Method and apparatus for near lossless digital image compression
AssigneeIntel Corporation
InventorsJudith A. Goldstein, Lawrence K. Freytag, Michael Keith
Life of this patent
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Abstract
A method and apparatus for encoding a digital image is disclosed. A difference is calculated between a first sample from a current scan line and a corresponding second sample from a previous scan line. A quantization table level is selected from a quantization table that includes at least one level, and information identifying the selected level is placed into an information stream. A quantizer is selected from the quantization table level based on the calculated difference and information corresponding to the selected quantizer is place into the information stream.
Claims11
A method for encoding a digital image, the method comprising the steps of:
- calculating a difference between a first sample and a second sample;
- selecting a quantization table level from the first quantization table which includes at least one level;
- placing information identifying the selected quantization table level into an information stream;
- selecting a quantizer from the quantization table level based on the difference;
- and
- placing information corresponding to the quantizer into the information stream.
A method for decoding a digital image, the method comprising the steps of:
- providing a decoder quantization table which includes at least one level;
- receiving information identifying a quantization table level, the table level information being received through an information stream;
- selecting a quantization table level;
- receiving information corresponding to a quantizer, the quantizer information previously generated using an encoder quantization table;
- and
- selecting a value from the quantization table level, the value generally representing a difference between a first sample and a second sample.
A computer system, comprising:
- a processor coupled to a bus;
- a main memory coupled to the bus and having stored therein a decoder table;
- and
- an imaging device coupled to the bus, the imaging device having an encoder that includes a first encoder quantization table which has at least one level, calculates a difference between a first sample and a second sample, selects a quantization table level,
- places information corresponding to the selected quantization table level into the information stream, the information stream delivered over the bus,
- selects a quantizer from the quantization table level based on the difference, and
- places information corresponding to the quantizer into the information stream.
Dependencies are inferred from the claim text.