ISO 10758:1994

Graphic technology - Prepress digital data exchange - Online transfer from electronic prepress systems to colour hardcopy devices

Specifies the mechanical, electrical, protocol and data format characteristics to permit online transfer of digital colour proof data between colour electronic prepress systems (CEPS) and direct digital colour proofing (DDCP) systems. The transfer protocol neither requires nor provides a mechanism to guarantee a sustained data rate. The mechanical and electrical characteristics and the transport level protocol make use of the small computer system interface (SCSI).

Technologie graphique — Échange de données digitales de préimpression — Transfert en ligne en provenance de systèmes de préimpression électronique vers des copies papier couleur

General Information

• Status: Withdrawn
• Publication Date: 22-Jun-1994
• Withdrawal Date: 22-Jun-1994
• ICS: 35.240.30 - IT applications in information, documentation and publishing
• ICS: 37.100.99 - Other standards related to graphic technology
• Technical Committee: ISO/TC 130 - Graphic technology
• Drafting Committee: ISO/TC 130/WG 2 - Prepress data exchange
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 01-Feb-2005
• Completion Date: 13-Dec-2025

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD
First edition
1994-07-01
Graphit technology - Prepress digital
Online transfer from
data exchange -
electronie prepress Systems to colour
hardcopy devices
Technologie graphique - Echange de donnbes digitales de
- Transfert en ligne en provenance de systemes de
preimpression
preimpression 6lectronique Vers des copies papier couleur
Reference number
Contents
Page
..............................................................................................
1 Scope
.............................................................................
2 Conformance
................................................................
3 Normative references
.................................................................................
4 Definitions
.......................................................
5 Symbols and abbreviations
................................................................
6 General requirements
.............................
7 Application level protocol for proof transfer
...................................................
7.1 Application level commands
..............................................................
7.2 Command sequence
......................
8 Application level data formats for proof transfer
.........................................................................
81 . Job descriptor
..............................................................
82 . Separation descriptor
............................................................
. Image set descriptor
.............................................
84 . Contone picture file descriptor
..........................................................
85 . Line art file descriptor
..............................................
86 . Vendor-specific file descriptor
...............................................
87 . Set device feature descriptor
.............................................................
88 * Job Status response
........................................................
89 . Device Status response
,,.,.,.,.,.,. 18
8.10 Device capability response
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.11 Current feature response
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .~.
8.12 Error response
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9 SCSI as the transfer mechanism
..,...~...................,.,.....~,............~........
9.1 Physical characteristics
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2 Logical characteristics
0 ISO 1994
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronie or mechanical, including photocopying and
microfilm, without Permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-l 211 Geneve 20 l Switzerland
Printed in Switzerland
ii
43 ISO ISO 10758:1994(E)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.3 Supported SCSI commands
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
9.4 Supported SCSI messages
9.5 Transport level protocol for proof transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
10 SCSI commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
10.1 SEND command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
10.2 RECEIVE command . . . . . . . . . . . . . . . . . . . .*.*.*. 26
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
10.3 REQUEST SENSE command
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
10.4 INQUIRY command
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
10.5 MODE SELECT command
10.6 MODE SENSE command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

0 ISO
Foreword
ISO (the International Organization for Standardization) is a worldwide
federation of national Standards bodies (ISO member bodies). The work
of preparing International Standards is normally carried out through ISO
technical committees. Esch member body interested in a subject for
which a technical committee has been established has the right to be
represented on that committee. International organizations, governmental
and non-governmental, in liaison with ISO, also take patt in the work. ISO
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard ISO 10758 was prepared by the American National
Standards Institute (as ANSI IT8.4-1989) and was adopted, under a special
“fast-track procedure ”, by Technical Committee ISO/TC 130, Graphit
technology, in parallel with its approval by the ISO member bodies.

0 ISO
Introduction
The technical content of this International Standard is identical to that of
American National Standard IT8.4-1989. The ANSI document was circu-
lated for ISO approval as a fast track document at the request of the 1989
plenary meeting of lSO/TC130 and subsequent to its approval was re-
structured to be in accordance with part 3 of the lSO/IEC Directives. The
IT8 document itself resulted from the joint efforts of an international in-
dustry group that included participants representing all of the major pre-
press vendors in the world. This group, initially identified as the DDES
(Digital Data Exchange Specification) Committee, later became the foun-
ders of the ANSI IT8 (Image Technology) accredited Standards committee
which is responsible for electronie data exchange Standards in graphic arts
prepress.
The data formats are modelled on ISO 10755 and ISO 10756. The trans-
port definition is implemented via ISO 9316.
