ISO/IEC TS 29112:2012
(Main)Information technology — Office equipment — Test charts and methods for measuring monochrome printer resolution
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
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Standards Content (Sample)
TECHNICAL ISO/IEC
SPECIFICATION TS
29112
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 TS 29112:2012(E)
©
ISO/IEC 2012
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ISO/IEC TS 29112:2012(E)
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ii © ISO/IEC 2012 – All rights reserved
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ISO/IEC TS 29112:2012(E)
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
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ISO/IEC TS 29112:2012(E)
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
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ISO/IEC TS 29112:2012(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 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.
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ISO/IEC TS 29112:2012(E)
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.
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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
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ISO/IEC TS 29112:2012(E)
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
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ISO/IEC TS 29112:2012(E)
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
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ISO/IEC TS 29112:2012(E)
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
10
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
25
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
40
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
70
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)
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ISO/IEC TS 29112:2012(E)
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.
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ISO/IEC TS 29112:2012(E)
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_T
...
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