98
摘要： For obtaining an good yet easy to use 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_in) 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 2, comprising: a maximum determining unit (101) arranged to calculate a maximum (M) of color components of the input color, the color components at least comprising a red, green and blue component;—a uniformization unit (201) arranged to apply a function (FP) to the maximum (M) as input, which function has a logarithmic shape and was predetermined to be of a fixed shape enabling to transform a linear input to a more perceptually uniform output variable (u); a function application unit (203) arranged to receive a functional shape of a function, which was specified previously by a human color grader, and apply the function to the uniform output variable (u), yielding a transformed uniform value (TU); a linearization unit (204) arranged to transform the transformed uniform value (TU) to a linear domain value (LU); a multiplication factor determination unit (205) arranged to determine a multiplication factor (a) being equal to the linear domain value (LU) divided by the maximum (M); and a multiplier (104) arranged to multiply at least three linear color components (R,G,B) by the multiplication factor (a), yielding the output color.
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公开(公告)号：US10194162B2
公开(公告)日：2019-01-29
申请号：US14903630
申请日：2014-06-30
发明人： Renatus Josephus Van Der Vleuten , Jeroen Hubert Christoffel Stessen , Johannes Gerardus Rijk Van Mourik
摘要： To enable better encoding of the currently starting to appear high dynamic range images for use in full high dynamic range technical systems (containing an HDR display, and e.g. in an HDR grading application of a HDR movie), we invented a method of encoding a high dynamic range image, comprising the steps of: —inputting pixel colors of an input high dynamic range image, wherein the pixel colors have information of a luminance and a chromaticity; —applying an inverse of a mapping function to derive a luma code (v) of the luminance of a pixel color, which mapping function is predetermined as comprising a first partial function which is defined as (I), in which rho is a tuning constant, and v is the luma code corresponding to a luminance to be encoded, and a second partial mapping defined as L=LmPγ in which Lm is a peak luminance of a predefined reference display, and gamma is a constant which is preferably equal to 2.4, —outputting a matrix of pixels having a color encoding comprising the luma codes.
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公开(公告)号：US09230509B2
公开(公告)日：2016-01-05
申请号：US14402135
申请日：2013-09-17
CPC分类号： G09G5/02 , G06T3/0056 , G06T5/002 , G09G2320/0271 , G09G2320/066 , G09G2360/16 , H04N1/6027
摘要： To be able to do good color mapping between color encodings for gamuts with considerably different luminance dynamic range while not introducing significant color errors, we describe an image color processing apparatus (201) arranged to transform an input color (L,x,y) of a pixel specified in a color representation corresponding to a first luminance dynamic range into an output color (L*,x,y) of a pixel specified in a color representation corresponding to a second luminance dynamic range, which first and second dynamic ranges differ in extent by at least a multiplicative factor 1.5, comprising a tone mapping deformation unit (203) arranged to determine on the basis of an input tone mapping (301) and a quantity linearly related to the luminance (L) of the input color, an adjusted output luminance (L*, 309), wherein the determining is arranged so that the adjusted output luminance (L*, 309) obtained by applying the input tone mapping to the input luminance (L) of all possible input luminances in its extent of valid values [0,1] giving the highest output (L*,L_HDR), is not higher than a maximum luminance Lmax(x,y) which for the chromatic coordinates (x,y) of the input color is maximally achievable in the gamut corresponding to the second luminance dynamic range for those chromatic coordinates (x,y).
摘要翻译： 为了能够在颜色编码与亮度动态范围相当不同的颜色编码之间进行良好的颜色映射，同时不引入显着的颜色误差，我们描述了一种图像颜色处理装置（201），其被设置为将输入颜色（L，x，y） 将与第一亮度动态范围对应的颜色表示中指定的像素指定为对应于第二亮度动态范围的颜色表示中指定的像素的输出颜色（L *，x，y），第一和第二动态范围在 至少乘以一个乘法因子1.5，包括一个色调映射变形单元（203），它被配置为基于输入色调映射（301）和与输入颜色的亮度（L）线性相关的量来确定， 输出亮度（L *，309），其中所述确定被布置成使得通过将所输入的色调映射到所有可能的输入亮度的输入亮度（L）而获得的经调整的输出亮度（L *，309） 给出最高输出（L *，L_HDR）的有效值[0,1]程度的肛门不高于输入颜色的色坐标（x，y）的最大亮度Lmax（x，y） 在对应于这些色坐标（x，y）的第二亮度动态范围的色域中最大可实现。
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公开(公告)号：US11928803B2
公开(公告)日：2024-03-12
申请号：US16251627
申请日：2019-01-18
IPC分类号： G06T5/50 , G06T11/00 , G09G3/20 , G09G5/00 , G09G5/10 , G11B20/10 , G11B27/10 , G11B27/32 , H04N7/00 , H04N9/68
CPC分类号： G06T5/92 , G06T5/50 , G06T11/001 , G09G3/2003 , G09G5/006 , G09G5/10 , G11B20/10 , G11B27/105 , G11B27/329 , H04N7/00 , H04N9/68 , G06T2207/20208 , G09G2320/0271 , G09G2320/0606 , G09G2320/0613 , G09G2320/066 , G09G2340/06 , G09G2360/144 , G09G2370/047
摘要： An image processing apparatus comprises a receiver (201) for receiving an image signal which comprises at least an encoded image and a target display reference. The target display reference is indicative of a dynamic range of a target display for which the encoded image is encoded. A dynamic range processor (203) generates an output image by applying a dynamic range transform to the encoded image in response to the target display reference. An output (205) then outputs an output image signal comprising the output image, e.g. to a suitable display. The dynamic range transform may furthermore be performed in response to a display dynamic range indication received from a display. The invention may be used to generate an improved High Dynamic Range (HDR) image from e.g. a Low Dynamic Range (LDR) image, or vice versa.