This International Standard is organized to separate the data format and
transfer protocol used at the application Ievel from that used at the trans-
port level. A primary reason for this distinction is the desire to ease the
adaptation of this International Standard to transport mechanisms other
than SCSI.
Clause 4 includes definitions. Clauses 7 and 8 describe the application
level protocol for proof transfer and the data format at the application level.
These clauses will remain valid for future CEPS to DDCP connections that
might use other transport media.
Clause 9 describes the SCSI transport medium as it is used for CEPS to
DDCP communication in this International Standard, and clause 10 de-
scribes each of the SCSI commands as they are used to implement this
International Standard.
V
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INTERNATIONAL STANDARD 0 ISO ISO 10758:1994(E)
- Prepress digital data
Graphit technology
- Online transfer from electronie prepress
exchange
Systems to colour hardcopy devices
1 Scope
This International Standard specifies the mechanical, electrical, protocol and data format characteristics to permit
online transfer of digital colour proof data between colour Electronie Prepress Systems (CEPS) and Direct Digital
Colour Proofing (DDCP) Systems. The transfer protocol neither requires nor provides a mechanism to guarantee
a sustained data rate. The mechanical and electrical characteristics and the transport level protocol make use of
the Small Computer System Interface (SCSI).
This International Standard takes precedence if a conflict exists with respect to the Standards indicated in
clause 3.
2 Conformance
A DDES implementation shall be in conformance with this International Standard if it meets the requirements of
clauses 6 through IO.
3 Normative references
The following Standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the editions indicated were valid. All Standards are subject to
revision, and Parties to agreements based on this International Standard are encouraged to investigate the possi-
bility of applying the most recent editions of the Standards indicated below. Members of ISO and IEC maintain
registers of currently valid International Standards.
ISO/1 EC 646: 1991 I Information technology - ISO 7-bit coded Character set for information interchange.
ISO 93 16: 1989, Information processing Systems - Small Computer System Interface (SCSI).
ISO 10755:1992, Graphit technology - Prepress digital data exchange - Colour picture data on magnetic tape.
ISO 10756: 1994, Graphit technology - Prepress digital data exchange - Colour line art data on magnetic tape.
4 Definitions
For the purposes of this International Standard, the following definitions apply.
4.1 Digital Data Exchange Specification (DDES): A method of sharing digitally encoded information between
cooperating Systems.
4.2 decimal Point notation: The expression of a decimal number in a numeric field as a string of numeric
characters (ISO/IEC 646 positions 3/0 to 3/9), with optional decimal Point (ISO/lEC 646 Position 2/14 - full stop).
43 . contone (colour picture) data: A rectangular array of picture elements ( “Pixels ”).
NOTE 1
A Pixel is represented by a set of values corresponding to its colour components, and for a four-colour picture
consists of four eight-bit bytes, representing cyan ( “C ”), magenta ( “M ”), yellow ( “Y ”) and black ( “K ”) process colours.
4.4 line art data: A rectangular array of picture elements ( “pixels ”), each of which holds one of a limited number
of colours. The colours may be defined in a colour Palette table, which specifies the values of the colour Separation
components for each entry in the Palette.
NOTE 2 Line art data are generally characterized by having contiguous areas of many Pixels of the same Palette entry, and
not simulating a greater range of colours by “dithering” or “error diffusion” techniques. The spatial information is therefore
amenable to run length encoding techniques, which may reduce file size and allow for faster processing.
45 . vendor-specific data: Data sent at the discretion of the vendor.
4.6 proof: A Simulation or prototype of a graphic arts printed image.
4.7 Direct Digital Colour Proofer (DDCP): An output device capable of producing a proof directly from digital
data.
4.8 image set: A logical grouping of data (contone picture data, line art data, vendor-specific data) used to create
a rectangular area of a proof.
5 Symbols and abbreviations
The following Symbols and abbreviations are used in this International Standard:
.
BP . Byte Position within a label. For ease of use with ISO 9316, byte positions Start with 0.
L: Length of field in number of byte positions.
SPACE or ‘6: The Character coded in Position 2/0 of ISO/IEC 646.
ZERO: The Character coded in Position 3/0 of ISO/IEC 646.
.
h . Hexadecimal numbers are identified by the digits 0 to 9 and the letters A to F followed by the lower
case “h” (e.g. 3F6Ah).
6 General requirements
image Sets. Esch image set shall
A proof shall be a Single sheet of 0 utput medium and shall contain one or more
cover a rectangula r area with s ides parall el to the edg es of the media. No two image sets shall overlap.
Esch image set shall contain at least one of the following data files: contone picture data file, line art data file or
a vendor specific data file. No more than one of each type shall be included in an image set. When both a line art
file and a picture file are present within an image set, the line art file shall take precedence (i.e. the transparency
or Opacity of the line art data wil determine the visibility of the underlying picture data).
