ISO/IEC TS 29112:2012

Information technology - Office equipment - Test charts and methods for measuring monochrome printer resolution

ISO/IEC 29112 defines methods for the objective measurement of the print quality characteristics that contribute to the perceived resolution of reflection mode monochrome printed pages produced by digital electro-photographic printers. The measurement methods used in ISO/IEC 29112 are derived from several existing techniques for the assessment of an imaging system's resolution characteristics. Each of these measurement methods is intended for the engineering evaluation of a printing system's perceived resolution and not for purposes of advertising claims. The methods are applicable only to monochrome prints produced in reflection mode by electro-photographic printing technology. ISO/IEC 29112 is intended for monochrome printers utilizing postscript interpreters capable of accepting postscript and encapsulated postscript (EPS) jobs.

Technologies de l'information — Équipement de bureau — Diagrammes et méthodes pour mesurer la résolution des imprimantes monochrome

General Information

• Status: Withdrawn
• Publication Date: 29-Jul-2012
• Withdrawal Date: 29-Jul-2012
• ICS: 37.100.10 - Reproduction equipment
• Technical Committee: ISO/IEC JTC 1/SC 28 - Office equipment
• Drafting Committee: ISO/IEC JTC 1/SC 28 - Office equipment
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 07-Nov-2018
• Completion Date: 30-Oct-2025

Relations

• Revised: ISO/IEC 29112:2018 - Information technology - Office equipment - Test pages and methods for measuring monochrome printer resolution
• Effective Date: 05-Nov-2015

Standards Content (Sample)

TECHNICAL ISO/IEC
SPECIFICATION TS
First edition
2012-08-01
Information technology — Office
equipment — Test charts and methods
for measuring monochrome printer
resolution
Technologies de l'information — Équipement de bureau — Diagrammes
et méthodes pour mesurer la résolution des imprimantes monochrome

Reference number
©
ISO/IEC 2012
©  ISO/IEC 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
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Published in Switzerland
ii © ISO/IEC 2012 – All rights reserved

Contents Page
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Print resolution characteristics – methods for measurement and analysis . 5
4.1 Compliance requirements . 5
4.1.1 Test chart compliance . 6
4.1.2 Printing process compliance . 6
4.1.3 Scanner characteristics compliance . 6
4.1.4 Measurement method compliance . 6
4.2 Native addressability . 6
4.2.1 Method for measuring native addressability . 7
4.3 Effective addressability . 8
4.3.1 Method for measuring effective addressability . 8
4.4 Edge blurriness and edge raggedness . 9
4.4.1 Edge blurriness . 10
4.4.2 Edge raggedness . 11
4.4.3 Method for measuring edge blurriness and edge raggedness. 11
4.5 Detail carrying capability . 12
4.5.1 Printer MTF estimation from edge characteristics . 12
4.5.2 Method for measuring printer MTF from edge characteristics . 12
4.5.3 Printer MTF estimation from 1-D repeating patterns . 13
4.5.4 Method for measuring printer MTF from 1-D repeating pattern characteristics . 13
5 Test Set-up, Configurations, and Procedure . 14
5.1 Printer set-up and configuration . 14
5.2 Printer testing environment . 14
5.3 Substrate . 15
5.4 Test platform connection to the printer . 15
5.5 Test charts . 15
5.6 Sample size . 15
5.7 Printing process . 15
5.8 Set-up procedure . 15
5.9 Testing procedure for visual evaluation . 16
5.10 Testing procedure for scanner-based measurement . 16
6 Presentation of results . 16
6.1 General . 16
6.2 Required test documentation . 17
6.3 Reporting of measurement results . 17
Annex A (normative) Test charts . 19
A.1 Availability . 19
A.2 Native Addressability test chart content . 19
A.3 Effective Addressability test chart content . 19
A.4 Edge Characteristics test chart content . 20
A.5 Line Characteristics test chart content . 20
Annex B (normative) Printing process . 21
B.1 Application effects . 21
B.2 Print driver effects . 21
© ISO/IEC 2012 – All rights reserved iii

