ISO 14524:2009
(Main)Photography — Electronic still-picture cameras — Methods for measuring opto-electronic conversion functions (OECFs)
Photography — Electronic still-picture cameras — Methods for measuring opto-electronic conversion functions (OECFs)
ISO 14524:2009 specifies methods for the measurement of opto-electronic conversion functions (OECFs) of electronic still-picture cameras whose output is encoded as a digital image file. The OECF is defined as the relationship between the focal plane log exposures or scene log luminances, and the digital output levels of an opto-electronic digital image capture system. ISO 14524:2009 applies to both monochrome and colour electronic still picture cameras.
Photographie — Appareils de prises de vue électroniques — Méthodes de mesure des fonctions de conversion opto-électroniques
Fotografija - Digitalne kamere za mirujoče slike - Metode za merjenje optoelektronske prehodne funkcije (OECFs)
Ta mednarodni standard določa metode za merjenje optoelektronske prehodne funkcije (OECF) digitalnih kamer za mirujoče slike, katerih izhodni signal je kodiran kot datoteka z digitalno sliko. OECF je opredeljena kot razmerje med logaritmom ekspozicije goriščne ravnine ali logaritmom scenske svetlosti in ravnjo digitalnega izhodnega signala optoelektronskega sistema zajemanja digitalnih slik. Ta mednarodni standard velja za črno-bele in barvne digitalne kamere za mirujoče slike.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2011
)RWRJUDILMD'LJLWDOQHNDPHUH]DPLUXMRþHVOLNH0HWRGH]DPHUMHQMH
RSWRHOHNWURQVNHSUHKRGQHIXQNFLMH 2(&)V
Photography - Electronic still-picture cameras - Methods for measuring opto-electronic
conversion functions (OECFs)
Photographie - Appareils de prises de vue électroniques - Méthodes de mesure des
fonctions de conversion opto-électroniques
Ta slovenski standard je istoveten z: ISO 14524:2009
ICS:
37.040.10 Fotografska oprema. Photographic equipment.
Projektorji Projectors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
INTERNATIONAL ISO
STANDARD 14524
Second edition
2009-02-15
Photography — Electronic still-picture
cameras — Methods for measuring opto-
electronic conversion functions (OECFs)
Photographie — Appareils de prises de vue électroniques — Méthodes
de mesure des fonctions de conversion opto-électroniques
Reference number
©
ISO 2009
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
© ISO 2009
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
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2009 – All rights reserved
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Test methods. 3
4.1 General. 3
4.2 Camera OECF measurement . 4
4.3 Focal plane OECF measurement (method A) . 4
4.4 Alternative focal plane OECF measurement (method B). 4
5 Illumination. 5
5.1 Focal plane OECF measurement (method A) . 5
5.2 Alternative focal plane (method B) and camera OECF measurement. 5
6 Test conditions . 5
6.1 Temperature and relative humidity. 5
6.2 White balance (only applicable to colour cameras) . 5
6.3 Infrared-blocking (IR-blocking) filter. 6
6.4 Focus. 6
7 Input . 7
7.1 Focal plane log exposures. 7
7.2 Camera OECF chart log luminances. 7
8 Data analysis . 8
9 Presentation of results. 8
9.1 General. 8
9.2 Tabular presentation . 9
9.3 Graphical presentation. 11
Annex A (normative) ISO 14524 camera OECF test chart. 13
Annex B (informative) Relevance of the ISO 7589 spectral distribution index. 20
Annex C (informative) Reporting of the camera OECF in relative reflectance units. 22
Bibliography . 23
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 14524 was prepared by Technical Committee ISO/TC 42, Photography.
This second edition cancels and replaces the first edition (ISO 14524:1999), which has been technically
revised.
iv © ISO 2009 – All rights reserved
Introduction
This International Standard establishes standard methods for measuring the functional relationship between
the focal plane log exposures or scene luminances, and the digital output levels of a digital camera. This
information is required for the development and testing of digital cameras, is used in other electronic
still-picture camera measurement standards and may be helpful in the processing of digital image data.
An opto-electronic conversion function (OECF) measurement standard is required for several reasons, as
outlined below.
a) Well-established measurement methods have been used to determine the characteristic curves for
television cameras, where the characteristic curve is known as the “gamma correction” curve, and for
silver halide photography, where the characteristic curve is known as the “H&D” or “DlogH” curve.
However, these methods cannot be easily or unambiguously applied to the characterization of electronic
still-picture cameras.
b) The sampling and quantization processes found in digital systems present fundamental issues that need
to be addressed in a standardized manner.
c) The flexibility of digital systems complicates the determination and presentation of the functional
relationship between the camera's optical input and digital output levels. This International Standard
attempts to account for all the variables and ensure that results are presented in a consistent fashion.
