Digital imaging standards

Where's the Digital Handbook? 2004

Why standards?
Picture buyers can be excused a yawn or two when enthusiasts get going on the subject of digital standards – it can be 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, 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 a little confusion about exactly what can be standardised.

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 the 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.

Drivers 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 tyre 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.  (See Electric Lane Digital Spec). The ‘points to specify’, are common to all production cycles. The values may be different, but the check list 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 our Digital Spec 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!

(c) Sarah Saunders, Electric lane
Published in Visuell 2004