ISO/IEC 10918-1 : 1993(E)
Ta
j
AC entropy table destination selector for jth component in scan
Tb
arithmetic conditioning table destination identifier
Tc
Huffman coding or arithmetic coding table class
Td
j
DC entropy table destination selector for jth component in scan
TEM
temporary marker
Th
Huffman table destination identifier in DHT segment
Tq
quantization table destination identifier in DQT segment
Tq
i
quantization table destination selector for ith component in frame
U
DC and lossless coding conditioning upper bound parameter
V
symbol or value being either encoded or decoded
V
i
vertical sampling factor for ith component
V
i,j
jth value for length i in HUFFVAL
V
max
largest vertical sampling factor
V
t
temporary variable
VALPTR
list of indices for first value in HUFFVAL for each code length
V1
symbol value
V2
symbol value
x
i
number of columns in ith component
X
number of samples per line in component with largest horizontal dimension
X
i
ith statistics bin for coding magnitude category decision
X1, X2, X3, ... , X15
designation of context-indices for coding of magnitude categories in the arithmetic coding
models
XHUFCO
extended Huffman code table
XHUFSI
table of sizes of extended Huffman codes
X'values'
values within the quotes are hexadecimal
y
i
number of lines in ith component
Y
number of lines in component with largest vertical dimension
ZRL
value in HUFFVAL assigned to run of 16 zero coefficients
ZZ(K)
Kth element in zig-zag sequence of quantized DCT coefficients
ZZ(0)
quantized DC coefficient in zig-zag sequence order
4
General
The purpose of this clause is to give an informative overview of the elements specified in this Specification. Another
purpose is to introduce many of the terms which are defined in clause 3. These terms are printed in italics upon first usage
in this clause.
12
CCITT Rec. T.81 (1992 E)