Where’s
the Handbook? Making Sense of Digital Standards.
Text copyright Sarah Saunders, all rights reserved
Why
standards?
Picture
buyers can be excused a yawn or two when enthusiasts get going on the
subject of digital standards – it can be a pretty dense subject,
and is perhaps best left to the learned committees who deal with such
things. Or is it?
There
is increasing evidence that end users of pictures need to get involved,
for their own benefit. Publishers struggle daily with a hotch-potch of
images crossing their desks. Images of unknown and variable quality waltz
through the production cycle without so much as a ‘by your leave’,
landing close to deadline, on the desk of the unfortunate production executive
or designer. If the images are not up to scratch, the choice is either
to pay large sums to a repro house to ‘put things right’ or
to fight against the deadline to replace the picture. Not a happy state
of affairs.
It’s
fairly obvious that people need to know that the images or scans they
receive from suppliers are in standard accepted formats and reach a certain
standard in terms of quality. The ‘standards debate’ is about
both these aspects, but there has been not just a little confusion about
exactly what can be standardized.
One
of the problems for the people who really need the standards is that the
debate has been dominated by specialists at both ends of the workflow
– photographers and printers. In the past this made sense, as the
transparency passed more or less intact between the two ends of the production
cycle. Things are much more fluid now, and the people sandwiched in the
middle have a pressing need to know the nature and characteristics of
the files they are handling. This is a good place to start; un-tamed,
the standards beast can be unwieldy, leaving people more confused than
before.
Driver's
handbook
Education
is clearly needed, but busy picture buyers should not have to understand
all the issues which photographers and printers have to grapple with.
Think of car drivers. They are told what tire pressure to use, where to
fill the tank, how often to service the car and so on. They do not need
to be mechanics. The picture industry, in other words, needs a driver’s
handbook.
The
first task is to list the characteristics which define a usable image
file. We need a checklist of properties – a passport which allows
the image to be checked at quality control gates before it goes into production.
We have called this checklist ‘Image-ID,’ and have reproduced
a sample of how it might look. The ‘points to specify’ are
common to all production cycles. The values may be different, but the
checklist is the same.
We
have added a typical specification for publishing, which can be used in
the absence of any other information. But anyone in charge of a company
or department receiving images needs to consider what they need for their
own end use or uses.
Who
should set standards?
Standards
are not theoretical constructs - they need to be set by the people receiving
and using the images. The process works backwards from printer to publisher
to picture library to photographer. The problem now is that many picture
libraries and publishers are letting photographers and scanning houses
define the picture supply. Although standards clearly need to embrace
what is possible for the supplier, the thrust has to be in the right direction.
If I go into a shop for blue trousers of a certain size, I won’t
accept red trousers in a different size, which don’t fit and don’t
suit. Why should scans be any different?
The
situation is confounded by the fact that photographers are often badly
under-skilled themselves. The number of irreversibly damaged picture files
circulating around picture desks attests to that. Even scanning houses
and picture libraries are not immune. The excuse ‘our customers
don’t complain’ is common. Perhaps they don’t; but time
will take care of that. As customers become more digitally savvy and start
to apply standards and quality control, some suppliers will be left with
egg on their faces. And picture libraries, if they don’t address
the issues now, will be left with thousands of scans which are not worth
archiving for the future – an investment down the drain.
Principles
for image supply
Wherever
you are in the production chain, there are common principles which should
guide the supply of image files. They are: carry as much picture information
as possible; use standard public formats and colour spaces; enable easy,
cross-platform file transfer; fit your standards to the realities and
the economies of the end-use; and let your customer know exactly what
you are supplying.
Quality
control
Quality
control is clearly an important part of the process. Some checks can be
automated, but before you let your imagination stray too far down that
road (remember the picture libraries which were going to run themselves?)
be aware that quality control will always require a person to view the
picture. You can automate checking for file size, file format, colour
space, resolution; but a machine can’t tell for example whether
the file has been previously compressed, or whether the sky is really
supposed to be magenta.
The
name of the game is communication, and there is too little of it going
on at the moment. If you are confused, just use the Image ID list to specify
what you want. It really is up to the picture suppliers to get it right.
But remember to put checks in place to make sure they are delivering!
What
about metadata?
People
wondering about where to put captions and picture credits will cry out
for standards in that area as well. That’s a whole subject in itself
– suppliers and users of pictures will have to get together to hammer
out solutions to that particular muddle, and standardize the way information
is noted and retrieved.
DIGITAL
IMAGE SPECIFICATIONS
Source: Electric
Lane
|
Points
to specify |
Typical
spec. absent other information |
Notes |
| File
size |
According
to output size |
Final
use according to output size and resolution. |
| Resolution |
300dpi |
This
is an accepted convention for much of publishing, although some sectors
may specify differently for output. |
| Format |
JPEG
or TIFF (8 bit/channel file) |
Definitely
NOT RAW files, which should be converted to one of these standard
formats. |
| Extras |
No
layers or extra channels or annotations |
|
| Compression |
Not
less than level 8 JPEG, sometimes none |
TIFF
files should not be delivered in compressed form, for example, TIFF
with JPEG compression. |
| Colour
space |
Adobe
RGB 1998 |
The
standard independent colour space for delivery of RGB files. |
| |
or
CMYK Euroscale coated or ISO Web coated |
Standard
independent colour spaces for delivery of CMYK files in Europe (in
the absence of information about the destination printing press).
ISO Web coated is recommended by Pic4press (www.pass4press.com). |
| |
|
Files
delivered specifically for web use should be converted to an agreed
colour space (usually sRGB) and colour profiles should be removed
(unless requested). All file info should be removed and no sharpening
applied unless requested. (Web designers sometimes blur images to
reduce their size.) |
| Image
file tagging (colour profile) |
Attach
colour profile |
The
profile should be that of the device-independent working colour space
(Adobe RGB 1998, CMYK Eurocoated, ISO Web coated). Although the RGB
colour profile is small, the CMYK profile will add about 0.5 MB to
the CMYK file size. Although profiles may be dropped at printing stage,
it is important that they are attached at previous stages. |
| Sharpening |
Minimal
or none, until final output image size is known |
|
| Cleaning |
Cleaned
to 50 or 100% |
|
| Colour
balance |
Files
should be colour balanced |
Archival
files should show the maximum tonal range for the subject. Generally
there should be no clipping unless the image requires it. |
| Colour
correction |
Free
of unwanted colour casts |
The
extent of colour correction needs to be defined. In general, the file
should be free of colour casts - i.e. colour neutral, unless a colour
cast is part of the composition. |
| File
extensions attached |
Always
attach file extensions |
NB
Mac users - this is a preference setting in Photoshop. Essential to
transfer between Mac and PC platforms. |
| Caption
material |
IPTC/XML
or text file |
Caption
and credit info should be included in File Info. The industry is currently
working on standards. |
| Labeling |
According
to workflow |
|
| Interpolation |
No
interpolation, or specify amount and acceptable methods |
|
NOTES:
The specifications should be reviewed at least annually to take account
of changes in technology.

Sarah
Saunders is an expert in picture archiving and commercial image sales,
with a background in photography and picture library management. She runs
Electric Lane,
a training and consultancy company which works with publishers, picture
libraries and photographers to help them achieve productive and high quality
results from their digital workflow She is chair of the Metadata Group
for BAPLA (British Association of Picture Libraries and Agencies, www.bapla.org.uk)
and has contributed to the Pic4Press digital image Guidelines (www.ppa.co.uk/pass4press/pic4press.html).
Feel
free to send your comments on this article to the
at NatureScapes.Net.

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