公开(公告)号：US11463733B2

公开(公告)日：2022-10-04

申请号：US16970499

申请日：2019-02-15

Applicant: Google LLC

Inventor： Jyrki Alakuijala ,  Robert Obryk ,  Evgenii Kliuchnikov ,  Zoltan Szabadka ,  Jan Wassenberg ,  Minttu Alakuijala ,  Lode Vandevenne

IPC: H04N19/65 ,  H04N19/124 ,  H04N19/18 ,  H04N19/184 ,  H04N19/85

Abstract: The loss of image quality during compression is controlled using a sequence of quality control metrics. The sequence of quality control metrics is selected for quantizing transform coefficients within an area of the image based on an error level definition. Candidate bit costs are then determined by quantizing the transform coefficients according to the error level definition or a modified error level and the sequence of quality control metrics. Where the candidate bit cost resulting from using the modified error level is lower than the candidate bit cost resulting from using the error level definition, the transform coefficients are quantized according to the modified error level and the sequence of quality control metrics. Otherwise, the transform coefficients are quantized based on the error level definition and according to the sequence of quality control metrics.

公开(公告)号：US11669553B2

公开(公告)日：2023-06-06

申请号：US16706110

申请日：2019-12-06

Applicant: GOOGLE LLC

Inventor： Jyrki Antero Alakuijala ,  Lode Vandevenne

IPC: G06F16/31 ,  G06F16/182 ,  G06F40/205 ,  G06F40/274 ,  G06F9/46 ,  H03M13/15 ,  H03M13/37

CPC classification number: G06F16/313 ,  G06F9/466 ,  G06F16/182 ,  G06F40/205 ,  G06F40/274 ,  H03M13/15 ,  H03M13/37

Abstract: An context-based encoding mechanism uses a predetermined number of bytes in a previous segment of a file to determine a context for the current segment. The current segment is encoded using a dictionary that corresponds to the determined context. An example method includes determining, for a first segment in a data file, a first context state based on a first context segment within the data file that precedes the first segment, identifying a first indexed dictionary from a plurality of indexed dictionaries based on the first context state, and encoding the first segment using the identified first indexed dictionary.

公开(公告)号：US20200351520A1

公开(公告)日：2020-11-05

申请号：US16402297

申请日：2019-05-03

Applicant: GOOGLE LLC

Inventor： Thomas Fischbacher ,  Lode Vandevenne

IPC: H04N19/625 ,  H04N19/105 ,  H04N19/176

Abstract: A method for encoding a block of a frame. The method includes receiving the block that is in the spatial domain; selecting, based on a border that crosses the block, a set of basis functions for transforming the block to a transform domain; transforming the block using the set of basis functions to obtain a transform block; encoding, in a compressed bitstream, an indication of the set of basis functions; and encoding, in the compressed bitstream, the transform block.

公开(公告)号：US20200329240A1

公开(公告)日：2020-10-15

申请号：US16858802

申请日：2020-04-27

Applicant: GOOGLE LLC

Inventor： Jyrki Alakuijala ,  Lode Vandevenne ,  Thomas Fischbacher

IPC: H04N19/117 ,  H04N19/137 ,  H04N19/176 ,  H04N19/182 ,  H04N19/86

Abstract: An image block is coded using entropy-inspired directional filtering. During encoding, intensity differences are determined for at least some pixels of an image block based on neighboring pixels of respective ones of the at least some pixels. Angles are estimated for each of those pixels based on the intensity differences. A main filtering direction of the image block is then determined based on the estimated angles. The image block is filtered according to the main filtering direction to remove artifacts along oblique edges associated with the image block. The filtered image block is then encoded to an encoded image. During decoding, an angular map indicating angles estimated for pixels of an encoded image block is received and used to determine the main filtering direction of the image block. The image block can then be filtered according to the main filtering direction and then output for display or storage.

公开(公告)号：US20230016253A1

公开(公告)日：2023-01-19

申请号：US17955788

申请日：2022-09-29

Applicant: GOOGLE LLC

Inventor： Jyrki Alakuijala ,  Robert Obryk ,  Evgenii Kliuchnikov ,  Zoltan Szabadka ,  Jan Wassenberg ,  Minttu Alakuijala ,  Lode Vandevenne

IPC: H04N19/65 ,  H04N19/124 ,  H04N19/18 ,  H04N19/184 ,  H04N19/85

Abstract: The loss of image quality during compression is controlled using a sequence of quality control metrics. The sequence of quality control metrics is selected for quantizing transform coefficients within an area of the image based on an error level definition. Candidate bit costs are then determined by quantizing the transform coefficients according to the error level definition or a modified error level and the sequence of quality control metrics. Where the candidate bit cost resulting from using the modified error level is lower than the candidate bit cost resulting from using the error level definition, the transform coefficients are quantized according to the modified error level and the sequence of quality control metrics. Otherwise, the transform coefficients are quantized based on the error level definition and according to the sequence of quality control metrics.

