Abstract: A processing for a first pixel in a picture comprises setting upper and/or lower limits of a first color component of the first pixel in a first color space to a respective fixed value if a maximum and/or minimum value of the first color component in the first color space results in a color component in a second color space that is below a first value of the color component in the second color space and above a second value of the color component in the second color space. A filtered value is obtained of the first color component and which is equal to or larger than the lower limit and equal to or lower than the upper limit. The processing results in filtered values that are cheaper to encode but that are visibly undistinguishable from the original colors of the pixels.

Abstract: A method for encoding or decoding an image of a video sequence is provided. The method comprises obtaining a set of sample values associated with the image. The method comprises determining a relative location of the current sample value with respect to a virtual boundary. The virtual boundary is defined with respect to a block boundary between the first block of sample values and a second block of sample values. The virtual boundary is parallel with the block boundary and separated from the block boundary by at least one row or column of sample values included in the first block of sample values. The method comprises a filter strength value based on the determined relative location of the current sample value with respect to the virtual boundary. The method comprises filtering the current sample value based on the selected filter strength value.

Abstract: A method for decoding a current block in a current picture of a video bitstream includes decoding, from the video bitstream, a first motion vector for the current block relative to a first reference block of a first reference picture having a first picture order count, and decoding, from the video bitstream, a second motion vector for the current block relative to a second reference block of a second reference picture having a second picture order count. A similarity metric is generated based on a comparison of the first motion vector and the second motion vector. The method further includes determining whether to refine the first motion vector based on the similarity metric, generating a first refined motion vector from the first motion vector, and performing motion compensation to derive a first reference block from the first reference picture using the first refined motion vector.

Abstract: A pixel value of a pixel in a picture of a video sequence is modified by a weighted combination of the pixel value and at least one spatially neighboring pixel value in a filtering. The filtering depends on a pixel distance between the pixel and a neighboring pixel and on a pixel value difference between the pixel and a neighboring pixel value of the neighboring pixel. The filtering is controlled by a spatial parameter and a range parameter. At least one of the spatial parameter and the range parameter depends on at least one of a quantization parameter, a quantization scaling matrix, a transform width, a transform height, a picture width, a picture height and a magnitude of a negative filter coefficient used as part of inter/intra prediction. The embodiments provide a deringing filtering to combat ringing artifacts during video coding.

Abstract: A method for decoding a current block in a current picture of a video bitstream includes decoding, from the video bitstream, a first motion vector for the current block relative to a first reference block of a first reference picture having a first picture order count, and decoding, from the video bitstream, a second motion vector for the current block relative to a second reference block of a second reference picture having a second picture order count. A similarity metric is generated based on a comparison of the first motion vector and the second motion vector. The method further includes determining whether to refine the first motion vector based on the similarity metric, generating a first refined motion vector from the first motion vector, and performing motion compensation to derive a first reference block from the first reference picture using the first refined motion vector.

Abstract: According to a first aspect, a method is provided. The method includes obtaining an M×N array of pixel values an image; determining a weight selection value for position x,y in the M×N array; and using the weight selection value to obtain a weight value for use in a filter for filtering the image. Determining the weight selection value for position x,y (omegax,y) includes: a) retrieving a previously determined weight selection value for position x,y?1 (omegax,y?1); b) retrieving a previously determined alpha value (a) for position x,y?1; c) calculating a delta value (d); and d) calculating omegax,y=omegax,y?1?a+d. Calculating d includes: i) retrieving a first previously determined value (omega_row); i) retrieving a second previously determined value (alpha_row); and ii) calculating d=omega_row?alpha_row+abs(Ax+1,y+1?Ax+1,y+2), wherein Ax+1,y+1 is the value stored in position x+1,y+1 of the array and Ax+1,y+2 is the value stored in position x+1,y+2 of the array.

Abstract: Methods and apparatuses for applying a deblocking to a coding unit in video pictures. In one aspect, the deblocking is applied to sub-block boundaries in the coding unit and to implicit transform unit boundaries in the coding unit.

Abstract: A computing device (200) for authenticating a user (110) is provided. The computing device is operative to display a first text (131) to the user, acquire a representation of the user subvocalizing a part of the first text, derive a user phrasing signature from the acquired representation, and authenticate the user in response to determining that the user phrasing signature and a reference phrasing signature fulfil a similarity condition. Optionally, the computing device may be further operative to determine if the user is authorized to read the first text. Further optionally, the computing device may be operative to reveal obfuscated parts of the first text in response to determining that the user is authorized to read the first text, or to discontinue displaying the first text, or to obfuscate at least part of the first text, in response to determining that the user is not authorized to read the first text.

Abstract: There are provided mechanisms for methods and apparatuses for transform selection in encoding and decoding of video blocks.

Abstract: Methods and apparatuses for video processing. In one aspect, filtering is applied after applying a set of offset values to one or more coefficients. The application of an offset value may be based on a determination as to whether the coefficient meets a threshold value.

