Abstract: 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.

Abstract: 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. This method allows—in line with applicant's technical approach that HDR images should actually be communicated as a spectrum of differently regraded different dynamic range images of the same scene, e.g.

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: 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.

Abstract: 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

Abstract: 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=LmP? 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.

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 f

Abstract: Encoding a high dynamic range image (M_HDR), comprising: 1. converting the high dynamic range image to an image of lower luminance dynamic range (LDR_o) by applying the acts of: a) scaling the high dynamic range image to a predetermined scale of the luma axis such as [0,1], b) 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) a gamma function, and d) applying an arbitrary monotonically increasing function mapping the lumas resulting from performing the acts b and c to output lumas of the lower dynamic range image (LDR_o); and 2. outputting in an image signal (S_im) a codification of the pixel colors of the lower luminance dynamic range image (LDR_o), and 3.

Abstract: 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

Abstract: 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.

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 func

Abstract: 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

Abstract: 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, we present around that new color space various new decoders which allow simplified processing, in particular the handling of all achromatic direction (i.e. luminance) optimization separate from the chromatic processing, and increased quality of the reconstructed HDR images. This is realized by a video decoder (350) having an input (358) for receiving a video signal (S_im) transmitted over a video transmission system or received on a video storage product, in which pixel colors are encoded with an achromatic luma (Y?) coordinate and two chromaticity coordinates (u?,v?), the video decoder comprising a scaling unit (356) arranged to transform the chromaticity colors into a luminance-dependent chrominance color representation, by scaling with the achromatic luma.

Abstract: The present invention relates to a method of encoding blocks of values, e.g. DCT blocks, generated in accordance with an image compression scheme. The values are expressed as a set of bit planes, each bit plane comprising, for the values, all bits with a specific significance. In each bit plane at least one parameter is determined (7) in accordance with a predetermined definition, the parameter defining a partition of the bits in the bit plane which encloses all set bits. All bits in the partition are transferred (8) to a bit stream that may be truncated. This provides a method with low complexity. The invention further relates to a corresponding encoding device, a corresponding decoding device, and a corresponding bit-stream.

Abstract: 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=LmP65 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method and device for encoding an image into a scalable bitstream, the method including acts of dividing the Image in image blocks; encoding each image block in accordance with one of a plurality of different encoding modes, to obtain corresponding block bitstreams comprising one or more types of data representative of said encoding mode; and forming the scalable bitstream by iteratively scanning the block bitstreams, each scan including acts of: selecting at least one of said types of data, including in the scalable bitstream data of the selected types from the block bitstreams, and including in the scalable bitstream flags indicating the selected types of data.

Abstract: The invention relates to a bit-plane coding method of signals, for example, an image or video signal in the DCT transform domain. The bit planes of the DCT blocks are transmitted bit-plane by bit-plane in order of significance. As each plane contains more signal energy than the lower significant layers together, the resulting bitstream is scalable in the sense that it may be truncated at any position. The later the bitstream is truncated, the smaller the residual error when the image is reconstructed. For each bit plane, a zone or partition of bit plane is created that encompasses all the non-zero bits of the DCT coefficients in that bit plane. The partition is created in accordance with a strategy that is selected from a number of options in dependence of the content of the overall signal and/or the actual bit plane. A different zoning strategy may be used for natural images than for graphic content, and the strategy may vary from bitplane to bitplane.