All files within an image set shal have identical placement, orientation, length of line and breadth of area (i.e. will
overlay exactly).
Data transport between the CEPS and DDCP shall utilize ISO 9316 as defined within this International Standard.
The application layer shall communicate with the transport layer via application level commands and data descrip-
tors shall be used to transfer relevant Information between the CEPS and DDCP.
43 ISO
7 Application level protocol for proof transfer
The application layer communicates with the transport layer via application Ievel commands. These commands
convey data attribute information by means of descriptors.
Twelve types of data descriptors are specified for proof transfer; seven are used to describe the information sent
from the CEPS to the DDCP and five are used to describe the information sent from the DDCP to the CEPS.
The descriptors for transfer to the DDCP are Job Descriptor, Separation Descriptor, Image Set Descriptor, Contone
Picture File Descriptor, Line Art File Descriptor, Vendor Specific File Descriptor and Set Device Feature Descriptor.
The descriptors for transfer from the DDCP are Job Status Response, Device Status Response, Device Capability
Response, Current Feature Response and Error Response.
7.1 Application level commands
The following commands are specified for communication with the transport level: SEND JOB, STOP JOB, GET
JOB STATUS, GET DEVICE STATUS, GET DEVICE CAPABILITY, SET DEVICE FEATURE, GET CURRENT FEATURE
and REPORT STATUS.
The first five shall always be used and must be implemented. The last three shal I be used to support the optional
“spontaneous Status report” feature.
is GOOD, processing continues.
The responses to commands shall either be GOOD or ERROR. If the response
mation. The error response data
If the response is ERROR, the error response data structure contains error info
structure is described in 8.12.
The manner in which the transport layer implements these application Ievel commands is dependent on the par-
ticular transport medium used. A SCSI implementation is described in this International Standard.
7.1.1 SEND JOB
A job shall be started by sending the following information, in the Order described, from the CEPS to the DDCP:
- Job Descriptor (8.1);
- the first Separation Descriptor (8.2);
- other Separation descriptors;
- the first Image Set Descriptor (8.3);
- the first Contone Picture File Descriptor (8.4) and Contone Picture Data (if it exists);
- the first Line Art File Descriptor (8.5), colour table (8.5.1) and Line Art Data (if it exists);
- the first Vendor-specific File Descriptor (8.6) and Vendor Specific Data (if it exists);
- other image set descriptors, file descriptors and data.

Q ISO
EXAMPLE (Sample sequence of data transfer)
This example Shows the Order in which the descriptors and data are sent for a proof consisting of two image Sets,
the first containing both contone and line art data and the second containing contone data only.
Job Descriptor
Separation Descriptor (Sep. 1)
Separation Descriptor (Sep. 2)
Separation Descriptor (Sep. 3)
Separation Descriptor (Sep. 4)
Image Set Descriptor (Set 1)
Contone Picture File Descriptor
Contone Picture Data
Line Art File Descriptor
Colour Definition Table
Line Art Data
Image Set Descriptor (Set 2)
Contone Picture File Descriptor
Contone Picture Data
7.1.2 STOP JOB
A job that is currently transferring data to or executing on the DDCP tan be aborted by sending the STOP JOB
command. The CEPS may send this command at any time.
7.1.3 GET JOB STATUS
The Status of a job tan be determined by sending the GET JOB STATUS command. The job Status response data
is described in 8.8.
7.1.4 GET DEVICE STATUS
The Status of the DDCP device tan be determined by sending the GET DEVICE STATUS command. The device
Status response data is described in 8.9.
7.1.5 GET DEVICE CAPABILITY
The capability of the DDCP device tan be determined by sending the GET DEVICE CAPABILITY command. The
device capability response data is described in 8.10.
7.1.6 SET DEVICE FEATURE
Selectable features of the DDCP tan be set by sending the SET DEVICE FEATURE command. The Set Device
Feature Descriptor is described in 8.7.
7.1.7 GET CURRENT FEATURE
The current Status of selectable features of the DDCP tan be determined by sending the GET CURRENT FEATURE
command. The response is described in 8.11.
7.1.8 REPORT STATUS
The DDCP uses this optional command to spontaneously report the job Status. The use of this feature shall be
explicitly enabled by the CEPS (via the SET DEVICE FEATURE command) after determining that the capability is
supported (via the GET DEVICE CAPABILITY command). The job Status response data is described in 8.8.
0 ISO
7.2 Command sequence
A typical sequence of application level commands is shown in figure 1.
GET DEVICE CAPABILITY shall be used on “power-up” and optionally during Systems Operation to determine
specific characteristics and capabilities of the device.