B.3 Test chart files for Postscript printers .21
B.4 Printing protocol .21
Annex C (normative) Scanner conformance .23
C.1 Required scanner characteristics .23
C.1.1 Scan characteristics .23
C.1.2 Scanner MTF characteristics .24
C.2 Method for evaluating the scanner OECF characteristic.24
C.3 Method for evaluating scanner dynamic range .24
C.4 Method for evaluating scanner usable addressability .24
C.5 Method for compensating for finite scanner MTF .24
C.6 Required scanner control application characteristics.25
Annex D (normative) Measurement method conformance .26
D.1 Effective addressability measurement method .26
D.2 Edge blurriness measurement method .27
D.3 Edge raggedness measurement method .27
D.4 Measurement method for slanted edge SFR .28
D.5 Measurement method for printer MTF evaluation from square wave elements .29
Annex E (informative) Representative reports of printer resolution assessment .30
E.1 Single configuration report .30
E.2 Multiple configuration report .31
E.3 Interpretation of results .32
Bibliography .33

iv © ISO/IEC 2012 – All rights reserved

Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are members of
ISO or IEC participate in the development of International Standards through technical committees
established by the respective organization to deal with particular fields of technical activity. ISO and IEC
technical committees collaborate in fields of mutual interest. Other international organizations, governmental
and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information
technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75 % of the national bodies casting a vote.
In other circumstances, particularly when there is an urgent market requirement for such documents, the joint
technical committee may decide to publish an ISO/IEC Technical Specification (ISO/IEC TS), which
represents an agreement between the members of the joint technical committee and is accepted for
publication if it is approved by 2/3 of the members of the committee casting a vote.
An ISO/IEC TS is reviewed after three years in order to decide whether it will be confirmed for a further three
years, revised to become an International Standard, or withdrawn. If the ISO/IEC TS is confirmed, it is
reviewed again after a further three years, at which time it must either be transformed into an International
Standard or be withdrawn.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO/IEC TS 29112 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 28, Office equipment.
© ISO/IEC 2012 – All rights reserved v

Introduction
The purpose of this Technical Specification is to provide a process for the objective measurement of print
quality characteristics that contribute to perceived printer resolution in pages printed on paper or similar
opaque materials using monochrome electro-photographic printing processes.
This Technical Specification prescribes the following:
 Definitions of the print quality characteristics that contribute to perceived resolution.
 Definitions of conformance methods to qualify a reflection scanner for use as a measuring device.
 A testing procedure based upon: a well-documented printer and printing environment setup; well-
controlled printing of specified test charts; and subsequent measurement of relevant print quality
characteristics using test pattern elements on the printed test charts.
 Definitions of methods for measuring the contributing print quality characteristics using test patterns
elements of the printed test charts, analyzing the resulting data, and deriving an assessment of printer
resolution.
 Requirements for the report of a printer resolution assessment that define the context of the
assessment and describe the results of the assessment.
Printer resolution, a quantification of the ability of a digital printing system to depict fine spatial detail, is a
perceptually complex entity with no single, simple, objective measure. Five print quality characteristics that
meaningfully contribute to resolution are described in this Technical Specification. These print quality
characteristics are: native addressability, effective addressability, edge blurriness, edge raggedness, and the
printing system modulation transfer function (MTF).
Native or physical addressability refers to the imaging framework in a digital printing process, usually a
rectangular grid of printable spots, which enables depiction of fine spatial detail. Native addressability
specifies only one facet of the perceived resolution of a printing system.
Effective addressability is a measure of the minimum pitch by which the centre of a printed object (e.g. line
segment) can be displaced and evaluates the effects of imaged spot position modulation, size modulation, or
exposure modulation.
Edge blurriness provides an optical measure of the geometric transition width of an edge between an
unprinted substrate region and a printed solid area region.
Edge raggedness provides an optical measure of the geometric deviations of a printed edge from a requested
straight line.
The modulation transfer function (MTF) describes the ability of a linear imaging system to depict fine spatial
detail. The ability to depict fine spatial detail is affected by edge blurriness as well as the spot size of the
printer's marking technology and any adjacency effects that may occur in the reproduction of fine detail. Two
measurement methods are described that provide estimates of the printing system's modulation transfer
function including contributions from edge blurriness, spot-size and adjacency effects.
Verification of the measurement methods specified in this Technical Specification is underway.

