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

**3.2**

**Symbols**

The symbols used in this Specification are listed below.

A

probability interval

AC

AC DCT coefficient

AC

ji

AC coefficient predicted from DC values

Ah

successive approximation bit position, high

Al

successive approximation bit position, low

Ap

i

*i*th 8-bit parameter in APP

n

segment

APP

n

marker reserved for application segments

B

current byte in compressed data

B2

next byte in compressed data when B

=

X'FF'

BE

counter for buffered correction bits for Huffman coding in the successive approximation

process

BITS

16-byte list containing number of Huffman codes of each length

BP

pointer to compressed data

BPST

pointer to byte before start of entropy-coded segment

BR

counter for buffered correction bits for Huffman coding in the successive approximation

process

Bx

byte modified by a carry-over

C

value of bit stream in code register

C

i

component identifier for frame

C

u

horizontal frequency dependent scaling factor in DCT

C

v

vertical frequency dependent scaling factor in DCT

CE

conditional exchange

C-low

low order 16 bits of the arithmetic decoder code register

Cm

i

*i*th 8-bit parameter in COM segment

CNT

bit counter in NEXTBYTE procedure

CODE

Huffman code value

CODESIZE(V)

code size for symbol V

COM

comment marker

Cs

conditioning table value

Cs

i

component identifier for scan

CT

renormalization shift counter

Cx

high order 16 bits of arithmetic decoder code register

CX

conditional exchange

d

ji

data unit from horizontal position i, vertical position j

d

ji

k

d

ji

for component k

D

decision decoded

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

**7**