ISO/IEC 29112:2018
(Main)Information technology -- Office equipment -- Test pages and methods for measuring monochrome printer resolution
Information technology -- Office equipment -- Test pages and methods for measuring monochrome printer resolution
This document 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 document 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 is not intended to be used for purposes of advertising claims. The methods of this document are applicable only to monochrome prints produced in reflection mode by electro-photographic printing technology. This document is intended for monochrome printers utilizing PostScript®[1] interpreters capable of accepting PostScript and encapsulated PostScript (EPS) jobs. [1] PostScript® and Encapsulated PostScript® are registered trademarks for freely usable page description formats controlled and defined by Adobe Systems Incorporated. This information is given for the convenience of users of this document and does not constitute an endorsement by ISO/IEC.
Technologies de l'information -- Équipement de bureau -- Diagrammes et méthodes pour mesurer la résolution des imprimantes monochromes
General Information
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Standards Content (sample)
INTERNATIONAL ISO/IEC
STANDARD 29112
First edition
2018-11
Information technology — Office
equipment — Test pages and methods
for measuring monochrome printer
resolution
Technologies de l'information — Équipement de bureau —
Diagrammes et méthodes pour mesurer la résolution des imprimantes
monochromes
Reference number
ISO/IEC 29112:2018(E)
ISO/IEC 2018
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ISO/IEC 29112:2018(E)
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© ISO/IEC 2018
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ISO/IEC 29112:2018(E)
Contents Page
Foreword ..........................................................................................................................................................................................................................................v
Introduction ................................................................................................................................................................................................................................vi
1 Scope ................................................................................................................................................................................................................................. 1
2 Normative references ...................................................................................................................................................................................... 1
3 Terms, definitions and abbreviations ............................................................................................................................................ 1
3.1 Terms and definitions ....................................................................................................................................................................... 1
3.2 Abbreviations ........................................................................................................................................................................................... 6
4 Print resolution characteristics — Methods for measurement and analysis ........................................6
4.1 Conformance requirements ......................................................................................................................................................... 6
4.1.1 General...................................................................................................................................................................................... 6
4.1.2 Test page conformance ............................................................................................................................................... 6
4.1.3 Printing process conformance ............................................................................................................................. 7
4.1.4 Scanner characteristics conformance ............................................................................................................ 7
4.1.5 Measurement method conformance ............................................................................................................... 7
4.2 Native addressability ......................................................................................................................................................................... 8
4.2.1 General...................................................................................................................................................................................... 8
4.2.2 Method for measuring native addressability .......................................................................................... 8
4.3 Effective addressability ................................................................................................................................................................10
4.3.1 General...................................................................................................................................................................................10
4.3.2 Method for measuring effective addressability ..................................................................................10
4.4 Edge blurriness and edge raggedness .............................................................................................................................12
4.4.1 General...................................................................................................................................................................................12
4.4.2 Edge blurriness ..............................................................................................................................................................12
4.4.3 Edge raggedness ...................................................................... ......................................................................................13
4.4.4 Method for measuring edge blurriness and edge raggedness ...............................................14
4.5 Spatial frequency response .......................................................................................................................................................15
4.5.1 General...................................................................................................................................................................................15
4.5.2 Printer SFR estimation from edge characteristics ...........................................................................15
4.5.3 Method for measuring printer SFR from edge characteristics ..............................................15
4.5.4 Printer SFR estimation from 1-D repeating patterns ....................................................................16
4.5.5 Method for measuring printer SFR from 1-D repeating pattern characteristics ...16
4.6 ROI size and shape variation ....................................................................................................................................................18
5 Test set-up, configurations and procedure ............................................................................................................................18
5.1 Printer set-up and configuration ..........................................................................................................................................18
5.2 Printer testing environment .....................................................................................................................................................19
5.3 Substrate ...................................................................................................................................................................................................19
5.4 Test platform connection to the printer .........................................................................................................................19
5.5 Printing process ..................................................................................................................................................................................19
5.6 Test pages .................................................................................................................................................................................................19
5.7 Sample size ..............................................................................................................................................................................................20
5.8 Set-up procedure ................................................................................................................................................................................20
5.9 Testing procedure for visual evaluation .........................................................................................................................20
5.10 Testing procedure for scanner-based measurement ..........................................................................................21
6 Presentation of results ................................................................................................................................................................................21
6.1 General ........................................................................................................................................................................................................21
6.2 Required assessment configuration documentation ..........................................................................................22
6.3 Required assessment measurement documentation .........................................................................................23
Annex A (normative) Printing process ............................................................................................................................................................25
Annex B (normative) Scanner conformance .............................................................................................................................................30
Annex C (normative) Reference measurement methods and conformance ............................................................36
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ISO/IEC 29112:2018(E)
Annex D (informative) Reporting ..........................................................................................................................................................................53
Annex E (informative) Usage ......................................................................................................................................................................................59
Annex F (informative) Electro-photographic system measurement method verification example 65
Bibliography .............................................................................................................................................................................................................................87
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ISO/IEC 29112:2018(E)
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 JTC1.The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for
the different types of document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/iso/forward .html.This document was prepared by Technical Committee ISO/IEC JTC1, Information technology,
Subcommittee SC 28, Office equipment.This first edition cancels and replaces ISO/IEC TS 29112:2012.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.© ISO/IEC 2018 – All rights reserved v
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ISO/IEC 29112:2018(E)
Introduction
The purpose of this document is to provide a process for the objective measurement of print quality
characteristics that contribute to perceived resolution in pages printed on paper or similar opaque
materials using monochrome electro-photographic printing processes.This document prescribes the following:
— Definitions of 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) a well-documented printer and printing environment setup,
b) well-controlled printing of specified test pages, and
c) subsequent measurement of print quality characteristics using reflection scans of test pattern
elements on the printed test pages.— Definitions of methods for measuring the contributing print quality characteristics using printed
test pattern elements of the specified test pages and analysing the resulting data to derive 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 document. These
print quality characteristics are: native addressability, effective addressability, edge blurriness, edge
raggedness and the printing system spatial frequency response characteristic (SFR).