vi © ISO/IEC 2012 – All rights reserved

TECHNICAL SPECIFICATION ISO/IEC TS 29112:2012(E)

Information technology — Office equipment — Test charts and
methods for measuring monochrome printer resolution
1 Scope
This Technical Specification defines methods for the objective measurement of the print quality characteristics
that contribute to the perceived resolution of reflection mode monochrome printed pages produced by digital
electro-photographic printers. The measurement methods of this Technical Specification are derived from
several existing techniques for the assessment of an imaging system's resolution characteristics. Each of
these measurement methods is intended for the engineering evaluation of a printing system's perceived
resolution and should not be used for purposes of advertising claims.
The methods of this Technical Specification are applicable only to monochrome prints produced in reflection
mode by electro-photographic printing technology. The current version of this Technical Specification is
intended for monochrome printers utilizing Postscript interpreters capable of accepting Postscript and
encapsulated Postscript (EPS) jobs.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 14524, Photography – Electronic still-picture cameras — Methods for measuring opto-electronic
conversion functions (OECFs)
ISO 16067-1, Photography — Spatial resolution measurements of electronic scanners for photographic
images — Part 1: Scanners for reflective media
ISO 21550, Photography — Electronic scanners for photographic images — Dynamic range measurements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
addressability
number of uniquely identifiable printable spot positions per unit distance
3.2
addressability, cross-track
addressability of the printer in the direction perpendicular to the motion of the print substrate through the
printer
© ISO/IEC 2012 – All rights reserved 1

3.3
addressability, effective
one over the minimum pitch by which the centre of a printed object can be displaced, with the constraint that
the objects compared are of constant dimension in the direction parallel to the centroid position change
direction
Note: The effective addressability of a printer may be greater than its native addressability. This higher
effective addressability is generally controlled algorithmically within the digital data path processing of
the printer and is generally not accessible to a user of the printer.
3.4
addressability, in-track
addressability of the printer in the direction parallel to the motion of the print substrate through the printer
3.5
addressability, native
one over the minimum pitch between adjacent spots that can be independently controlled and produced by
the printer
Note: Native addressability is commonly measured in dots per inch (dpi).
3.6
cycles per millimetre (cy/mm)
unit used for specifying spatial frequency
3.7
CMT Acutance (CMTA or Cascaded Modulation Transfer Acutance)
area under the system modulation transfer curve formed by multiplying (cascading) the individual component
modulation transfer functions and the human eye modulation response characteristic:
MT () = MT () x MT () . . . MT (), where one of the MTF functions is the modulation response
system 1 2 i
characteristic of the human eye, and denotes spatial frequency (cy/mm)
Note: See reference 1 (Bibliography) for further detail.
3.8
cross-track
oriented perpendicular to the direction of print substrate motion (cross-track direction)
3.9
edge blurriness
slowly changing transition between an unprinted substrate area and a solid printed area
Note: The measured optical width of the transition region perpendicular to the straight edge boundary
between an unprinted substrate area and a solid printed area provides an assessment of edge
blurriness.
3.10
edge raggedness
small deviations of an edge from expected straight line
Note: Measurement of the geometric deviations from straightness of a contour at a specific reflectance
ratio in the edge boundary region between the unprinted substrate area and the solid printed area of
a requested straight edge provides an assessment of edge raggedness.
3.11
edge transition width
distance between the points of a normal edge profile identified at 70% of the edge transition reflectance range
and 10% of that reflectance range, the region in which edge blurriness is measured
2 © ISO/IEC 2012 – All rights reserved

