SIST ISO 16067-2:2011

INTERNATIONAL ISO
STANDARD 16067-2
First edition
2004-10-15
Photography — Electronic scanners for
photographic images — Spatial
resolution measurements —
Part 2:
Film scanners
Photographie — Scanners électroniques pour images
photographiques — Mesurages de la résolution spatiale —
Partie 2: Scanners pour films
Reference number
©
ISO 2004
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ii © ISO 2004 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references . 1
3 Terms and definitions. 1
4 Test chart . 4
4.1 Representation and recommended size .4
4.2 General characteristics of the test chart . 4
4.3 Test chart elements . 6
5 Test conditions. 7
5.1 General. 7
5.2 Temperature and relative humidity . 8
5.3 Luminance and colour measurements .8
5.4 Linearization . 8
5.5 Scanner settings . 8
6 Measuring the scanner OECF. 8
7 Limiting visual resolution and its relation to SFR . 8
8 Edge SFR test measurement . 9
9 Presentation of results . 9
9.1 General. 9
9.2 Scanner OECF . 10
9.3 Resolution Measurements . 11
Annex A (normative) Scanner OECF test patches. 13
Annex B (informative) SFR algorithm. 14
Annex C (informative) Using slanted edge analysis for colour spatial registration measurement . 17
Bibliography . 19

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. Each 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 part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. 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.
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 16067-2 was prepared by Technical Committee ISO/TC 42, Photography.
ISO 16067 consists of the following parts, under the general title Photography — Electronic scanners for
photographic images — Spatial resolution measurements:
 Part 1: Scanners for reflective media
 Part 2: Film scanners
iv © ISO 2004 – All rights reserved

Introduction
One of the most important characteristics of an electronic film scanner is the ability to capture the fine detail
found in the original film. This ability to resolve detail is determined by a number of factors, including the
performance of the scanner lens, the number of addressable photoelements in the image sensor(s) used in
the scanner, and the electrical circuits in the scanner. Different measurement methods can yield different
metrics that quantify the ability of the scanner to capture fine details.
This International Standard specifies methods for measuring the limiting visual resolution, and spatial
frequency response calculated from a slanted edge (Edge SFR) imaged by a film scanner. The scanner
measurements described in this International Standard are performed in the digital domain, using digital
analysis techniques. A test chart of appropriate size and characteristics is scanned and the resulting data is
analysed. The test chart described in this International Standard is designed specifically to evaluate
continuous tone film scanners. It is not designed for evaluating electronic still-picture cameras, video cameras,
or bi-tonal document scanners.
The edge SFR measurement method described in this International Standard uses a computer algorithm to
analyse digital image data from the film scanner. Pixel values near slanted vertical and horizontal edges are
used to compute the SFR values. The use of a slanted edge allows the edge gradient to be measured at
many phases relative to the image sensor photoelements, so that the SFR can be determined at spatial
frequencies higher than the half sampling frequency, sometimes called the Nyquist limit. This technique is
mathematically equivalent to a moving knife-edge measurement.
Part 1 of this International Standard deals with reflective media.
INTERNATIONAL STANDARD ISO 16067-2:2004(E)

Photography — Electronic scanners for photographic
images — Spatial resolution measurements —
Part 2:
Film scanners
1 Scope
This International Standard specifies methods for measuring and reporting the spatial resolution of electronic
scanners for continuous tone photographic negatives and reversal (e.g. slide) films. The International
Standard applies to both monochrome and colour film scanners.
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 5-2, Photography — Density Measurements — Part 2: Geometric conditions for transmission density
ISO 554, Standard atmospheres for conditioning and/or testing — Specifications
ISO 12231, Photography — Electronic still-picture cameras — Terminology
ISO 12233, Photography — Electronic still-picture cameras — Resolution Measurements
ISO 14524, Photography — Electronic still-picture cameras — Methods for measuring opto-electronic
conversion functions (OECFs)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12231 and the following apply.
3.1
addressable photoelements
number of active photoelements in an image sensor
NOTE This is equal to the number of active lines of photoelements, multiplied by the number of active photoelements
per line.
3.2
aliasing
reconstructed image artefacts in sampled imaging systems where the combined spatial frequency energy of
the input image and scanner combination is significant beyond the half-sampling frequency of the scanner
NOTE These artefacts usually manifest themselves as moiré patterns in repetitive image features or as jagged stair
stepping at edge transitions.
3.3
digital output level
numerical value assigned to a particular output level, also known as the digital code value
3.4
edge spread function
ESF
normalized spatial signal distribution in the linearized output of an imaging system resulting from imaging a
theoretical infinitely sharp edge
3.5
effectively spectrally neutral
having spectral characteristics that result in a specific imaging system producing the same output as for a
spectrally neutral object
3.6
electronic scanner for photographic films
scanner incorporating an image sensor that outputs a digital signal representing a still film image
3.7
fast scan direction
scan direction corresponding to the direction of the alignment of the addressable photoelements in a linear
array image sensor
3.8
gamma correction
process that alters the image data in order to modify the tone reproduction
3.9
image sensor
electronic device that converts incident electromagnetic radiation into an electronic signal; e.g. a charge
coupled device (CCD) array
3.10
resolution
measure of the ability of a digital image capture system, or a component of a digital image capture system, to
capture fine spatial detail
NOTE Resolution measurement metrics include resolving power, limiting visual resolution, SFR, MTF and CTF.
3.11
sampled imaging system
imaging system or device which generates an image signal by sampling an image at an array of discrete
points, or along a set of discrete lines, rather than a continuum of points
NOTE The sampling at each point is done using a finite size sampling aperture or area.
3.12
sample spacing
physical distance between sampling points or sampling lines, measured in units of distance (e.g. µm, mm)
NOTE The sample spacing may be different in the two orthogonal sampling directions.
3.13
sampling frequency
reciprocal of sample spacing
NOTE Expressed in samples per unit distance (e.g. dots per inch).
2 © ISO 2004 – All rights reserved

3.14
scanner
electronic device that converts a fixed image, such as a film or film transparency, into an electronic signal
3.15
scanner opto-electronic conversion function
scanner OECF
relationship between the input density and the digital output levels for an opto-electronic digital capture system
3.16
slow scan direction
direction in which the scanner moves the photoelements (perpendicular to the lines of active photoelements in
a linear array image sensor)
3.17
spatial frequency response
SFR
R
SFR
measured amplitude response of an imaging system as a function of relative input spatial frequency
NOTE 1 The SFR is normally represented by a curve of the output response to an input sinusoidal spatial luminance
distribution of unit amplitude, over a range of spatial frequencies. The SFR is normalized to yield a value of 1,0 at a spatial
frequency of 0.
NOTE 2 In equations, the symbol R rather than the abbreviation SFR is used for clarity.
SFR
3.18
spectrally neutral
test chart in which the relative spectral power distributions of the incident and reflected (or transmitted) light
are equal
3.19
test chart
arrangement of test patterns designed to test particular aspects of an imaging system
3.2
...