Method and apparatus for dynamically adjusting quantization offset values
AssigneeSharp Laboratories of America, Inc.
InventorShijun Sun
Life of this patent
Estimating the term…
Abstract
An encoding scheme dynamically adjusts a quantization rounding offset parameter used for encoding pictures according to statistics of previously encoded pictures of similar type. A look-up table can be used to store different relative quantization rounding offset parameters associated with different numbers of bits required to encode the pictures. The dynamically adjusted quantization rounding offset scheme achieves better coding performance at high bit rates. In one example, the dynamic quantization offset values are applied to a Uniform-Reconstruction-Quantizer (URQ) used for Laplacian sources.
Claims18
An encoder, comprising:
- encoder circuitry to identify entropy values associated with input data and dynamically identify relative quantization offset values associated with the identified entropy, the encoder circuitry to encode the same or other input data using the dynamically identified relative quantization offset values;
- and
- a quantization offset look-up table to associate the identified entropy values with the different relative quantization offset values, the encoder circuitry to use the identified entropy values as inputs to the lookup table and to use the associated relative quantization offset values output from the look-up table to adjust quantization threshold values when quantizing the input data.
A method for quantizing data, comprising:
- encoding a current picture;
- identifying an amount of signal variance while encoding the current picture;
- accessing a look-up table, populated with relative quantization offset parameters associated with different amounts of signal variance, to identify a relative quantization offset parameter associated with the identified amount of signal variance;
- and
- using the identified relative quantization offset parameter from the look-up table to adjust quantization threshold values when encoding a next picture.
An electronic medium including instructions that, when executed by a processor, cause the processor to:
- encode a current picture;
- identify an amount of signal variance while encoding the current picture;
- access a look-up table, populated with relative quantization offset parameters associated with different amounts of signal variance, to identify a relative quantization offset parameter associated with the identified amount of signal variance;
- and
- use the identified relative quantization offset parameter from the look-up table to adjust quantization threshold values when encoding a next picture.
Dependencies are inferred from the claim text.