ISO/IEC TR 19566-2:2016 情報技術— JPEGシステム—パート2：輸送メカニズムとパッケージング | ページ 6

3.1.1

bit stream

partially encoded or decoded sequence of bits comprising an entropy-coded segment

3.1.2

box

structured collection of data describing the image or the image decoding process

Note 1 to entry: See ISO/IEC 19566-1 for the definition of boxes.

3.1.3

box-based file format

file format whose composing elements are well-defined, hierarchically structured boxes

3.1.4

byte

group of 8 bits

3.1.5

coder

embodiment of a coding process

3.1.6

codestream

sequence of bits, representing a compressed image and associated metadata

3.1.7

coding

e ncoding or decoding

3.1.8

coding model

procedure (3.1.27) used to convert input data into symbols to be coded

3.1.9

(coding) process

general term for referring to an encoding process (3.1.16) , a decoding process (3.1.14) or both.

3.1.10

compression

reduction in the number of bits used to represent source image data

3.1.11

component

two-dimensional array of samples (3.1.28) having the same designation in the output or display device

Note 1 to entry: An image typically consists of several components, e.g. red, green and blue.

3.1.12

continuous-tone image

image whose components (3.1.11) have more than 1 bit per sample (3.1.28)

3.1.13

decoder

embodiment of a decoding process (3.1.14)

3.1.14

decoding process

process which takes as its input compressed image data and outputs a continuous-tone image (3.1.12)

3.1.15

encoder

embodiment of an encoding process (3.1.16)

3.1.16

encoding process

process which takes as its input a continuous-tone image (3.1.12) and outputs compressed image data

3.1.17

entropy-coded (data) segment

independently decodable sequence of entropy-encoded bytes of compressed image data

3.1.18

entropy decoder

embodiment of an entropy decoding (3.1.19) procedure

3.1.19

entropy decoding

lossless procedure which recovers the sequence of symbols from the sequence of bits produced by the entropy encoder (3.1.20)

3.1.20

entropy encoder

embodiment of an entropy encoding (3.1.21) procedure

3.1.21

entropy encoding

lossless procedure which converts a sequence of input symbols into a sequence of bits such that the average number of bits per symbol approaches the entropy of the input symbols

3.1.22

Joint Photographic Experts Group

JPEG

informal name of the committee that created this document

Note 1 to entry: The “joint” comes from the ITU-T and ISO/IEC collaboration.

3.1.23

JPEG standards

collection of ISO/IEC/ITU standards developed by the Joint Photographic Experts Group (3.1.22) for still imaging application as listed in Clause 2

3.1.24

JPEG systems

common elements of a system layer for JPEG standards (3.1.23)

3.1.25

metadata

additional data associated with the image data beyond the image data

3.1.26

pixel

collection of sample (3.1.28) values in the spatial image domain having all the same sample coordinates

3.1.27

procedure

set of steps which accomplishes one of the tasks which comprise an encoding (3.1.16) or decoding process (3.1.14)

3.1.28

sample

one element in the two-dimensional image array which comprises a component (3.1.11)

3.1.29

superbox

box (3.1.2) that itself contains a contiguous sequence of boxes, and only a contiguous sequence of boxes