Note: The edge transition reflectance range is the reflectance difference between the maximum measured
reflectance factor, R , typically of the substrate, and the minimum measured reflectance factor, R ,
max min
typically of a region printed at a maximum printing value.
3.12
edge spread function
normalized spatial signal distribution in the scanned output of a printing system resulting from imaging a
theoretical infinitely sharp edge
Note: In measurement of the edge spread function, the tone-scale of the scanning system shall be
corrected to be linear in reflectance. See ISO 12231:2005.
3.13
human eye modulation response characteristic
the response of the human visual system to viewed sinusoidal modulation patterns as a function of the spatial
frequency of these modulation patterns
3.14
In-track
oriented along the direction of print substrate motion (in-track direction)
3.15
limiting resolution
spatial frequency at which the modulation of adjacent printed high-contrast lines and spaces is 10% of the DC
modulation capability of the printing system
3.16
line pairs per millimetre (lp/mm)
unit for specifying resolution in terms of the number of equal width black and white line pairs per millimetre
that can be resolved according to a criterion such as limiting resolution
3.17
modulation
difference between the maximum and minimum signal levels divided by the sum of these two levels
3.18
modulation transfer function
MTF
ratio, as a function of spatial frequency, of the measured modulation response in a print produced by a printing
system, to the stimulus modulation presented to that printing system
3.19
monochrome
printing using a single colorant, in particular, a single black colorant
3.20
normal edge profile
NEP
reflectance trace across the transition region perpendicular to the boundary of a straight edge between an
unprinted substrate area and a solid printed area
Note: The normal edge profile can be represented as the convolution of an edge spread function and an
infinitely sharp edge transition. In turn, the edge spread function is the Fourier transform of the
modulation transfer function of the linear system represented by the printing system.
3.21
nyquist limit
spatial frequency equal to one half the inverse of the sampling spacing for an adjacent pair of sampling points,
alternatively, one half of the spatial sampling frequency
© ISO/IEC 2012 – All rights reserved 3

3.22
pixel
smallest addressable element of a digital source image
3.23
raster image processor
RIP
component used in a printing system which produces a bitmap
3.24
reflectance factor
ratio of the reflected flux as measured to the reflected flux under the same geometrical and spectral conditions
for an ideal 100% diffuse reflecting surface
3.25
resolution enhancement technology
control of the printed spot position to a pitch that is less than the native addressability of the printing system
accomplished through local control of one or more spot characteristics, which are spot reflectance (gray-level
modulation), size of a spot (size modulation), or local position of a spot (position modulation)
3.26
Reflectance threshold
Level in the reflectance gradient profile of an edge that is at some specified percentage of the transition from
the minimum reflectance factor (R ) to the maximum reflectance factor (R ) as: R = R + p%(R –
min max p min max
R )
min
3.27
R
max
maximum measured reflectance factor, typically of the substrate
3.28
R
min
minimum measured reflectance factor, typically of a region printed at a maximum printing value
3.29
R
contour of points of an image element where the edge gradient profiles cross a reflectance level that is 10% of
the transition from the substrate reflectance factor (Rmax) to the minimum image reflectance factor (Rmin):
R10 = Rmin+10% (Rmax – Rmin)
3.30
R
contour of points of an image element where the edge gradient profiles cross a reflectance level that is 25% of
the transition from the substrate reflectance factor (Rmax) to the minimum image reflectance factor (Rmin):
R25 = Rmin+25% (Rmax – Rmin)
3.31
R
contour of points of an image element where the edge gradient profiles cross a reflectance level that is 40% of
the transition from the substrate reflectance factor (Rmax) to the minimum image reflectance factor (Rmin):
R40 = Rmin+40% (Rmax – Rmin)
3.32
R
contour of points of an image element where the edge gradient profiles cross a reflectance level that is 70% of
the transition from the substrate reflectance factor (Rmax) to the minimum image reflectance factor (Rmin):
R70 = Rmin+70%(Rmax – Rmin)
4 © ISO/IEC 2012 – All rights reserved

