SIST ISO 15739:2011

INTERNATIONAL ISO
STANDARD 15739
First edition
2003-05-01
Photography — Electronic still-picture
imaging — Noise measurements
Photographie — Imagerie des prises de vue électroniques —
Mesurages du bruit
Reference number
©
ISO 2003
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 2003
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 2003 — All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references. 1
3 Terms and definitions. 1
4 Test conditions. 3
4.1 General. 3
4.2 Illumination. 3
4.3 Temperature and relative humidity . 4
4.4 White balance. 4
4.5 Infrared (IR) blocking filter . 4
4.6 Photosite integration time. 4
4.7 Colour noise weighting . 4
4.8 Compression. 4
5 Noise measurement procedures . 5
5.1 General. 5
5.2 Uniform field noise measurement methods. 5
5.3 Cameras with removable lenses . 5
5.4 Whole camera. 6
5.5 Density measurements for methods 5.3 and 5.4 . 7
5.6 Test chart noise measurements . 7
6 Calculation and reporting of results . 8
6.1 General. 8
6.2 Signal-to-noise ratios — large area. 9
6.3 ISO DSC dynamic range. 10
6.4 Visual noise measurements. 11
6.5 Evaluation of noise measurements with software . 11
Annex A (normative) Test chart . 12
Annex B (normative) Noise component analysis. 15
Annex C (informative) Visual noise measurements. 18
Annex D (informative) Method for measuring edge noise. 22
Annex E (informative) Incremental gain calculation . 24
Bibliography . 26

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 15739 was prepared by Technical Committee ISO/TC 42, Photography.
iv © ISO 2003 — All rights reserved

Introduction
Noise is an important attribute of electronic photographic systems. Standardization assists users and
manufacturers in determining the quality of images that may be obtained from an electronic still-picture
camera. The camera noise measurements described in this International Standard are performed in the digital
domain, using digital analysis techniques. For electronic cameras that include only analogue outputs, the
analogue signal has to be digitized, so that the digital measurement can be performed. The digitizing
equipment has to be characterized, so that the effects of the digitization can be removed from the
measurement results. When this is not possible, the type of digitizing equipment used is to be reported along
with the measurement results.
Since the noise performance of an image sensor may vary significantly with exposure time and operating
temperature, these operating conditions are specified. The visibility of noise to human observers depends on
the magnitude of the noise, the apparent tone of the area containing the noise and the spatial frequency of the
noise. The magnitude of the noise present in an output representation depends on the noise present in the
stored image data and the contrast amplification or gain applied to the data in producing the output. The noise
visibility is different for the luminance (or monochrome) channel and the colour (or colour difference) channels.
Therefore, this International Standard accounts for these factors in measuring and reporting the camera noise
measurements. Annex A gives the construction of an ISO standard camera noise test chart. Annex B specifies
the method for determining the components of the digital camera noise from a number of samples. Annex C
describes a procedure using a human visual model as a method for weighting the spectral components of the
noise.
Many electronic still-picture cameras use extensive signal processing to reduce noise in uniform areas, and
the noise levels measured in the large area test defined in this International Standard may not be
representative of the noise levels found in the pictures taken by the camera. Therefore, new methods of
measuring edge noise have been investigated. One method is described in Annex D. The incremental gain
calculation is given in Annex E.

INTERNATIONAL STANDARD ISO 15739:2003(E)

Photography — Electronic still-picture imaging — Noise
measurements
1 Scope
This International Standard specifies methods for measuring and reporting the noise versus signal level and
dynamic range of electronic still-picture cameras. It 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 7589:2002, Photography — Illuminants for sensitometry — Specifications for daylight, incandescent
tungsten and printer
ISO 12232:1998, Photography — Electronic still-picture cameras — Determination of ISO speed
ISO 14524:1999, Photography — Electronic still-picture cameras — Methods for measuring opto-electronic
conversion functions (OECFs)
ITU-R BT.709-5, Parameter values for the HDTV Standards for production and International programme
exchange
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
camera opto-electronic conversion function
camera OECF
opto-electronic conversion function
focal plane opto-electronic conversion function
relationship between the input scene log luminances and the digital output levels for an opto-electronic digital
capture system
NOTE The units of measurement for this function are log candelas per square metre.
3.2
digital output level
digital code value
numerical value assigned to a particular output level
3.3
digital still camera
DSC
camera incorporating an image sensor which outputs a digital signal representing a still picture, or records a
digital signal representing a still picture on a removable medium, such as a memory card or magnetic disk
3.4
electronic still-picture camera
camera incorporating an image sensor which 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 disk
3.5
image sensor
electronic device which converts incident electromagnetic radiation into an electronic signal
NOTE A charge coupled device (CCD) array is an example of an electronic signal.
3.6
incremental gain function
change in the output level (digital code value) divided by the change in the input level (luminance or exposure)
as a function of the light level
NOTE 1 For the determination of incremental gain values, log input values are not used.
NOTE 2 If the input exposure points are very finely spaced and the output noise is small compared to the quantization
interval, the incremental gain function can have a jagged shape. Such behaviour is an artefact of the quantization process
and is removed by using an appropriate smoothing algorithm, or by fitting a smooth curve to the data. In some cases, it
may be desirable to fit a curve to the input-output data and then determine the incremental gain function by taking the first
derivative of the function used for the curve fit.
3.7
incremental output signal
input level (luminance or exposure, not logged) multiplied by the system incremental gain at that level
3.8
incremental signal-to-noise ratio
ratio of the incremental output signal to the root mean square (rms) noise level, at a particular signal level
NOTE This is typically expressed as a graph or table showing the rms noise level versus output signal level for the
full range of output signal levels.
3.9
ISO DSC dynamic range
ratio of the maximum luminance level which appears unclipped to the minimum luminance level which can be
reproduced with an incremental signal-to-temporal-noise ratio of at least 1, as determined in accordance with
ISO 15739
3.10
noise
unwanted variations in the response of an imaging system
3.10.1
total noise
all the unwanted variations captured by a si
...