Abstract: Variations of rho-domain rate control for video encoding or other media encoding are presented. For example, in some of the variations, an encoder sets a rho value for a unit of media based at least in part on a bit allocation for the unit. The encoder also computes transform coefficients for the unit using a frequency transform having multiple location-dependent scale factors, sets a value of quantization parameter (“QP”) for the unit using a mapping of QP values to rho values, and uses the value of QP for the unit during quantization of the transform coefficients of the unit. When the QP-rho mapping is determined, a location-independent scale factor that approximates the multiple location-dependent scale factors is used and/or certain scaling operations are integrated, which reduces computational complexity while still supporting accurate rate control decisions. Implementations of such variations of rate control can exploit opportunities for caching and parallel computation.

Abstract: Innovations in encoding of video pictures in a high-resolution chroma sampling format (such as YUV 4:4:4) using a video encoder operating on coded pictures in a low-resolution chroma sampling format (such as YUV 4:2:0) are presented. For example, according to a set of decision rules, high chroma resolution details are selectively encoded on a region-by-region basis such that increases in bit rate (due to encoding of sample values for the high chroma resolution details) happen when and where corresponding increases in chroma resolution are likely to improve quality in noticeable ways. In this way, available encoders operating on coded pictures in the low-resolution chroma sampling format can be effectively used to provide high chroma resolution details.

Abstract: Innovations in encoding of video pictures in a high-resolution chroma sampling format (such as YUV 4:4:4) using a video encoder operating on coded pictures in a low-resolution chroma sampling format (such as YUV 4:2:0) are presented. For example, according to a set of decision rules, high chroma resolution details are selectively encoded on a region-by-region basis such that increases in bit rate (due to encoding of sample values for the high chroma resolution details) happen when and where corresponding increases in chroma resolution are likely to improve quality in noticeable ways. In this way, available encoders operating on coded pictures in the low-resolution chroma sampling format can be effectively used to provide high chroma resolution details.

Abstract: Innovations in encoding of video pictures in a high-resolution chroma sampling format (such as YUV 4:4:4) using a video encoder operating on coded pictures in a low-resolution chroma sampling format (such as YUV 4:2:0) are presented. For example, according to a set of decision rules, high chroma resolution details are selectively encoded on a region-by-region basis such that increases in bit rate (due to encoding of sample values for the high chroma resolution details) happen when and where corresponding increases in chroma resolution are likely to improve quality in noticeable ways. In this way, available encoders operating on coded pictures in the low-resolution chroma sampling format can be effectively used to provide high chroma resolution details.

Abstract: Non-limiting examples of the present disclosure describe detection of gross motion of a region of content. Gross motion of a region of content may be detected. A determination may be made as to a current quality level of the region. Based on detection of the gross motion, residual values may be generated for a progressive update of the region. The residual values are generated using the current quality level of the region as a base to determine a quantization update for a progressive update of the region at a higher quality level as compared with the current quality level of the region. Frame data for the progressive update of the region may be encoded. The frame data may comprise the residual values and motion vectors for progressive update of the region. The frame data may be transmitted for decoding. Other examples are also described.

Abstract: Techniques are described for performing multi-stage image classification. For example, multi-stage image classification can comprise a first classification stage and a second classification stage. The first classification stage can determine an overall classification for an input image (e.g., based on a relative entropy result calculated for the input image). The second classification stage can be performed by dividing the image into a plurality of blocks and classifying individual blocks, or groups of blocks, based on a classification model that is specific to the overall classification of the image determined in the first classification stage.

Abstract: Innovations are provided for encoding and/or decoding video and/or image content using transform coefficient level gradual updating. Transform coefficient level gradual updating can be applied by encoding (or decoding) different subsets of the transform coefficients for the blocks, macroblocks, or other coding unit for each of a sequence of pictures. For example, a first subset of the transform coefficients of the blocks of a first picture can be encoded with the first picture, a second subset of the transform coefficients of the blocks of a second picture can be encoded with the second picture, and so on. A decoder can reconstruct pictures with increasing quality by receiving additional subsets of the transform coefficients.

Abstract: Innovations in encoding and decoding of video pictures in a high-resolution chroma sampling format (such as YUV 4:4:4) using a video encoder and decoder operating on coded pictures in a low-resolution chroma sampling format (such as YUV 4:2:0) are presented. For example, high chroma resolution details are selectively encoded on a region-by-region basis. Or, as another example, coded pictures that contain sample values for low chroma resolution versions of input pictures and coded pictures that contain sample values for high chroma resolution details of the input pictures are encoded as separate sub-sequences of a single sequence of coded pictures, which can facilitate effective motion compensation. In this way, available encoders and decoders operating on coded pictures in the low-resolution chroma sampling format can be effectively used to provide high chroma resolution details.

