Meta Platforms Technologies, LLC

Microsoft Technology Licensing, LLC

Sharp Laboratories of America, Inc

Facebook Technologies, LLC

Zhi Zhou

Cheng Chang

Richard Lawrence Greene

Richard Webb

Sridhar Srinivasan

Shijun Sun

Gary Joseph Sullivan

Shankar Lakshmi Regunathan

Sudhir K Satpathy

Daniel Schonberg

Seokhoon Kim

In an embodiment, a system includes a buffer configured to store a plurality of pixel blocks of an image, a first processor unit configured to receive a pixel block of the of the plurality of pixel blocks and select whether to separately encode or jointly encode pixel components of the pixel block by computing eigenvalues for the pixel components, a second processor unit configured to compute, responsive to the first processing unit selecting to jointly encode the pixel block, (i) an eigenvector for the pixel components of the pixel block based on the eigenvalues and (ii) endpoints on the eigenvector for encoding the pixel components, an encoder unit configured to encode, responsive to the first processing unit selecting to jointly encode the pixel block, the pixel components of the pixel block jointly based on the eigenvector and the endpoints.

Pixel block encoder capable of jointly encoding pixel channels

A computing system may access first alpha values associated with first pixels in a first pixel region of an image and determine a bit budget for encoding the first alpha values. The computing system may then select a first alpha-encoding mode for the first alpha values to reflect a determination that the first alpha values are all fully transparent or all fully opaque, and encode the first alpha values by storing the selected first alpha-encoding mode as part of a metadata without using the bit budget to encode the first alpha values individually. The computing system may then update a record of unallocated bits available for allocation based on the bit budget unused in the encoding of the first alpha values, and allocate, based on the record of unallocated bits, bits to encode a set of alpha values different from the first alpha values.

Rate controlled image and texture data compression

In one embodiment, a computing system may access color components of a pixel region in an image, and then determine a color variance for each of the color components. The computing system may further determine a desired bit allocation for each of the color components based on the color variance associated with that color component. The computing system may then determine a total bit allocation for the pixel region based on the desired bit allocations for the color components, as well as a number of unallocated bits available for allocation. The computing system may further determine a final bit allocation for each of the color components by allocating the total bit allocation to each of the color components according to the desired bit allocation for each of the color components. The computing system may then encode each of the color components using the associated final bit allocation.

In one embodiment, a computing system may access first alpha values associated with first pixels in a first pixel region of an image and determine a bit budget for encoding the first alpha values. The computing system may then select a first alpha-encoding mode for the first alpha values to reflect a determination that the first alpha values are all fully transparent or all fully opaque, and encode the first alpha values by storing the selected first alpha-encoding mode as part of a metadata without using the bit budget to encode the first alpha values individually. The computing system may then update a record of unallocated bits available for allocation based on the bit budget unused in the encoding of the first alpha values, and allocate, based on the record of unallocated bits, bits to encode a set of alpha values different from the first alpha values.

In one embodiment, a computing system may access a first set of pixel values of an image having a bit depth. The first set of pixel values includes a first subset and a second subset. Each pixel value in the first subset is less than each pixel value in the second subset. The computing system may further determine an overflow range based on a pixel value overflow associated with the bit depth. The overflow range covers a second set of pixel values, which includes (1) the second subset and (2) an overflow representation of the first subset. In response to determining that the overflow range is less than a range covering the first set of pixel values, the computer system may then generate quantization levels corresponding to the overflow range and associate each pixel value of the second set of pixel values with one of the quantization levels.

Methods and systems for image data compression

One or more continuous mappings are defined at a digital media encoder to convert input digital media data in a first high dynamic range format to a second format with a smaller dynamic range than the first format. The encoder converts the input digital media data to the second format with the smaller dynamic range using the continuous mapping and one or more conversion parameters relating to the continuous mapping. The encoder encodes the converted digital media data in a bitstream along with the conversion parameter(s). The conversion parameter(s) enable a digital media decoder to convert the converted digital media data back to the first high dynamic range format from the second format with the smaller dynamic range. Techniques for converting different input formats with different dynamic ranges are described.

High dynamic range data format conversions for digital media

In certain embodiments, overlap operators are applied during encoding and/or decoding of digital media, where the overlap operators have reduced DC gain mismatch and/or DC leakage between interior overlap operators and overlap operators at the edge and/or corner. In other embodiments, information indicating a selected tile boundary option for overlap processing can be encoded and/or decoded. The selected tile boundary option indicates one of a hard tile boundary option and a soft tile boundary option for processing with overlap operators. Overlap transform processing can then be applied based at least in part on the selected tile boundary option.

Reduced DC gain mismatch and DC leakage in overlap transform processing

A one-pass picture-layer rate control (RC) method and system for controlling a video encoder: The bit allocation and determination of quantization parameter (QP) in this rate control method and system are based on a Rate-Quantization (R-Q) scale model. The R-Q model is a linear one, wherein the number of bits per picture is in reverse ratio of quantization scale for that picture. A conversion of exponential-based QP to linear-scaled QP is taken in the calculation of complexity model and determination of QP. The conversion is integer-based and is consistent with the quantization array defined in the H.264 standard.

Growing community of inventors

Issaquah, WA, United States of America

Zhi Zhou