Abstract: A computing device for authenticating a user is provided. The computing device is operative to display a first text to the user, acquire a representation of the user subvocalizing a part of the first text, derive a user phrasing signature from the acquired representation, and authenticate the user in response to determining that the user phrasing signature and a reference phrasing signature fulfill a similarity condition. Optionally, the computing device may be further operative to determine if the user is authorized to read the first text. Further optionally, the computing device may be operative to reveal obfuscated parts of the first text in response to determining that the user is authorized to read the first text, or to discontinue displaying the first text, or to obfuscate at least part of the first text, in response to determining that the user is not authorized to read the first text.

Abstract: A refined reconstruction block of a first color component in a picture is determined by at least one of clipping and bilateral filtering a sum of a prediction block of the first color component and a residual of the first color component. A residual block of a second color component is predicted from the refined 5 construction block of the first color component. Applying clipping and/or filtering to the first color component prior to using it in cross-component prediction of the second color component improves and refines predictions or residuals of another color component.

Abstract: A pixel value of a pixel in a picture of a video sequence is modified by a weighted combination of the pixel value and at least one spatially neighboring pixel value in a filtering. The filtering depends on a pixel distance between the pixel and a neighboring pixel and on a pixel value difference between the pixel and a neighboring pixel value of the neighboring pixel. The filtering is controlled by a spatial parameter and a range parameter. The spatial parameter depends on at least one of a width and a height of a transform block, and on at least one of a prediction type of a block of pixels in the picture, a picture type of the picture, and a slice type of a slice in the picture.

Abstract: A method for encoding or decoding an image of a video sequence is provided. The method comprises obtaining a set of sample values associated with the image. The method comprises determining a relative location of the current sample value with respect to a virtual boundary. The virtual boundary is defined with respect to a block boundary between the first block of sample values and a second block of sample values. The virtual boundary is parallel with the block boundary and separated from the block boundary by at least one row or column of sample values included in the first block of sample values. The method comprises a filter strength value based on the determined relative location of the current sample value with respect to the virtual boundary. The method comprises filtering the current sample value based on the selected filter strength value.

Abstract: According to a first aspect, a method is provided. The method includes obtaining an M×N array of pixel values an image; determining a weight selection value for position x,y in the M×N array; and using the weight selection value to obtain a weight value for use in a filter for filtering the image. Determining the weight selection value for position x,y (omegax,y) includes: a) retrieving a previously determined weight selection value for position x,y?1 (omegax,y?1); b) retrieving a previously determined alpha value (a) for position x,y?1; c) calculating a delta value (d); and d) calculating omegax,y=omegax,y?1?a+d. Calculating d includes: i) retrieving a first previously determined value (omega_row); i) retrieving a second previously determined value (alpha_row); and ii) calculating d=omega_row?alpha_row+abs(Ax+1,y+1?Ax+1,y+2), wherein Ax+1,y+1 is the value stored in position x+1,y+1 of the array and Ax+1,y+2 is the value stored in position x+1,y+2 of the array.

Abstract: There are provided mechanisms for methods and apparatuses for transform selection in encoding and decoding.

Abstract: A method of decoding a block of video samples from a video bitstream is provided in which the method includes decoding a DQPRP value, deriving a PQP value for a block having a non-zero residual, decoding a DDQP value for the block, deriving a SDQP value for the block from the DDQP value and the DQPRP value, deriving a block QP value for the block from the SDQP value and the PQP value, decoding at least one non-zero coefficient of the block, deriving values of a residual block for the block by first scaling the at least one non-zero coefficient using the QP value and thereafter applying an inverse transform, deriving values of a prediction block spatial or temporal prediction, and deriving decoded sample values for the block by adding the values of the residual block and the values of the prediction block.

Abstract: A processing for a first pixel in a picture comprises obtaining a lower limit of a first color component of the first pixel in a first color space based on a distance between a color of the first pixel and a first distorted version of the color in a second color space. An upper limit of the first color component in the first color 5 space is obtained based on a distance between the color and a second distorted version of the color in the second color space. A filtered value is obtained of the first color component and which is equal to or larger than the lower limit and equal to or lower than the upper limit. The processing results in filtered values that are cheaper to encode but that are visibly undistinguishable from the original colors of the pixels.

Abstract: An imaging device comprising a first camera with a controllable focus is provided. The imaging device is operative to detect that a user of the imaging device intends to capture an image of an object using the first camera, control the focus of the first camera to assume a target focal length, and capture the image. The target focal length is derived based on a measured accommodation of an eye lens of the user. Further, a contact lens comprising an eye-accommodation detector and a communications module is provided. The contact lens is operative to measure an accommodation of an eye lens to which the contact lens is attached, and transmit, to an imaging device comprising a first camera with a controllable focus, information pertaining to the measured accommodation of the eye lens and/or a focal length of the eye lens corresponding to the measured accommodation.

Abstract: A method of decoding a block of video samples from a video bitstream is provided in which the method includes decoding a DQPRP value, deriving a PQP value for a block having a non-zero residual, decoding a DDQP value for the block, deriving a SDQP value for the block from the DDQP value and the DQPRP value, deriving a block QP value for the block from the SDQP value and the PQP value, decoding at least one non-zero coefficient of the block, deriving values of a residual block for the block by first scaling the at least one non-zero coefficient using the QP value and thereafter applying an inverse transform, deriving values of a prediction block spatial or temporal prediction, and deriving decoded sample values for the block by adding the values of the residual block and the values of the prediction block.