Abstract: A prediction unit (60) for an encoder (24) or decoder (44) implements matrix based intra prediction Input boundary samples for a current block are downsampled to obtain reduced boundary samples for matrix multiplication and/or linear interpolation, or both. In one embodiment, downsampling is performed in a manner that aligns the reduced boundary samples with an output of a matrix multiplication unit of the prediction unit. In other embodiments, downsampling is performed without averaging. The embodiments reduce the complexity of the prediction unit and the latency of the encoder (24) or decoder (44).

Abstract: A computing device (300) for authenticating a user (110), such as a mobile phone, a smartphone, a tablet, or the like, is provided. The computing device is operative to acquire a representation of a melody generated by the user, and authenticate the user in response to determining that the acquired representation of the user-generated melody and a representation of a reference melody fulfil a similarity condition. The user-generated melody may either be vocalized or subvocalized. If the melody is vocalized, the representation is derived from audio data captured by a microphone (102). If the melody is subvocalized, the representation is derived from nerve signals captured by sensors attached to the throat (111) of the user, or from a video sequence acquired from a camera (103), the video sequence capturing one or more body parts (111-115) of the user subvocalizing the melody, by magnifying motions of the one or more body parts which are correlated with the subvocalized melody.

Abstract: The present embodiments introduce a new type of random access point in video bitstreams that can be used for random access operations but can be represented in encoded form at a lower bit-cost as compared to IRAP pictures. The random access point is a dependent random access point (DRAP) picture that is encoded and decoded using an IRAP picture and/or a previous, according to a decoding order, DRAP picture as sole reference picture(s) for the DRAP picture. The DRAP picture is encoded as a trailing picture that may be used for reference and constitutes a random access point in a video bitstream.

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 MIP method (700) for predicting samples of a current block. The method includes storing (s702) a set of MIP weight matrices. The method also includes determining (s704) the width, W, and the height, H, of the current block. The method further includes setting (s706) a mipSizeId variable to 1 as a result of: i) determining that W=4 storing a set of MIP weight matrices and H=16 or ii) determining that W=16 and H=4. The method further includes storing (s708) a value, predModeIntra, that specifies a MIP prediction mode for the current block. The method further includes determining (s710), based on predModeIntra and the value of the mipSizeId variable, a modeId value. And the method further includes selecting (s712), from the set of MIP weight matrices, a MIP weight matrix to be used for the current block, wherein the selection is based on modeId and the value of the mipSizeId variable.

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.