3.33
sampling interval
physical distance between a pair of adjacent sampling points, where adjacent sampling points are oriented
along the direction of print substrate motion (in-track direction), or perpendicular to the direction of print
substrate motion (cross-track direction)
3.34
sampling frequency
spatial frequency, measured in units of cy/mm, of adjacent sampling points where sampling points are
oriented along the direction of print substrate motion (in-track direction), or perpendicular to the direction of
print substrate motion (cross-track direction)
3.35
spatial frequency response
SFR
measured amplitude response of an imaging system as a function of spatial frequency
3.36
spot
smallest mark that can be placed under user control at a desired position on a printed page, independently
from all other adjacent marks
3.37
tangential edge profile
TEP
reflectance trace of a contour at a specific reflectance threshold along the printed rendition of a perfectly
straight edge boundary between an unprinted substrate area and a solid printed area
3.38
test chart
arrangement of test patterns designed to test particular aspects of a printing system
3.39
test pattern
specified arrangement of printable objects (test elements) designed to test particular aspects of a printing
system
3.40
tone-scale correction (scanner)
digital signal conversion that adjusts the relationship between the reflectance values of large imaged areas
and the corresponding digital code values
Note: Code values are the reflection scanner response to a scanned reflection stimulus (e.g. test chart)
tone-scale correction may be used to adjust the relationship between scanned pixel values and large
area reflectance to an aim relationship, e.g. scanned pixel values that have a linear relationship with
measured print reflectance.
4 Print resolution characteristics – methods for measurement and analysis
4.1 Compliance requirements
The print resolution characteristic measurement methods defined in this Technical Specification rely on the
objective evaluation of scanned images produced by printing test charts. The single exception to this is the
method for native addressability which relies on the visual evaluation of a printed test chart.
The test charts, the printing process employed to print test chart samples for evaluation, the measurement
methods, and the characteristics of the scanner employed for objective evaluation shall all meet compliance
requirements to ensure that the reported measurements are valid.
© ISO/IEC 2012 – All rights reserved 5

4.1.1 Test chart compliance
The test charts for this technical specification are specified in Annex A (normative), Test charts. These test
charts are included in the distribution media of this Technical Specification and are also available from the ISO
web site at http://standards.iso.org/ittf/PubliclyAvailableStandards/SC28_Test_Pages. The ZIP file
TS29112_TestCharts contains the current set of Test Charts for use with this Technical Specification.
The name and version of each test chart used in printer resolution assessment shall be recorded in the test
report.
These test charts are provided in Encapsulated Postscript (EPS) format. With Postscript compatible printers,
this format permits matching the test chart content to the addressability characteristics of the printer's raster
image processor (RIP).
4.1.2 Printing process compliance
The printing process specified in this Technical Specification avoids the re-interpretations of test chart content
provided by many imaging or graphics applications. The assessment of printer resolution characteristics is
thus made independent of application features and is therefore representative of the inherent capability of the
printer.
The procedure specified in Annex B (normative), Printing method, shall be used to submit the test charts for
this printer resolution assessment to the printer being assessed. The name of the printer, the settings of the
low-level printing application used to submit the test charts, and a specification of the printing application, as
specified in clause 6.2 and in Annex B, shall be recorded in the test report.
One or more pages shall be printed prior to running a test to ensure that the printer is properly warmed up.
4.1.3 Scanner characteristics compliance
Many of the measurement methods utilized in this Technical Specification employ a reflection scanner as an
analytic measurement device. These measurements will provide an accurate assessment of printer resolution
characteristics only if the scanner capabilities are sufficiently high that the scanner itself does not limit the
assessment and if the scanner control application is configured to deliver accurate and repeatable imagery.
Annex C, (Normative) Scanner conformance specifies the conditions that shall be met by a reflection scanner
and its scanner control application for qualification as a measurement device in the measurement methods of
this Technical Specification.
4.1.4 Measurement method compliance
The procedures specified in Annex D, (normative) Measurement method conformance, shall be used to
qualify the measurement method implementations used with this Technical Specification.
Failure to use a compliant implementation of the measurement methods defined in this Technical Specification
shall invalidate any test results obtained using that implementation. The name of the implementation and the
name of the implementer, or implementing organization, for each measurement method used in printer
resolution assessment shall be recorded in the test report.
4.2 Native addressability
Native addressability, often referred to as physical addressability, or simply addressability, may differ in the in-
track direction and in the cross-track direction of the printing process.
A Postscript printer RIP will provide a value for the printer addressability when queried. When printed, the test
chart for evaluating native addressability automatically obtains addressability values from the RIP.
Note: In most cases, evaluation of the printed target will simply verify the native addressability reported by the
printer's RIP.
6 © ISO/IEC 2012 – All rights reserved

4.2.1 Method for measuring native addressability
Unlike the other measurement methods specified in this Technical Specification, the native addressability of a
printing system is determined by visual evaluation. This visual evaluation procedure may be iterative.
Table 1, Native Addressability
Test chart: ADDIN180_TestChart.eps (per Annex A (Normative))
Test chart editing: (Optional) To over-ride addressability values reported by the RIP
Printing method: According to the procedure specified in Annex B (Normative)
Analysis method: Visual evaluation

