Street Photography Magazine

already been ISO certified (ISO 16684-1:2012).
However, we also predict that the sometimes
confusing mass of currently available formats
will keep us busy for a while to come.

What about Duplicate

Metadata?

It is always advisable to avoid redundancy in
an image database. However, because the Exif
and IPTC/XMP standards come from different
sources, some data fields – such as copyright
information – are duplicated.
We recommend that you use camera
settings that include Exif data for all the data
fields you want to cover. It is nevertheless a
good idea to save separate information (in
the above example, copyright data) to the
appropriate IPTC data field as well. Unlike
Exif metadata, IPTC data is still the standard

that many agencies and photographers

expect their customers and business

partners to use.

Metadata and Face Recognition

Standardized formats for strroage of people’s

names and the positions of faces within an

image have only recently been addressed. The

IPTC standard has always contained a field for

names, but includes no practical way to save

positional information. The XMP standard was

adapted to include positional information in

2010, but the necessary support is still lacking

in most metadata editing software. However,

if you open a JPEG image using a full-featured

text editor such as Notepad++, any name tags

and localization data that your database

software has written to an image can be

found using a text search.

Switching Databases

Database software saves metadata not only to

image and sidecar files, but also to the

database itself, often using proprietary

formats and non-standard locations. Such

practice makes it difficult to stick to globally

accepted metadata standards. For example,

Picasa saves name tags created using its face

recognition functionality in its own picasa.ini

file and not to the predefined IPTC name field.

If you should decide to switch databases,

information like this will be lost. Your new

program will need to have extremely

powerful export functionality if you want to

rescue and re-use all the metadata created

using your previous database program.

Before you spend a lot of time and effort

writing and saving metadata, always check

which parts of the data you create can be

easily exported should you decide to switch

programs later. In multi-user scenarios,

individual image metadata, once mported, is

updated (if at all) via the database interface.

In such cases, the image files themselves

can only be altered at the export stage, and

many administrators use the opportunity to

update image metadata. This approach is fine

in an enterprise environment, but is less

suitable for single-user scenarios. For home

users, we recommend writing important

metadata directly to your files or to an XMP

sidecar.

If you follow our recommendations

meticulously, face recognition will be reduced

to a virtually useless ‘fun’ function. The

standards that do exist have only been

half-heartedly implemented. For example,

Image Database Software | Metadata

IPTC data fields are precisely defined, but not every software

manufacturer adheres to the prescribed definitions. Discrepancies

often affect the descriptions and character sets that can be used.

IPTC gives manufacturers a free hand, so it is important that the

intended character set is itself defined in the appropriate field.

These definitions are all too often ignored by software

applications, which means that the operating system’s default

character set is used, leading to rows of question marks where the

image metadata includes special characters that the operating

system doesn’t recognize.

Because it is based on XML, which is Unicode-based, XMP prevents

such anomalies. If you want to be doubly sure that your keywords

will be correctly recognized, you can always use good old ASCII.

This approach is time-consuming and means you can’t use special

characters, but you can be sure that the characters you use will be

reproduced correctly.

IPTC Metadata and Special Characters

Lightroom’s default setting only writes

metadata directly to image files if you save

them manually. This setting can be changed

in the program’s Preferences dialog.