The normal sequence for passing data to a device shall begin with a GET DEVICE STATUS command. If the ER-
ROR condition is returned, no further data will be sent until the condition has been cleared. If the Status returned
is GOOD, the SEND JOB command is sent. This process tan then repeat for all jobs that need to be sent to the
device. Optionally, the GET JOB STATUS command may be used to determine the Status of a particular job by
PROOF ID (see 8.1.2).
The STOP JOB command may be used to stop a job that is currently running. When this command is used, the
device may continue until it reaches an acceptable stopping Point.
CEPS DDCP
Get device capability (9.55) -
Device capability response (8.10)
Get device Status (9.5.4)
Send job (9.5.1)
Get job Status (9.53)
m
Job Status response (8.8)
Stop job (9.52)
Set device features (9.5.6) -
Get current features (9.5.7) -
Current features response (8.11)
- .
Error response (8.12)
Report Status (9.5.8)
Error response (8.12)
Figure 1 - Graphit arts device command sequence application level
8 Application level data formats for proof transfer
All values used in the descriptors shall be in ISO/lEC 646 representation. Numeric fields shall be right-aligned and
ZERO padded, and alphanumeric fields shall be Ieft-aligned and padded with SPACEs.
8.1 Job descriptor
There shall be one job descriptor for each job. The job descriptor shall be the first block of data sent for a job
transfer from the CEPS. The job descriptor shall be 512 bytes in length. Table 1 gives byte Position, field name,
length in bytes, and contents for the job descriptor.

Table 1 - Job descriptor
job descriptor identifier “JOBPRF”
compliance level
originating vendor name
originating site name
I,-,-” , l,,,, 11 , ,IV”
output device type
number of proofs requested
vertical scaling factor (decimal Point notation)
number of Separations
colour sequence
value for 100 % dot
format of contone data
format of line art data
number of image sets
reserved for DDES use
8.1 .l Compliance level
Compliance level specifies which Version of this International Standard is used by the job. A value of “0” means
no compliance is specified; a value of "1" means compliance with this edition of this International Standard.
8.1.2 Proof ID
Proof ID shall be a unique identifier assigned to each proof and is the Primat-y reference to the proof. The CEPS
is responsible for ensuring the uniqueness of this identifier in a multi-unit environment.
8.1.3 Job name
Job name shall be a string identifier associated with some logical collection of proofs.
8.1.4 Originating equipment vendor name and site name
Originating equipment vendor name and site name shall be provided for convenience.

0 ISO
8.1.5 Job type flag
Job type flag shall specify “N“ for normal, “T“ for test, and “V“ for vendor-specific jobs. Zero shall be valid for
“number of Separations“ and “number of image Sets“ only if the “job type flag“ is not ‘IN “. For test pictures the
DDCP may print the user data and include DDCP vendor defined test indicators.
8.1.6 Output device type
Output device type shall identify the type of proofing device. The only value currently defined is “H “; it means that
data to be halftoned is provided to the proofing device, and hence, the Separation Descriptor information is
meaningful. All other alphabetic characters are reserved for ISO use.
8.1.7 Number of proofs
The number of proofs shall be the number of copies to be printed.
8.1.8 Paper name and ink set name
Spate shall be provided for the naming of the Paper and ink set to be used. Valid names will be provided by the
DDCP vendor.
8.1.9 Scaling factors
The vertical and horizontal scaling factors specify the desired scaling of the output image size as a percentage of
the provided image size. Esch field shall be 6 bytes in length and will range from 001,OO to 999,00 with resolution
of 0 ‘01. The value of 100,OO is the default value and its occurrence means that no resizing shall be required in that
direction.
8.1.10 File disposition
File disposition will determine what to do with the data after it has been proofed. The default value shall be zero
meaning that the data on the DDCP may be deleted; a value of one means that the data shall be saved. Use and
disposition of saved data shall be a DDCP responsibility.
8.1.11 Number of Separations
The number of Separations shall be the number of individual colour Separations. Valid entries in “number of colour
Separations “, BP 233-234, are “01“ for one colour to “16“ for sixteen colours. The value “00“ is valid if the job
type flag is not “ N “; it means there are no Separation Descriptors.
8.1.12 Colour sequence
The sequence of colours (up to 16 colours in a variety of sequences) shall be defined in BP 235-250. Valid entries
in the “sequence of colour“ field are, in any sequence:
“~“ ‘1 M ‘I “C ‘I ‘1 Kl‘
- yellow, magenta, cyan and black inks.
II R ff 11 G ‘1 II B 1‘
- red, green, and blue light intensity.
- user definable colours or Separations such as
“ 1 “ to “9“
pink, varnish, etc.
‘1 1‘
Q - no colour attributes implied.
Colour descriptors shall be contiguous, left-aligned and SPACE padded.
