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

Da

in DC coding, the DC difference coded for the previous block from the same component;

in lossless coding, the difference coded for the sample immediately to the left

DAC

define-arithmetic-coding-conditioning marker

Db

the difference coded for the sample immediately above

DC

DC DCT coefficient

DC

i

DC coefficient for *i*th block in component

DC

k

*k*th DC value used in prediction of AC coefficients

DHP

define hierarchical progression marker

DHT

define-Huffman-tables marker

DIFF

difference between quantized DC and prediction

DNL

define-number-of-lines marker

DQT

define-quantization-tables marker

DRI

define restart interval marker

E

exponent in magnitude category upper bound

EC

event counter

ECS

entropy-coded segment

ECS

i

*i*th entropy-coded segment

Eh

horizontal expansion parameter in EXP segment

EHUFCO

Huffman code table for encoder

EHUFSI

encoder table of Huffman code sizes

EOB

end-of-block for sequential; end-of-band for progressive

EOBn

run length category for EOB runs

EOBx

position of EOB in previous successive approximation scan

EOB0, EOB1, ..., EOB14

run length categories for EOB runs

EOI

end-of-image marker

Ev

vertical expansion parameter in EXP segment

EXP

expand reference components marker

FREQ(V)

frequency of occurrence of symbol V

H

i

horizontal sampling factor for *i*th component

H

max

largest horizontal sampling factor

HUFFCODE

list of Huffman codes corresponding to lengths in HUFFSIZE

HUFFSIZE

list of code lengths

HUFFVAL

list of values assigned to each Huffman code

i

subscript index

I

integer variable

Index(S)

index to probability estimation state machine table for context index S

j

subscript index

J

integer variable

**8**

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