公开(公告)号：US20210084339A1

公开(公告)日：2021-03-18

申请号：US16970499

申请日：2019-02-15

Applicant: Google LLC

Inventor： Jyrki Alakuijala ,  Robert Obryk ,  Evgenii Kliuchnikov ,  Zoltan Szabadka ,  Jan Wassenberg ,  Minttu Alakuijala ,  Lode Vandevenne

IPC: H04N19/65 ,  H04N19/124 ,  H04N19/18 ,  H04N19/184 ,  H04N19/85

Abstract: The loss of image quality during compression is controlled using a sequence of quality control metrics. The sequence of quality control metrics is selected for quantizing transform coefficients within an area of the image based on an error level definition. Candidate bit costs are then determined by quantizing the transform coefficients according to the error level definition or a modified error level and the sequence of quality control metrics. Where the candidate bit cost resulting from using the modified error level is lower than the candidate bit cost resulting from using the error level definition, the transform coefficients are quantized according to the modified error level and the sequence of quality control metrics. Otherwise, the transform coefficients are quantized based on the error level definition and according to the sequence of quality control metrics.

公开(公告)号：US20240276018A1

公开(公告)日：2024-08-15

申请号：US18643085

申请日：2024-04-23

Applicant: GOOGLE LLC

Inventor： Jyrki Alakuijala ,  Robert Obryk ,  Evgenii Kliuchnikov ,  Zoltan Szabadka ,  Jan Wassenberg ,  Minttu Alakuijala ,  Lode Vandevenne

IPC: H04N19/65 ,  H04N19/124 ,  H04N19/18 ,  H04N19/184 ,  H04N19/85

CPC classification number: H04N19/65 ,  H04N19/124 ,  H04N19/18 ,  H04N19/184 ,  H04N19/85

Abstract: The loss of image quality during compression is controlled using a sequence of quality control metrics. The sequence of quality control metrics is selected for quantizing transform coefficients within an area of the image based on an error level definition. Candidate bit costs are then determined by quantizing the transform coefficients according to the error level definition or a modified error level and the sequence of quality control metrics. Where the candidate bit cost resulting from using the modified error level is lower than the candidate bit cost resulting from using the error level definition, the transform coefficients are quantized according to the modified error level and the sequence of quality control metrics. Otherwise, the transform coefficients are quantized based on the error level definition and according to the sequence of quality control metrics.

公开(公告)号：US11212527B2

公开(公告)日：2021-12-28

申请号：US16858802

申请日：2020-04-27

Applicant: GOOGLE LLC

Inventor： Jyrki Alakuijala ,  Lode Vandevenne ,  Thomas Fischbacher

IPC: H04N19/137 ,  H04N19/176 ,  H04N19/182 ,  H04N19/117 ,  H04N19/86

Abstract: An image block is coded using entropy-inspired directional filtering. During encoding, intensity differences are determined for at least some pixels of an image block based on neighboring pixels of respective ones of the at least some pixels. Angles are estimated for each of those pixels based on the intensity differences. A main filtering direction of the image block is then determined based on the estimated angles. The image block is filtered according to the main filtering direction to remove artifacts along oblique edges associated with the image block. The filtered image block is then encoded to an encoded image. During decoding, an angular map indicating angles estimated for pixels of an encoded image block is received and used to determine the main filtering direction of the image block. The image block can then be filtered according to the main filtering direction and then output for display or storage.

公开(公告)号：US11122297B2

公开(公告)日：2021-09-14

申请号：US16402297

申请日：2019-05-03

Applicant: GOOGLE LLC

Inventor： Thomas Fischbacher ,  Lode Vandevenne

IPC: H04N19/176 ,  H04N19/625 ,  H04N19/105

Abstract: A method for encoding a block of a frame. The method includes receiving the block that is in the spatial domain; selecting, based on a border that crosses the block, a set of basis functions for transforming the block to a transform domain; transforming the block using the set of basis functions to obtain a transform block; encoding, in a compressed bitstream, an indication of the set of basis functions; and encoding, in the compressed bitstream, the transform block.