— 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. The common
unit for native addressability is DPI (dots per inch).— 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 spatial frequency response characteristic (SFR) describes the ability of a linear imaging system
to depict fine spatial detail. This is the spatial analogue of frequency response used to characterize
sound reproduction. A common synonym of the SFR characteristic is the modulation transfer
function (MTF). The ability to depict fine spatial detail is affected by edge blurriness and edge
raggedness as well as the spot size and shape of the printer's marking technology and any adjacency
effects that can occur in the reproduction of fine detail. Two measurement methods are described
that provide estimates of the printing system's spatial frequency response including contributions
from edge blurriness, edge raggedness, spot-size, spot shape and adjacency effects.
An essential part of the development of this document was verification that the specified measurement
methods correlate well with perceived printer resolution (the ability of a digital printing system to depict
fine spatial detail) and that the measurements are reproducible across laboratories and instruments.
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ISO/IEC 29112:2018(E)
The steps in and results of this process to verify the utility of the measurement methods specified in
this document are presented in more detail in Annex F. The applicability of the measurement methods
specified in this document could be expanded by undertaking similar verification processes with other
printing technologies.© ISO/IEC 2018 – All rights reserved vii
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INTERNATIONAL STANDARD ISO/IEC 29112:2018(E)
Information technology — Office equipment — Test
pages and methods for measuring monochrome printer
resolution
1 Scope
This document 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 document 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 is not intended to be used for purposes of advertising claims.
The methods of this document are applicable only to monochrome prints produced in reflection mode by
electro-photographic printing technology. This document is intended for monochrome printers utilizing
PostScript® interpreters capable of accepting PostScript and encapsulated PostScript (EPS) jobs.
2 Normative referencesThe following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 12233, Photography — Electronic still picture imaging — Resolution and spatial frequency responses
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 mediaISO/IEC 24790, Information technology — Office equipment — Measurement of image quality attributes
for hardcopy output — Monochrome text and graphic images3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp— IEC Electropedia: available at http: //www .electropedia .org
3.1.1
addressability
number of uniquely identifiable printable spot positions per unit distance
1) PostScript® and Encapsulated PostScript® are registered trademarks for freely usable page description
formats controlled and defined by Adobe Systems Incorporated. This information is given for the convenience of
users of this document and does not constitute an endorsement by ISO/IEC.© ISO/IEC 2018 – All rights reserved 1
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ISO/IEC 29112:2018(E)
3.1.2
bitmap
two-dimensional rectangular matrix of values representing the pixels (3.1.21) in a printed page
3.1.3cross-track
oriented perpendicular to the direction of print substrate motion (cross-track direction)
3.1.4cross-track addressability
addressability (3.1.1) of the printer in the direction perpendicular to the motion of the print substrate
through the printer3.1.6
edge blurriness
appearance of being hazy or indistinct in outline, giving a noticeable transition of density from a line
element to the background substrate whose transition width is zero for an ideally sharp edge
Note 1 to entry: 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.
3.1.7edge raggedness
appearance of geometric distortion of an edge from its ideal position
Note 1 to entry: 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.Note 2 to entry: An ideal edge should be absolutely straight along the length of a straight line.
