**ISO/IEC 10918-1 : 1993(E)**

**3.1.82**

**lossless:**

A descriptive term for encoding and decoding processes and procedures in which the output of the

decoding procedure(s) is identical to the input to the encoding procedure(s).

**3.1.83**

**lossless coding:**

The mode of operation which refers to any one of the coding processes defined in this

Specification in which all of the procedures are lossless (see Annex H).

**3.1.84**

**lossy:**

A descriptive term for encoding and decoding processes which are not lossless.

**3.1.85**

**marker:**

A two-byte code in which the first byte is hexadecimal FF (X'FF') and the second byte is a value

between 1 and hexadecimal FE (X'FE').

**3.1.86**

**marker segment:**

A marker and associated set of parameters.

**3.1.87**

**MCU-row:**

The smallest sequence of MCU which contains at least one line of samples or one block-row from

every component in the scan.

**3.1.88**

**minimum coded unit; MCU:**

The smallest group of data units that is coded.

**3.1.89**

**modes (of operation):**

The four main categories of image coding processes defined in this Specification.

**3.1.90**

**more probable symbol; MPS:**

For a binary decision, the decision value which has the larger probability.

**3.1.91**

**non-differential frame:**

The first frame for any components in a hierarchical encoder or decoder. The

components are encoded or decoded without subtraction from reference components. The term refers also to any frame in

modes other than the hierarchical mode.

**3.1.92**

**non-interleaved:**

The descriptive term applied to the data unit processing sequence when the scan has only one

component.

**3.1.93**

**parameters: **

Fixed length integers 4, 8 or 16 bits in length, used in the compressed data formats.

**3.1.94**

**point transform:**

Scaling of a sample or DCT coefficient.

**3.1.95**

**precision:**

Number of bits allocated to a particular sample or DCT coefficient.

**3.1.96**

**predictor:**

A linear combination of previously reconstructed values (in lossless mode coding).

**3.1.97**

**probability estimation state machine:**

An interlinked table of probability values and indices which is used to

estimate the probability of the LPS (in arithmetic coding).

**3.1.98**

**probability interval:**

The probability of a particular sequence of binary decisions within the ordered set of all

possible sequences (in arithmetic coding).

**3.1.99**

**(probability) sub-interval:**

A portion of a probability interval allocated to either of the two possible binary

decision values (in arithmetic coding).

**3.1.100**

**procedure: **

A set of steps which accomplishes one of the tasks which comprise an encoding or decoding

process.

**3.1.101**

**process:**

See coding process.

**3.1.102**

**progressive (coding):**

One of the DCT-based processes defined in this Specification in which each scan

typically improves the quality of the reconstructed image.

**3.1.103**

**progressive DCT-based:**

The mode of operation which refers to any one of the processes defined in Annex G.

**3.1.104**

**quantization table:**

The set of 64 quantization values used to quantize the DCT coefficients.

**3.1.105**

**quantization value: **

An integer value used in the quantization procedure.

**3.1.106**

**quantize:**

The act of performing the quantization procedure for a DCT coefficient.

**3.1.107**

**reference (reconstructed) component:**

Reconstructed component data which is used in a subsequent frame of a

hierarchical encoder or decoder process (in hierarchical mode coding).

**CCITT Rec. T.81 (1992 E)**

**5**