8.1.13 Colour values
The scaling of the colour values contained in the data shall be linear with respect to printing dot percentage. The
bytes shall be unsigned and any values from 0 to 255 may be found. The relationship between byte values and
colour values (Step size, direction of slope, and intercept) shall be at the discretion of the originator of the file, but
shall be identical for all colour Separations in one file. lt shall be specified by expressing the byte values corre-
sponding to 0 % dot and 100 % dot as a string of numeric characters (ISO/IEC 646 positions 3/0 to 3/9) in
BP 251-254 and BP 255-258 respectively.
Figure 2 Shows further the scaling of colour values for the case where 0 % dot is the value 20 and 100 % dot is
the value 220.
100 AO 255
Value
Figure 2 - Example of scaling of colour values
8.1.14 Format of contone data
There are three formats for interleaving the picture data: Pixel interleaving, line interleaving and colour interleaving.
BP 259-260 shall contain one of the following values:
11 II
- Pixel interleaving;
II II
01 - line interleaving;
II II
02 - colour interleaving.
8.1 .14.1 Pixel interleaving
A row of alternating colour Pixels (Sets of rt colours of yt Separations) forms a line of the picture, and a sequence
of these lines forms the breadth of the picture.
To ensure compatibility with machines using 16-bit words there shall be an even number of bytes per line written.
Therefore, if the number of colour Separations and the number of pixels/line are both odd, there shall be one re-
dundant byte at the end of each line.

0 ISO
8.1 .14.2 Line interleaving
One line of a colour is followed by that line of the next colour (n lines of IZ colour Separations).
To ensure compatibility with machines using 16-bit words there shall be an even number of bytes per line written.
Therefore, if the number of pixels/line is odd, there shall be one redundant byte at the end of each line.
8.1 .14.3 Colour interleaving
All lines of one colour are followed by all lines of the next colour (n images of IZ colour Separations).
To ensure compatibility with machines using 16-bit words there shall be an even number of bytes per line written.
Therefore, if the number of pixels/line is edd, there shall be one redundant byte at the end of each line.
8.1.15 Format of line art data
BP 261-262 shall contain the values “30” to indicate coloured line art data.
8.1.16 Number of image sets
Number of image sets shall be the number of nonoverlapping rectangular areas to be placed on the output Page.
BP 263-264, shall be “01” to “99 ”. The value “00” is valid if the job type
Valid entries in “number of image Sets ”,
flag is not ” N I ’; it means there are no Image Set Descriptors.
8.2 Separation descriptor
There is a Separation descriptor for each Separation specified in the job descriptor. The Separation descriptor shall
be 128 bytes in length. Table 2 gives byte Position, field name, length in bytes, and content for the Separation
descriptor.
Table 2 - Separation descriptor
BP Field name Ld Content
6 “SEPb”
00-03 Separation descriptor identifier
2 “01 ” - “16”
04-05 Separation number
dot gain table reference identifier 2
06-07
08-11 solid area density 4
1 “1” or “M”
12 units of Screen ruling
Il II
1 = lines/inch
l’ M ” = lines/millimetre
Screen ruling (decimal Point notation) 6
13-18
Screen angle (decimal Point notation) 5
19-23
24-43 dot shape 20
44-45 trap table reference identifier 2
46-83 reserved for DDES use 38
84-127 reserved for vendor use 44
8.2.1 Dot gain table reference identifier
The dot gain table reference identifier shall be passed to the DDCP from the CEPS and provides a reference to the
particular dot gain table, contained in the DDCP, to be used for the Separation.

Q ISO
8.2.2 Solid area density
Solid area density shall be the densitometric value of a solid patch of the particular ink. The value fange is 0,OO to
5 ’00.
8.2.3 Screen ruling
Screen ruling shall be the number of lines (or dots) per unit (inch or millimetres) on a half tone Screen. The value
fange shall be 0 ’00 to 500,OO with resolution of 0,Ol.
8.2.4 Screen angle
Screen angle (in degrees) shall be the angle at which the half tone screens are intended to be placed with respect
to a common reference line (the horizontal axis of the image set) measured counter clockwise. The value range
shall be 0 ’0 to 360 ’0 with a resolution of Oll.
8.2.5 Dot shape
Dot shape shall be a name description of the shape of the dot. Valid names will be provided by the DDCP vendor.
8.2.6 Trap table reference identifier
The trap table referenceidentifier shall be passed to the DDCP from the CEPS and provides a reference to the
particular trap table, contained in the DDCP, to be used for the Separation.
NOTE 3 Trap is a measure of the efficiency of transfer of one ink printed on top of another ink compared to that same ink
printed on a plain Substrate.
8.3 Image set descriptor
There shall be an image set descriptor for each image set. The image set descriptor shall be 128 bytes long.
