ISO/IEC 14492:2019 情報技術—2レベル画像の不可逆/可逆コーディング | ページ 6

3.1

adaptive template pixel(s)

Special pixel(s), in a template, whose location is not fixed.

3.2

aggregation

Joining or merging of several individual symbols into a new symbol.

3.3

bi-level image

Rectangular array of bits.

3.4

bit

Binary digit, representing the value 0or1.

3.5

bitmap

Bi-level image.

3.6

buffer

Storage area used to hold a bitmap.

3.7

byte

Eight bits of data.

3.8

combination operator

Operator used to combine the prior contents of a bitmap with new values being drawn into that bitmap.

3.9

coordinate system

Numbering system for two-dimensional locations where locations are labelled by two numbers, the first one increasing from left to right and the second one increasing from top to bottom.

3.10

delta S

Difference in the S coordinates between two successive symbol instances in a non-empty strip.

3.11

delta T

Difference in the T coordinates between two successive non-empty strips.

3.12

decoding procedure

Component of a decoder that decodes a certain type of data.

3.13

decoder

Entity capable of decoding a bitstream in conformance with this Recommendation | International Standard.

3.14

dictionary

List of bitmaps.

3.14.1

pattern dictionary

List of patterns.

3.14.2

symbol dictionary

List of symbols.

3.15

export flag

Bit indicating that a symbol is on the export list of a symbol dictionary.

3.16

export list

List of the symbols in a symbol dictionary that may be used by referring to that symbol dictionary.

3.17

gray-scale image

Rectangular array of non-negative integer indices.

3.18

gray-scale pixel

Integer-valued element in a gray-scale image.

3.19

halftone grid

Rectilinear grid of locations specifying where patterns are to be drawn.

3.20

height class

Set of symbols in a symbol dictionary whose heights are all equal.

3.21

height class delta height

Difference in height between two height classes.

3.22

height class delta width

Difference in width between two symbols in a height class.

3.23

Huffman table

Collection of table lines specifying how values are encoded.

3.24

lossless coding

Method of encoding data so that the decoded data are identical to the original data.

3.25

lossy coding

Method of encoding data so that the decoded data differ, ideally only in insignificant ways, from the original data.

3.26

ordinal

Value used as a counter.

3.27

out-of-band value

Non-numeric value that may be produced in place of an integer.

3.28

pattern

Bitmap produced by a pattern dictionary decoding procedure.

3.29

pixel

Element with 0or1 as its value in a bitmap.

3.30

prefix length

Length of the Huffman code prefix in a table line.

3.31

range length

Number of additional code bits in a table line.

3.32

reference bitmap

Bitmap used as the reference plane during the refinement region decoding procedure.

3.33

referred-to segment

Other segment required in order to decode the current segment.

3.34

region

Bitmap produced by a region decoding procedure.

3.35

segment

Segment header and its segment data.

3.36

strip

Full-width or full-height portion of the coordinate system of a text region.

3.37

strip size

Extent in pixels of the non-full dimension of a strip.

3.38

symbol

Bitmap produced by a symbol dictionary decoding procedure.

3.39

symbol ID

Integer used to identify a symbol or to index into an array of symbols to retrieve the symbol.

3.40

symbol instance

Symbol drawn, possibly with refinement, at a particular location in a text region.

3.41

symbol instance refinement delta height

Difference in height between a symbol instance’s reference bitmap and the bitmap produced by the generic refinement region decoding procedure.

3.42

symbol instance refinement delta width

Difference in width between a symbol instance’s reference bitmap and the bitmap produced by the generic refinement region decoding procedure.

3.43

symbol instance refinement delta X

Difference between the X coordinates of the top left corners of a symbol instance’s reference bitmap and the bitmap produced by the generic refinement region decoding procedure.

3.44

symbol instance refinement delta Y

Difference between the Y coordinates of the top left corners of a symbol instance’s reference bitmap and the bitmap produced by the generic refinement region decoding procedure.

3.45

table line

Specification of the encoding of a single value or a range of values as a Huffman code prefix followed by a fixed number of additional code bits.

3.46

typical prediction

Method of signalling that an entire row of a generic region is identical to the preceding row.

3.47

value

Integer or out-of-band indicator that is decoded.