3.1.8edge transition width
distance between the points of a normal edge profile (3.1.19) identified at 70 % of the edge transition
reflectance range and 10 % of that reflectance range, the region in which edge blurriness (3.1.6) is
measuredNote 1 to entry: 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,
maxR , typically of a region printed at a maximum printing value.
min
3.1.9
edge spread function
normalized spatial signal distribution in the scanned output of a printing system resulting from
imaging a theoretical infinitely sharp edgeNote 1 to entry: In measurement of the edge spread function, the tone-scale of the scanning system is corrected
to be linear in reflectance. See ISO 12231.3.1.10
effective addressability
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 directionNote 1 to entry: The effective addressability of a printer can 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.2 © ISO/IEC 2018 – All rights reserved
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ISO/IEC 29112:2018(E)
3.1.11
human eye modulation response
response of the human visual system to viewed sinusoidal modulation (3.1.15) patterns as a function of
the spatial frequency of these modulation patterns3.1.12
in-track
oriented along the direction of print substrate motion
3.1.13
in-track addressability
addressability (3.1.1) of the printer in the direction parallel to the motion of the print substrate through
the printer3.1.14
limiting resolution
spatial frequency at which the modulation (3.1.15) of alternating printed high-contrast lines and spaces
is 10 % of the zero-frequency spatial frequency response of the printing system3.1.15
modulation
difference between the maximum and minimum signal levels divided by the sum of these two levels
3.1.16modulation transfer function
MTF
spatial frequency response
SFR
ratio, as a function of spatial frequency, of the measured modulation (3.1.15) response in a print
produced by a printing system, to the stimulus modulation presented to that printing system
3.1.17monochrome
printing using a single colorant, in particular, a single black colorant
3.1.18
native addressability
one over the minimum pitch between adjacent spots (3.1.35) that can be independently controlled and
produced by the printer3.1.19
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 areaNote 1 to entry: For the edge blurriness measurement specified in this document, the transition region is
measured between the 10 % and 70 % reflectance levels.Note 2 to entry: The normal edge profile can be represented as the convolution of an edge spread function and
an infinitely sharp edge transition. In turn, for a linear system, the edge spread function is the Fourier transform
of the spatial frequency response (or modulation transfer function). For printing systems, which are usually not
linear systems, this latter relationship is only approximate.3.1.20
Nyquist limit
Nyquist frequency
spatial frequency equal to one half the inverse of the sampling spacing for an adjacent pair of
sampling pointsNote 1 to entry: This can also be expressed as one half of the spatial sampling frequency.
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ISO/IEC 29112:2018(E)
3.1.21
pixel
smallest addressable element of a digital source image
3.1.22
raster image processor
RIP
component used in a printing system which produces a bitmap (3.1.2)
3.1.23
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 surface3.1.24
resolution enhancement technology
control of the printed spot (3.1.36) position to a pitch that is less than the native addressability (3.1.18)
of the printing system accomplished through local control of one or more spot characteristics
Note 1 to entry: The spot characteristics are spot reflectance (gray-level modulation), size of a spot (size
modulation) or local position of a spot (position modulation).3.1.25
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 (3.1.27), to the maximum reflectance factor, R (3.1.26),
min maxas: R = R + p%(R – R )
p min max min
3.1.26
max
maximum measured reflectance factor (3.1.23), typically of the substrate
3.1.27
min
minimum measured reflectance factor (3.1.23), typically of a region printed at a maximum printing value
3.1.28contour 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, R (3.1.26), to the minimum image
maxreflectance factor, R (3.1.27): R = R + 10 % (R – R )
min 10 min max min
3.1.29
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, R (3.1.26), to the minimum image
maxreflectance factor, R (3.1.27): R = R + 25 % (R – R )
min 25 min max min
3.1.30
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, R (3.1.26), to the minimum image
maxreflectance factor, R (3.1.27): R = R + 40 % (R – R )
min 40 min max min
3.1.31
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, R (3.1.26), to the minimum image
maxreflectance factor, R (3.1.27): R = R + 70 % (R – R )
min 70 min max min
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ISO/IEC 29112:2018(E)
3.1.32
sampling efficiency
fraction of the Nyquist frequency (3.1.20) corresponding to the frequency where the spatial frequency
response characteristic (3.1.16) has dropped to 10% of its zero-frequency value3.1.33
sampling frequency
spatial frequency of adjacent sampling points where sampling points are conventionally oriented along
the direction of print substrate motion, the in-track direction (3.1.12), or perpendicular to the direction
of print substrate motion, the cross-track direction (3.1.3)3.1.34
scanner tone-scale calibration
opto-electronic conversion function
OECF
digital signal conversion that adjusts the relationship between the reflectance values of large imaged
areas and the corresponding digital code valuesNote 1 to entry: Code values are the reflection scanner response to a scanned reflection stimulus, e.g. test
elements (3.1.37). Scanner tone-scale calibration can 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.3.1.35
spot
smallest mark that can be placed under user control at a desired position on a printed page,
independently from all other adjacent marks3.1.36
tangential edge profile
TEP
array of geometric positions of a contour at a specific reflectance threshold (3.1.25) along the printed
rendition of a perfectly straight edge boundary between an unprinted substrate area and a solid
printed areaNote 1 to entry: For the edge raggedness measure specified in this document, the contour is taken at a 40 %
reflectance level....
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