Table3 gives byte position, field name, length in bytes and content for an image set descriptor.
Table 3 - Image set descriptor
Content
Field name
BP
4 l’ I MGV’
00-03 image set descriptor identifier
2 “01 ” - l’99”
04-05 image set number
06-15 relative horizontal placement of picture (decimal Point
notation in millimetres)
IO
16-25 relative vertical placement of picture (decimal Point no-
tation in millimetres)
26-27 orientation
28-37 length of line (decimal Point notation in millimetres)
IO
38-47 breadth of area (decimal Point notation in millimetres)
1 “Y” or “ N ”
48 CPF exists
1 ‘IY” or ” N ”
49 LAF exists
1 “Y” or “N ”
50 VSF exists
51-77 reserved for DDES use
vendor-specific information 50
78-127
0 ISO ISO 10758:1994(E)
8.3.1 Horizontal placement
Relative horizontal placement shall be the horizontal placement of the top-left corner of the image set relative to
the top-left corner of the proof image area.
8.3.2 Vertical placement
Relative vertical placement shall be the vertical placement of the top-left corner of the image set relative to the
top-left corner of the proof image area.
8.3.3 Orientation, length and breadth
The definition of length and breadth of a picture shall be specified in BP 28-47 and the relationship of these par-
ameters to orientation is depicted in figure3. The Position and direction of the arrow indicates the sequence of the
first row of data from the file. Length refers to the length of the first line of data in the picture file, while breadth
refers to distance over which the lines are spread.
Value: 00 01
c--------------------- ------------- -w--m
-----------v--m
!
I
I
I
f
I
I
I
I
I
R
I ---------------
I
m I
R
I I
I
----------------------
a--------------------w. J
Relationship between first line of data, image orientation and orientation code
Figure 3 -
The orientation shall be specified as follows (see figure3):
‘1 1’
= load from top left, horizontally
II ‘1
01 = load from top left, vertically
II ‘1
02 = load from bottom left, horizontally
II ‘1
03 = load from bottom left, vertically
8.3.4 Existente fields
BP 48-50 shall indicate whether or not the contone picture, line art or vendor specific files are part of this image
set.
8.4 Contone picture file descriptor
A contone picture file descriptor shall precede a contone picture file. lt shall be 128 bytes in length. Table4 gives
byte position, field name, length in bytes and content for the contone picture file descriptor.
Table 4
- Contone picture file descriptor
corresponding image set number
number of Pixels per line
number of lines (breadth)
units of resolution of linel)
= pixels/millimetre
units of resolution of breadthl)
resolution of linel) (decimal Point notation)
resolution of breadthl) (decimal Point notation)
reserved for DDES use
vendor-specific information
1) This item is optional.
BP 18-31 shall specify the resolution, in both the length and breadth directions. The use of these fields is optional.
8.5 Line art file descriptor
The line art file descriptor shall precede a line art file (colour tables and run length encoded data, as specified in
ISO 10756). lt shall be 128 bytes in length. Table 5 gives byte Position, field name, length in bytes and content for
the line art file descriptor.
Table 5 - Line art file descriptor
L Content
BP Field name
4 ” LAFb ”
line art file descriptor identifier
00-03
2 “01 ” - "99"
04-05 corresponding image set number
06-11 number of Pixels per line
12-17 number of lines
18 units of resolution of linel)
1’ II
1 = pixelslinch
” M ” = pixels/millimetre
units of resolution of breadthl)
II II
1 = lines/inch
” M ” = lines/millimetre
20-25 resolution of linel) (decimal Point notation)
resolution of breadthl) (decimal Point notation)
26-31
32-35 last valid colour number used
4 "0008"
36-39 number of bits for colour number
4 "0008"
40-43 number of bits for short run
“00” or “,6”
44-47 number of bits for extended run
48-77 reserved for DDES use
78-127 vendor-specific information
1) This item is optional.
BP 18-31 shall specify the resolution, in both the length and breadth directions. The use of these fields is optional.
8.5.1 Colour description
8.5.1 .l Colour table
The colour table shall establish the connection between the colour numbers in the data entries and the colour
values assigned to those colour numbers. lt shall consist of from two to 256 twenty-byte entries as shown in
ta ble 6.
Table 6 - Colour table format
v
Description of use
Table entry Colour number
L
1 reserved for transparency
2 1
. .
. .
discrete colour descriptions
. .
256 255
I
Colour number zero shall be a transparent colour. For colour number Zero, or any colour identified as transparent,
the values indicated in the colour table shall be reserved for vendor (System) use only and treated as nonprinting
colours.
Esch colour number must be in proper sequence from 1 to 255, and in its proper location in the colour table, e.g.
colour number 1 is the second entry, colour number 10 is the eleventh entry, etc. Entries for unused colour
numbers shall be filled with Zeros in bytes 0-19.