Print the test chart file ADDIN180_TestChart.eps according to the method specified in Annex B (Normative),
Printing method. The native addressability test chart contains three sets of elements as shown in Figure 1.
Printing status and configuration check elements:
The native addressability reported by the RIP is shown here.
Two check elements are visually evaluated to verify that the
printing configuration allows correct assessment of the native
addressability test chart. All four checkerboard patterns and all
eleven levels of the tone scale ramp should be evident and distinct.
If not evident and distinct, a workflow or RIP configuration error is
indicated (improper resolution, high-contrast tone-scale, binary
rendition, etc.) which must be remedied before utilizing this target.
Coarse native addressability assessment scales:
Cross-track and in-track scales are provided to estimate the
approximate native addressability of a printing system. Moire
patterns in these elements disappear at the printer resolution.
Visual assessment of these positions and the adjacent
resolution scales provides an indication of the approximate
native addressability.
Fine native addressability assessment scales:
Cross-track and in-track scales are provided to estimate the
native addressability of a printing system to much higher      Figure 1. Native addressability test chart
precision.
Visual assessment of the position where the Moire patterns in these elements disappear provides a very
precise and accurate measure of the native addressability of the printing system under assessment.
The ADDIN180_TestChart.eps file queries the addressability characteristics of the printer's raster image
processor (RIP) and adjusts the test chart content to exactly match these reported addressability
characteristics.
Note: In most cases, evaluation of a printed page of the ADDIN180_TestChart.eps file will simply verify the
native addressability that is reported by the printer RIP and displayed in the upper right corner area of the
target. This reported value is correct if both of the following conditions are met:
1) The native addressability indicated by examination of the coarse native addressability assessment
scales is within two percent of the native addressability reported by the RIP.
2) The native addressability indicated by examination of the fine native addressability assessment
scales is within 0,2 pixels per centimetre (or 0,5 pixels per inch) of the native addressability reported
by the RIP.
If the in-track and cross-track native addressability indicated by examination of the in-track and cross-track
coarse and fine assessment scales are both within two percent of the value reported by the printer's RIP, then
the fine assessment scales are in range and the native addressability values obtained by visual evaluation of
both coarse and fine assessment scales should be considered as the true in-track and cross-track native
addressability of the printing system.
© ISO/IEC 2012 – All rights reserved 7

If the visual inspection results differ from the value reported by the RIP by more than two percent, then the fine
assessment scales will be out of range and will not provide an unambiguous measure of the printing system's
true native addressability. Further investigation is required and consists of three steps:
1) Open a renamed copy of the ADDIN180_TestChart.eps file in a text editor and edit the /SetDPI line in
this Postscript text file that is used to over-ride use of the RIP queried values for in-track and cross-track
native addressability values to reflect the values determined by visual inspection of the original sample
print of the native addressability target. The /SetDPI line of the Postscript text file is illustrated below.
/SetDPI 0 def % You can set the DPI that the program will adapt to. When
% set to zero, this will be done automatically, by checking the
% number of addressability steps per inch of the output device.
% Zero should be the normal setting. But, if it is necessary to
% adjust the center spi to show in the large squares (because
% the automatic adjustment is off center) then it is possible to
% set it here.
2) Print and evaluate the edited and saved test chart. When the coarse in-track and cross-track native
addressability obtained by evaluation of the most recently printed test chart are each within two percent
of the addressability values entered through the text editor into the defining fields of the test chart file,
then the fine native addressability scales are in range and visual evaluation can provide a measurement
of the true native addressability of the printing system that is accurate to within 0.2 pixels per centimetre
(or 0.5 pixels per inch). This is the tolerance required for evaluation of printer native addressability.
3) If visual inspection of the printed test chart still indicates an addressability outside the two percent range
of the fine native addressability scales, continue to refine the edited native addressability setting in the
Postscript file in order to evaluate the printing system native addressability by repeating steps 1 – 3.