The OECF of a digital camera might appear to be the analogue of the characteristic curve used in
photography and television, but this observation is only partly true. Characteristic curves show the relationship
between a physical input, such as log exposure or reflectance, and a physical output, such as density or volts.
The OECF, on the other hand, shows the relation between a similar physical input and a digital code value
assigned to the physical response produced by that input. Since this assignation can be arbitrary, digital
values themselves do not have physical meaning or units. For example, a change of a factor of two in digital
values could correspond to a doubling of the physical response to the input, to an order of magnitude change,
or to something else, depending on how the code values are assigned.
In digital photography applications, it is generally not necessary to know the physical response produced in a
digital camera. It is sufficient to know what digital values will be produced by a variety of inputs. Consequently,
this International Standard does not specify how to measure the true characteristic curve of a digital camera.
Rather, it specifies how to measure the relationship between the input to a digital camera and the digital code
values produced. These values are only absolutely meaningful in that they represent information. The
graphical reporting formats specified in this International Standard support this viewpoint by allowing OECFs
to be reported with either digital code values or bits on the vertical axis. This is the convention in information
theory. Users of this International Standard are advised that the actual physical response of a digital camera,
or of a complete digital photography system, can be linear, logarithmic, or something else, regardless of the
form of the OECF plot and whether digital code values or bits are reported on the vertical axis.
NOTE In accordance with the rules given in the ISO/IEC Directives, Part 2, commas are used rather than full-stops
as the decimal radix in this International Standard.
INTERNATIONAL STANDARD ISO 14524:2009(E)
Photography — Electronic still-picture cameras — Methods for
measuring opto-electronic conversion functions (OECFs)
1 Scope
This International Standard specifies methods for the measurement of opto-electronic conversion functions
(OECFs) of electronic still-picture cameras whose output is encoded as a digital image file. The OECF is
defined as the relationship between the focal plane log exposures or scene log luminances, and the digital
output levels of an opto-electronic digital image capture system.
This International Standard applies to both monochrome and colour electronic still-picture cameras.
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 5-1, Photography — Density measurements — Part 1: Terms, symbols, and notations
ISO 5-2, Photography — Density measurements — Part 2: Geometric conditions for transmission density
ISO 5-3, Photography — Density measurements — Part 3: Spectral conditions
ISO 5-4, Photography — Density measurements — Part 4: Geometric conditions for reflection density
ISO 516, Photography — Camera shutters — Timing
ISO 554, Standard atmospheres for conditioning and/or testing — Specifications
ISO 7589:2002, Photography — Illuminants for sensitometry — Specifications for daylight, incandescent
tungsten and printer
3 Terms and definitions
1)
For the purposes of this document, the following terms and definitions apply .
3.1
camera opto-electronic conversion function
camera OECF
relationship between the input scene log luminances and the digital output levels for an opto-electronic digital
image capture system
NOTE The units of measurement for this function are log candelas per square metre.
1) Additional definitions of interest can be found in ISO 12232.
ISO 14524:20
...
INTERNATIONAL ISO
STANDARD 14524
Second edition
2009-02-15
Photography — Electronic still-picture
cameras — Methods for measuring opto-
electronic conversion functions (OECFs)
Photographie — Appareils de prises de vue électroniques — Méthodes
de mesure des fonctions de conversion opto-électroniques
Reference number
©
ISO 2009
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
© ISO 2009
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
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2009 – All rights reserved
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Test methods. 3
4.1 General. 3
4.2 Camera OECF measurement . 4
4.3 Focal plane OECF measurement (method A) . 4
4.4 Alternative focal plane OECF measurement (method B). 4
5 Illumination. 5
5.1 Focal plane OECF measurement (method A) . 5
5.2 Alternative focal plane (method B) and camera OECF measurement. 5
6 Test conditions . 5
6.1 Temperature and relative humidity. 5
6.2 White balance (only applicable to colour cameras) . 5
6.3 Infrared-blocking (IR-blocking) filter. 6
6.4 Focus. 6
7 Input . 7
7.1 Focal plane log exposures. 7
7.2 Camera OECF chart log luminances. 7
8 Data analysis . 8
9 Presentation of results. 8
9.1 General. 8
9.2 Tabular presentation . 9
9.3 Graphical presentation. 11
Annex A (normative) ISO 14524 camera OECF test chart. 13
Annex B (informative) Relevance of the ISO 7589 spectral distribution index. 20
Annex C (informative) Reporting of the camera OECF in relative reflectance units. 22
Bibliography . 23
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 14524 was prepared by Technical Committee ISO/TC 42, Photography.