Esch 20-byte entry in the colour table consists of a sequence of binary numbers, organized as shown in table7.
Table 7 - Colour table entry format
BYTE Description of use
reserved for ISO use
colour number
Transparency indicator for 1 to 16 Separations
Colour values in the sequence defined by BP 235-250
of the job descriptor
Colour number is used to link run lengths in the data with specific colour values. The colour number shall be a
binary value from 0 to 255, representing colour numbers 0 to 255.
Bits 0 to 15 of bytes 2 and 3 combined shall be used as a transparency indicator to signify which Separations, if
any, are transparent. A binary “1” indicates that the flagged Separations are transparent.
NOTE 4 The following Shows the use of transparency indicators.
Byte Two Three
Bit 15 8 7 0
nontransparency colour
0000 0000 0000 0000 signifies
0000 0000 0001
signifies that one or more of the defined
Separations will be transparent
. . . .
1111 1111 1111 1110
1111 1111 1111 1111 signifies that all Separations are transparent
8.5.1.2 Transparent colours
A transparent colour shall be used to distinguish a clear run, where no colour is present and the underlying image
(if any) is allowed to show through, from the colour “white ”, which signifies no underlying image shall Show
through but only the underlying Substrate (Paper). Transparency tan be used as a run length offset indicator to
allow movement within an image from the edge of an image rectangle to the Start of image, or from one defined
printing colour to another defined printing colour within an image without overlaying whatever may be underneath.
Colour number zero and the value FFFFh in bytes 2 and 3 of a colour table entry shall be reserved to signify a fully
transparent colour. The value FFFFh shall be loaded in colour number Zero. Any colour values in bytes 4 to 19 of
fully transparent colour number entries shall be reserved for vendor use and treated as nonprinting colours. All
fields should be padded with binar-y Zeros to fill fields as required.
0 ISO
The values 0001 h to FFFEh in bytes 2 and 3 of the colour table entry shall signify that one or more of the defined
Separations are transparent. The bit mask defined by the value specified defines which Separations are transparent
according to the colour sequence specified in BP 237-252 of the job descriptor such that the least significant bit
of the defined bit mask corresponds to the first Separation defined by the colour sequence.
NOTE 5 For example the value FFFI h (bit mask: 1111 1111 1111 0001) signifies that “Y” is transparent where the colour
sequence defined is “YMCK ”. The value FFF6h (bit mask: 1111 1111 1111 0110) signifies the second and third Separations
are transparent ( “M” and “Y” where the colour sequence defined is “CMYK ”).
The value OOOOh indicates that all Separations are nontransparent colou rs. Transpare ncy ind icato rs for any unused
Separations shall be set to binar-y one.
8.5.2 Run length description
8.5.2.1 Run length encoding
There shall be two formats for encoding run lengths; a short form (16 bits lang) for encoding run lengths up to 255
Pixels long, and a long form (32 bits lang) for encoding run lengths up to 65 535 Pixels long. Both forms may be
freely mixed within a file since the long form is encoded as a special case of the short form. There shall be no
Obligation to write both forms, since long runs tan be encoded with repetitions of the short form.
The short form shall consist of a two-byte entry. The first eight bits shall be a binary number representing the
colour number in the colour table with a value from 0 to 255, and the second eight bits shall be a binary number
representing the run length from 1 to 255.
The long form shall consist of a four-byte entry. The first eight bits shall be a binary number representing the colour
number in the colour table with a value from 0 to 255, and the second eight bits shall equal zero to signify the long
form. The next 16 bits shall be a binary number representing the run length from 1 to 65 535. If the long form is
used to encode a run length of less than 256, byte 2 shall be binary Zero, and the run length shall be in byte 3.
NOTE 6 The short and long forms of the run length encoding format are illustrated as follows:
0 1 2 and 3
Byte
not applicable
Short form colour run length
(run length)
Long form colour 0
Esch line of data (whose orientation to the image is defined in the image set descriptor) shall be initiated by two
zero bytes and terminated by two zero bytes.
If the number of Pixels in an encoded line does not equal the declared number of Pixels per line of the image, or
the number of encoded lines of data does not equal the number of lines in the image, an error exists and continued
processing shall be at the discretion of the processing System.
Run lengths of zero shall be specifically excluded in both the long form and the short form since this would conflict
with other indicators.
8.5.2.2 Line repeat code
Within the data encoding structure a four byte binary line repeat code may be used to signify that the previous line
shall be repeated the number of times specified by the first byte of the line repeat code (up to 255 times). The
second, third and fourth bytes shall be Zero, to indicate that this is a line repeat Code. Esch line repeat code shall
begin and end with a line terminator, so the line repeat code shall always be a line by itself. For image runs that
exceed 255 the line repeat code may be repeated as often as necessary until the cumulative total of line repeat
Codes minus one (for the original line) equals the number of lines in the repeated section of the image.