Note: Usually one iteration of this process will be sufficient to provide an accurate estimate of the
native addressability of a printing system.
The values obtained through this evaluation process for in-track native addressability and for cross-track
native addressability shall be entered into the printer resolution test report as described in clause 6.3.
4.3 Effective addressability
The effective addressability of a printer may be greater than its native addressability. This higher effective
addressability is generally controlled algorithmically within the digital data path processing of the printer and is
generally not accessible to a user of the printer. The effective addressability of a printer may differ in the in-
track direction and in the cross-track direction.
4.3.1 Method for measuring effective addressability
Create a renamed copy of the files EffAddr03_IT.eps and EffAddr03_XT.eps. Open this copy in a text editor
and edit the line that specifies the native addressability of the printer to be tested.
Table 2, Effective Addressability
EffAddr03_IT.eps (per Annex A (Normative))
Test chart:
EffAddr03_XT.eps (per Annex A (Normative))
Test chart editing: (Required) To specify addressability
Printing method: According to the procedure specified in Annex B (Normative)
Scanner conformance: According to the procedure specified in Annex C (Normative)
Measurement conformance: According to the procedure specified in Annex D (Normative)
Reference analysis method: EffAddr_v03

Print the edited and saved test chart files according to the method specified in Annex B (Normative), Printing
method. The effective addressability test chart shall be edited, saved, and printed separately to evaluate in-
track effective addressability and to evaluate cross-track effective addressability.
8 © ISO/IEC 2012 – All rights reserved

The set of sample prints created by printing the edited and saved test chart files shall be scanned at a
resolution equal to or greater than the native addressability of the printing system being assessed or at a
scanning resolution that is at least half of the effective addressability of the printing system being assessed,
whichever is greater. Measurement of effective addressability may require re-scanning at a higher scan
resolution. (The test chart and measurement procedure are designed to allow the effective addressability to
exceed the scan resolution.) The scanner characteristics at this resolution shall conform to the requirements
specified in Annex C (normative), Scanner conformance, to provide valid lossless image files for analysis. An
illustrative region of a printed EffAddr03_IT.eps file is illustrated in Figure 2.

Figure 2. Effective Addressability test chart.
Analyze the scanned image files using the effective addressability measurement method defined in this
Technical Specification or a conforming implementation of this measurement method (Annex D.1, Effective
addressability measurement method). If the analysis shows two peaks, the effective addressability reported by
the analysis is obtained from the position of the second peak. If the analysis shows only a single peak, the
effective addressability test charts must be renamed, edited, saved, reprinted and reanalyzed until the
analysis shows two peaks. The process to be followed if the analysis shows only a single peak is as follows:
1. Open a re-named copy of the effective addressability test chart and edit the Postscript line specifying
the target resolution. Increase the target resolution multiplier by a factor of two from its previous value
(the initial value of the target resolution multiplier in any evaluation must be 2.) The effective
addressability of the printing system being assessed is the target resolution times the target resolution
multiplier.
2. Save and print the edited copy of the effective addressability test chart according to the method
specified in Annex B (Normative), Printing method.
3. These newly printed samples shall be scanned at a resolution equal to or greater than the native
addressability of the printing system being assessed or at a scanning resolution that is at least half of
the effective addressability of the printing system being assessed, whichever is greater. The scanner
characteristics at this resolution shall conform to the requirements specified in Annex C (normative),
Scanner conformance, to provide valid lossless image files for analysis.
4. Analyze the scanned image files using the effective addressability measurement method defined in
this Technical Specification or a conforming implementation of this measurement method (Annex D.1,
Effective addressability measurement method). If the analysis shows two peaks, the effective
addressability reported by the analysis is obtained from the position of the second peak. If the
analysis shows only a single peak, the process outlined in these steps 1 – 4 must be repeated until
two peaks are identified.
The result reported by this measurement method provides a measurement of the effective addressability
value of the printer for the selected test chart orientation. In-track effective addressability and cross-track
effective addressability are measured separately based on scans of the printed test chart sets created for
each of these two orientations. The values obtained for both in-track and for cross-track effective
addressability shall be entered into the printer resolution test report as specified in clause 6.3.
4.4 Edge blurriness and edge raggedness
Two characteristics of straight edges are of par
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