Method and apparatus for encoding and decoding data

An apparatus for encoding data, the apparatus comprising:

• an input unit which receives data;
• a quantization unit which acquires a plurality of quantized coefficients respectively corresponding to a plurality of quantizers by applying the plurality of quantizers to the data, wherein each of the plurality of quantizers has an intrinsic offset value;
• a quantizer determination unit which determines one quantizer from among the plurality of quantizers by using the acquired plurality of quantized coefficients respectively corresponding to the plurality of quantizers;
• and
• a multiplexing unit which generates a data stream by combining a quantized coefficient corresponding to the determined one quantizer, and offset information of the determined one quantizer,
• wherein quantization step sizes of the plurality of quantizers are equal, and offset values of the plurality of quantizers are different from each other.

An apparatus for decoding data, the apparatus comprising:

• a de-multiplexing unit which de-multiplexes, from a data stream, a quantized coefficient and an indicator corresponding to a quantizer;
• a de-quantization unit which determines one de-quantizer from among a plurality of de-quantizers by using the indicator, and acquires reconstructed data by applying the quantized coefficient to the determined one de-quantizer, wherein each of the plurality of de-quantizers has an intrinsic offset value;
• and
• an output unit which outputs the reconstructed data,
• wherein quantization step sizes of the plurality of de-quantizers are equal, and offset values of the plurality of de-quantizers are different from each other.

An apparatus for decoding data, the apparatus comprising:

• a de-multiplexing unit which separates, from a data stream, a quantized coefficient and offset information of a quantizer;
• a de-quantization unit which de-quantizes the quantized coefficient by using the offset information, to acquire reconstructed data;
• and
• an output unit which outputs the reconstructed data.

A method of decoding data, performed by an apparatus for decoding data, the method comprising:

• de-multiplexing, from a data stream, a quantized coefficient and an indicator corresponding to a quantizer;
• determining one de-quantizer from among a plurality of de-quantizers by using the indicator, wherein each of the plurality of de-quantizers has an intrinsic offset value;
• acquiring reconstructed data by applying the quantized coefficient to the determined one de-quantizer;
• and
• outputting the reconstructed data,
• wherein quantization step sizes of the plurality of de-quantizers are equal, and offset values of the plurality of de-quantizers are different from each other.

A method of decoding data, performed by an apparatus for decoding data, the method comprising:

• separating, from a data stream, a quantized coefficient and offset information of a quantizer;
• de-quantizing the quantized coefficient by using the offset information, to acquire reconstructed data;
• and
• outputting the reconstructed data.

A method of encoding data, performed by an apparatus for encoding data, the method comprising:

• acquiring a plurality of quantized coefficients respectively corresponding to a plurality of quantizers by applying the plurality of quantizers to data, wherein each of the plurality of quantizers has an intrinsic offset value;
• determining one quantizer from among the plurality of quantizers by using the acquired plurality of quantized coefficients respectively corresponding to the plurality of quantizers;
• and
• generating a data stream by combining a quantized coefficient corresponding to the determined quantizer, and information corresponding to the determined quantizer,
• wherein quantization step sizes of the plurality of quantizers are equal, and offset values of the plurality of quantizers are different from each other.