EXAMPLE
Line begin Line end
Data within the line code
code
Line n: 00 (encoded image data) 00
Line n + 1: 00 255 0 0 0 00
Line n + 2: 00 55 0 0 0 00
indicates that the line of data encoded by line n will occur 311 times:
once for the initial time the line is encountered (line n ), plus 255 times
for the line count indicator in line n + 1. plus 55 times for the line count
indicator in line n + 2
There shall be no Obligation to encode an image with line repeat Codes since images tan be encoded by repeating
an encoded line the required number of times.
8.6 Vendor-specific file descriptor
Where vendor-specific files are used, the number of data bytes must be a multiple of 128.
Table8 gives byte Position, field name, length in bytes and content for the vendor-specific file descriptor.
Table 8 - Vendor-specific file descriptor
BP Field name L Content
00-03 vendor-specif ic f ile descriptor identif ier 4 “VSFb ”
04-05 corresponding image set number "01 " - "99"
number of bytes of vendor specific descriptor
06-15 10
information (X bytes)
number of bytes of vendor specific data to
16-25 10
follow
26-(25+X) vendor-specific descriptor information X
(26+X)-127 pad to 128 bytes IOZ-x
NOTE -X must be a multiple of 4.
8.7 Set device feature descriptor
Table9 gives the contents of the set device feature descriptor.
SPONSTATUS is the feature which allows the DDCP to spontaneously (i.e. without explicit request from the CEPS)
send a Status response to the CEPS when a job is finished.
SPONSTATUS is the only feature currently defined. As others are defined, they shall follow sequentially in the
space reserved for DDES.
Table 9 - Set device feature descriptor
BP Field name L
Content
00-05 set device features identifier
6 “SETDEV”
06-07
number of features 2
08-17 feature name 10 “SPONSTATUS”
18 feature existente 1
“Y”
19 feature enabled 1 “Y” or ” N ”
20-187 reserved for DDES 168
188-255 vendor-specific information 68
8.8 Job Status response
Table 10 gives the contents of the job Status response.
Table 10 - Job Status response
BP Field name L Content
00-05 job Status response identifier 6 “STATUS”
06-11 proof identification 6
12-51 job name 40
52-61 proof Status 10
” COMPLETE ”
” INPROGRESS ”
” STOPPED ”
” ERRORxxxxx ”
62-64 proof number
65-112 reserved for DDES use
113-127 reserved for vendor use 15
This information is returned in response to the GET JOB STATUS command (see 9.1.3 and 6.5.3) and the REPORT
STATUS command (see 9.1.8 and 6.5.8).
8.9 Device Status response
Table 11 gives the contents of the device Status response.
Table 11 - Device Status response
BP Field name
00-05 device Status response identifier
06-25 device Status
II
” IDLE
1’
“BUSY-SEND DATA
II
“BUSY-HOLD DATA
1'
“NOT READY-ERROR
26-127 reserved for DDES use
8.10 Device capability response
Table 12 gives the contents of the device capability response.
Table 12 - Device capability response
BP Field name L Content
00-05 device capability response identifier 6 “ D EVCAP”
06 compliance level (8.1 .l) 1 I‘ 1 II
07-46 vendor identification (8.1.4) 40
47-86 product identification (8.10.1) 40
87-126 product revision level (8.10.1) 40
127 output device type (8.1.6) 1 “H “
128-133 maximum vertical scaling (8.1.9) 6
134-139 minimum vertical scaling (8.1.9) 6
140-145 maximum horizontal scaling (8.1.9) 6
146-151 minimum horizontal scaling (8.1.9) 6
152-153 maximum number of Separations (8.1 .l 1) 2
154-169 preferred colour sequence (8.10.2) 16
170 alternate sequence accepted (8.10.2) 1 “Y “ or “ N ”
171-174 preferred value for 0 % dot (8.10.3) 4
175-178 preferred value for 100 % dot (8.10.3) 4
179 alternative values accepted (8.10.3) 1 “Y “ or “ N “
180 interleave support (inclusive or) (8.10.4) 1
“1” colour
“2” line
“4” Pixel
181-182 maximum number of image sets (8.1 .16)
183-186 maximum solid density (8.2.2) 4
187-196 maximum line length in millimetres (8.3.3)
197-206
maximum page breadth in millimetres (8.3.3) 10
207-208 orientation support (inclusive or) (8.10.5) 2
“ 1 " 00
“2" 01
“4“ 02
“8" 03
209-216 buffer size in
...