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US 9,883,180 B2Granted
Bounded rate near-lossless and lossless image compression
AssigneeAvago Technologies General IP (Singapore) Pte. Ltd.
InventorsAlexander Garland MacInnis, Frederick George Walls
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Abstract
A system adjusts the quantization parameter used to encode an image sample (e.g., pixel component). The system accesses a quantization parameter for encoding a current image pixel from an implicit rate control and obtains a measure of another image sample within a particular distance from the sample. When the measure meets a predetermined criterion, the system adjusts the quantization parameter, encodes the pixel after adjusting the quantization parameter, and explicitly indicates the adjusting of the quantization parameter to a decoding system.
Claims19
A method comprising:
- accessing a quantization parameter, from an implicit rate control, for encoding a current image sample;
- obtaining a measure of another image sample within a particular distance from the current image sample;
- adjusting the quantization parameter;
- encoding a pixel after adjusting the quantization parameter;
- when the measure meets a predetermined criterion, setting an operational mode bit to a first value to indicate an explicit encoding parameter determination and separately explicitly indicating the adjusting of the quantization parameter to a decoding system by specifying a change to the quantization parameter;
- and
- when the measure does not meet the predetermined criterion, implicitly signaling the quantization parameter to the decoding system by forgoing explicit indication of the adjusting of the quantization parameter and setting the operational mode bit to a second value to indicate an implicit encoding parameter determination.
4 more elements
A system comprising:
- buffer circuitry configured to store a first image sample;
- and
- encoding circuitry in communication with the buffer circuitry and configured to:
- obtain a quantization parameter for encoding the first image sample, the quantization parameter determined according to an implicit rate control algorithm;
- adjust the quantization parameter to obtain an adjusted quantization parameter;
- encode, into a compressed data stream, the first image sample using the adjusted quantization parameter;
- obtain a measure of a second image sample within a particular distance from the first image sample;
- when the measure meets a predetermined criterion, insert an explicit quantization indication into the compressed data stream, the explicit quantization indication specifying an adjustment to the quantization parameter determined according to the implicit rate algorithm and the explicit quantization indication separately comprising a bit set to indicate an explicit quantization parameter determination;
- and
- when the measure does not meet the predetermined criterion, implicitly signal the adjustment to the quantization parameter by forgoing explicit indication of the adjustment.
7 more elements
A product comprising:
- a machine-readable medium other than a transitory signal;
- and
- instructions stored on the machine-readable medium, the instructions, when executed, configured to cause a processor to:
- responsive to an implicit rate control, apply an adjustment to a quantization parameter;
- after applying the adjustment, encode a current pixel in accord with the adjustment;
- obtain a measure of second pixel within a particular distance from the current pixel;
- after encoding the pixel and when the measure meets a predetermined criterion, insert an explicit quantization indicator into a data stream including an encoding of the pixel, the explicit quantization indicator specifying the adjustment to the quantization parameter and the explicit quantization indicator comprising a bit that indicates an explicit quantization parameter encoding;
- and
- when the measure does not meet the predetermined criterion, implicitly signal the adjustment to the quantization parameter by forgoing explicit indication of the adjustment.
6 more elements
Dependencies are inferred from the claim text.