Abstract: Techniques are described for performing multi-stage image classification. For example, multi-stage image classification can comprise a first classification stage and a second classification stage. The first classification stage can determine an overall classification for an input image (e.g., based on a relative entropy result calculated for the input image). The second classification stage can be performed by dividing the image into a plurality of blocks and classifying individual blocks, or groups of blocks, based on a classification model that is specific to the overall classification of the image determined in the first classification stage.

Abstract: Techniques are described for performing multi-stage image classification. For example, multi-stage image classification can comprise a first classification stage and a second classification stage. The first classification stage can determine an overall classification for an input image (e.g., based on a relative entropy result calculated for the input image). The second classification stage can be performed by dividing the image into a plurality of blocks and classifying individual blocks, or groups of blocks, based on a classification model that is specific to the overall classification of the image determined in the first classification stage.

Abstract: Techniques are described for performing multi-stage image classification. For example, multi-stage image classification can comprise a first classification stage and a second classification stage. The first classification stage can determine an overall classification for an input image (e.g., based on a relative entropy result calculated for the input image). The second classification stage can be performed by dividing the image into a plurality of blocks and classifying individual blocks, or groups of blocks, based on a classification model that is specific to the overall classification of the image determined in the first classification stage.

Abstract: Innovations in the area of filtering in and around high chroma resolution regions of output pictures are presented. For example, a video processing tool applies a recovery filter in a high chroma resolution region of an output picture, which compensates for anti-aliasing filtering previously performed during chroma sub-sampling, but skips application of the recovery filter in a low chroma resolution region of the output picture. Or, a video processing tool applies a deblocking filter to chroma sample values at a boundary between a low chroma resolution region and high chroma resolution region in the output picture, which can mitigate perceptible distortion at the boundary. Or, a video processing tool selectively applies a deringing filter to chroma sample values in a high chroma resolution region of the output picture, which can mitigate perceptible distortion due to low quality coding of high chroma resolution details.

Abstract: Innovations in encoding and decoding of video pictures in a high-resolution chroma sampling format (such as YUV 4:4:4) using a video encoder and decoder operating on coded pictures in a low-resolution chroma sampling format (such as YUV 4:2:0) are presented. For example, high chroma resolution details are selectively encoded on a region-by-region basis. Or, as another example, coded pictures that contain sample values for low chroma resolution versions of input pictures and coded pictures that contain sample values for high chroma resolution details of the input pictures are encoded as separate sub-sequences of a single sequence of coded pictures, which can facilitate effective motion compensation. In this way, available encoders and decoders operating on coded pictures in the low-resolution chroma sampling format can be effectively used to provide high chroma resolution details.

Abstract: Innovations are provided for encoding and/or decoding video and/or image content using transform coefficient level gradual updating. Transform coefficient level gradual updating can be applied by encoding (or decoding) different subsets of the transform coefficients for the blocks, macroblocks, or other coding unit for each of a sequence of pictures. For example, a first subset of the transform coefficients of the blocks of a first picture can be encoded with the first picture, a second subset of the transform coefficients of the blocks of a second picture can be encoded with the second picture, and so on. A decoder can reconstruct pictures with increasing quality by receiving additional subsets of the transform coefficients.

Abstract: Innovations in encoding of video pictures in a high-resolution chroma sampling format (such as YUV 4:4:4) using a video encoder operating on coded pictures in a low-resolution chroma sampling format (such as YUV 4:2:0) are presented. For example, according to a set of decision rules, high chroma resolution details are selectively encoded on a region-by-region basis such that increases in bit rate (due to encoding of sample values for the high chroma resolution details) happen when and where corresponding increases in chroma resolution are likely to improve quality in noticeable ways. In this way, available encoders operating on coded pictures in the low-resolution chroma sampling format can be effectively used to provide high chroma resolution details.

Abstract: Variations of rho-domain rate control for video encoding or other media encoding are presented. For example, in some of the variations, an encoder sets a rho value for a unit of media based at least in part on a bit allocation for the unit. The encoder also computes transform coefficients for the unit using a frequency transform having multiple location-dependent scale factors, sets a value of quantization parameter (“QP”) for the unit using a mapping of QP values to rho values, and uses the value of QP for the unit during quantization of the transform coefficients of the unit. When the QP-rho mapping is determined, a location-independent scale factor that approximates the multiple location-dependent scale factors is used and/or certain scaling operations are integrated, which reduces computational complexity while still supporting accurate rate control decisions. Implementations of such variations of rate control can exploit opportunities for caching and parallel computation.