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公开(公告)号：US11533516B2
公开(公告)日：2022-12-20
申请号：US16985391
申请日：2020-08-05
IPC分类号： G06V10/00 , H04N19/98 , G09G3/20 , H04N19/30 , H04N19/46 , G09G5/10 , H04N5/20 , G06T9/00 , H04N19/186 , H04N19/44 , G06T5/00 , H04N7/01
摘要： 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).
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公开(公告)号：US11423523B2
公开(公告)日：2022-08-23
申请号：US17152825
申请日：2021-01-20
IPC分类号： G06T5/00 , G06T5/50 , H04N9/68 , G11B20/10 , G11B27/10 , G11B27/32 , G09G5/00 , H04N7/00 , G09G5/10 , G06T11/00 , G09G3/20
摘要： An image processing apparatus comprises a receiver (201) for receiving an image signal comprising an encoded image. Another receiver (1701) receives a data signal from a display (107) where the data signal comprises a data field that comprises a display dynamic range indication of the display (107). The display dynamic range indication comprises at least one luminance specification for the display. A dynamic range processor (203) is arranged to generate an output image by applying a dynamic range transform to the encoded image in response to the display dynamic range indication. An output (205) outputs an output image signal comprising the output image to the display. The transform may furthermore be performed in response to a target display reference indicative of a dynamic range of display for which the encoded image is encoded. The invention may be used to generate an improved High Dynamic Range (HDR) image from e.g. a Low Dynamic Range (LDR) image, or vice versa.
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公开(公告)号：US10728560B2
公开(公告)日：2020-07-28
申请号：US16071929
申请日：2017-01-27
IPC分类号： H04N19/186 , H04N19/80 , H04N19/85 , G09G5/02 , H04N19/86 , H04N5/20 , H04N9/67 , H04N9/68 , H04N19/117 , H04N19/59 , G09G5/10 , H04N19/182 , H04N19/98
摘要： 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.
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公开(公告)号：US10419767B2
公开(公告)日：2019-09-17
申请号：US15119735
申请日：2015-02-12
发明人： Jeroen Hubert Christoffel Stessen , Renatus Josephus Van Der Vleuten , Johannes Gerardus Rijk Van Mourik , Rutger Nijland
IPC分类号： H04N9/77 , H04N19/186 , H04N1/64 , H04N9/67 , H04N19/44
摘要： Because we needed a new improved and very different color encoding space for being able to faithfully encode the presently emerging high dynamic range video for good quality rendering on emerging HDR displays such as the SIM2 display, the video encoder (300) with an input (308) to obtain a video from a video source (301) wherein pixel colors are encoded in an (XYZ) color encoding, the video encoder comprising an opto-electronic conversion unit (304) arranged to convert the luminances (Y) of the pixel colors into lumas (Y′) with a predetermined code allocation function (F), characterized in that the video encoder comprises a chromaticity determination unit (310), which is arranged to encode chromaticities (u″,v″) of pixel colors with lumas (Y′) below a predetermined threshold luma (E′) with a mathematical chromaticity definition which yields a maximum encodable saturation (S_bL) for a particular hue for pixel colors with a luma below the predetermined threshold luma (E′) which is lower than a maximum encodable saturation (S_bH) for the particular hue for a pixel color with a luma above the predetermined threshold luma (E′), and a constant maximum encodable saturation (S_bH) for pixels with colors of a particular hue and a luma equal to or larger than the predetermined threshold luma (E′).
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