This second edition cancels and replaces the first edition (ISO 14524:1999), which has been technically
revised.
iv © ISO 2009 – All rights reserved
Introduction
This International Standard establishes standard methods for measuring the functional relationship between
the focal plane log exposures or scene luminances, and the digital output levels of a digital camera. This
information is required for the development and testing of digital cameras, is used in other electronic
still-picture camera measurement standards and may be helpful in the processing of digital image data.
An opto-electronic conversion function (OECF) measurement standard is required for several reasons, as
outlined below.
a) Well-established measurement methods have been used to determine the characteristic curves for
television cameras, where the characteristic curve is known as the “gamma correction” curve, and for
silver halide photography, where the characteristic curve is known as the “H&D” or “DlogH” curve.
However, these methods cannot be easily or unambiguously applied to the characterization of electronic
still-picture cameras.
b) The sampling and quantization processes found in digital systems present fundamental issues that need
to be addressed in a standardized manner.
c) The flexibility of digital systems complicates the determination and presentation of the functional
relationship between the camera's optical input and digital output levels. This International Standard
attempts to account for all the variables and ensure that results are presented in a consistent fashion.
The OECF of a digital camera might appear to be the analogue of the characteristic curve used in
photography and television, but this observation is only partly true. Characteristic curves show the relationship
between a physical input, such as log exposure or reflectance, and a physical output, such as density or volts.
The OECF, on the other hand, shows the relation between a similar physical input and a digital code value
assigned to the physical response produced by that input. Since this assignation can be arbitrary, digital
values themselves do not have physical meaning or units. For example, a change of a factor of two in digital
values could correspond to a doubling of the physical response to the input, to an order of magnitude change,
or to something else, depending on how the code values are assigned.
In digital photography applications, it is generally not necessary to know the physical response produced in a
digital camera. It is sufficient to know what digital values will be produced by a variety of inputs. Consequently,
this International Standard does not specify how to measure the true characteristic curve of a digital camera.
Rather, it specifies how to measure the relationship between the input to a digital camera and the digital code
values produced. These values are only absolutely meaningful in that they represent information. The
graphical reporting formats specified in this International Standard support this viewpoint by allowing OECFs
to be reported with either digital code values or bits on the vertical axis. This is the convention in information
theory. Users of this International Standard are advised that the actual physical response of a digital camera,
or of a complete digital photography system, can be linear, logarithmic, or something else, regardless of the
form of the OECF plot and whether digital code values or bits are reported on the vertical axis.
NOTE In accordance with the rules given in the ISO/IEC Directives, Part 2, commas are used rather than full-stops
as the decimal radix in this International Standard.
INTERNATIONAL STANDARD ISO 14524:2009(E)
Photography — Electronic still-picture cameras — Methods for
measuring opto-electronic conversion functions (OECFs)
1 Scope
This International Standard specifies methods for the measurement of opto-electronic conversion functions
(OECFs) of electronic still-picture cameras whose output is encoded as a digital image file. The OECF is
defined as the relationship between the focal plane log exposures or scene log luminances, and the digital
output levels of an opto-electronic digital image capture system.
This International Standard applies to both monochrome and colour electronic still-picture cameras.
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 5-1, Photography — Density measurements — Part 1: Terms, symbols, and notations
ISO 5-2, Photography — Density measurements — Part 2: Geometric conditions for transmission density
ISO 5-3, Photography — Density measurements — Part 3: Spectral conditions
ISO 5-4, Photography — Density measurements — Part 4: Geometric conditions for reflection density
ISO 516, Photography — Camera shutters — Timing
ISO 554, Standard atmospheres for conditioning and/or testing — Specifications
ISO 7589:2002, Photography — Illuminants for sensitometry — Specifications for daylight, incandescent
tungsten and printer
3 Terms and definitions
1)
For the purposes of this document, the following terms and definitions apply .
3.1
camera opto-electronic conversion function
camera OECF
relationship between the input scene log luminances and the digital output levels for an opto-electronic digital
image capture system
NOTE The units of measurement for this function are log candelas per square metre.
1) Additional definitions of interest can be found in ISO 12232.
3.2
digital output level
digital code value
numerical value assigned to a particular output level
3.3
electromechanical shutter
mechanical shutter which is electronically controlled
3.4
electronic still-picture camera
camera incorporating an image sensor that outputs an analogue or digital signal representing a still picture
and/or records an analogue or digital signal representing a still picture on a removable medium, such as a
memory card or magnetic disc
3.5
focal plane opto-electronic conversion function
focal plane OECF
relationship between the input focal plane log exposures and the digital output levels for an opto-electronic
digital image capture system
NOTE The units of measurement for this function are log lux seconds.
3.6
illuminance scale exposure series
series of exposures produced using a constant exposure time and a varying focal plane illuminance
3.7
incremental gain function
change in the output level (digital code value) divided by the change in the input level (luminance or exposu
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.