Street Photography Magazine

W

atermarks are old hat in the analog
world. They are used on banknotes and
stamps to help prevent illegal copying, and on
writing paper as a manufacturer’s label and a
sign of quality. Watermarks have long been a
familiar part of our everyday digital lives, and
visible watermarks are a tried and trusted tool
at image portals such as Fotolia. Invisible
watermarks offer various advantages over
visible ones, but require dedicated software if
you want to use and analyze them properly.
Digital watermarks are generally simpler
to remove or manipulate than their analog
counterparts, and most home computers have
a range of tools installed that can be used for
just that purpose. The intended use for a photo
will determine which type of watermarking
technique is most appropriate.

Why Use Watermarks?

Digital image protection is a form of medicine
that unfortunately cannot be used without
producing side effects. Visible watermarks
mar the look of an image, while invisible
watermarks can, under certain circumstances,
reduce image quality. Embedding any kind of
watermark involves effort that will, ideally,
save time and money in the long run, but
whether you use a watermark at all will

depend on how you wish to use your images.

If, for example, you sell your images as

postcards via a website that includes

thumbnails of your products, the tiny size of

the published images makes them useless to

potential pirates. And, should your thumbnails

turn up elsewhere, they are unlikely to cause

any real commercial damage to your sales of

printed postcards.

The situation is quite different if you create

images specifically for commercial use on the

Internet. In this case, every image sold is the

perfect raw material for an illegal copy, and

every pirated copy reduces your potential

income from legitimate channels. Once you

have decided to use watermarks, you need to

decide whether to take the visible or invisible

route. Each approach has its own particular

advantages and disadvantages, and there is

no ideal solution.

Visible Watermarks ‘Brand’

Your Images

Creating a visible watermark is, technically

speaking, a trivial task, and every halfway

decent image processing program includes

the necessary tools. These use various

techniques, but all produce a watermark that

behaves like a kind of stamp on the ‘surface’

of the image. This approach usually spoils the

appearance of the image, although a

watermark that is too subtle – such as a string

of letters at the edge of the image – can

simply be cropped away; watermarks have to

cover a large part of an image to be effective.

Nevertheless, it is still possible to remove most

visible watermarks if you are prepared to put

in some effort retouching. The techniques

used to remove watermarks are similar to

those used in digital image restoration, but

are usually too time-consuming to make it

image piracy worthwhile. To put it simply: if

stealing involves more work than taking the

legal route, no-one will bother trying.

Online stock photo agencies like Fotolia use

semi-transparent visible watermarks that make

the images less attractive to would-be thieves.

These aren’t necessarily a problem in purely

documentary images, but make a big

difference if they are plastered across the

middle of a romantic sunset under palm trees.

Visible watermarks are the simplest way to

effectively protect online images against theft

and make it impossible for third parties to use

stolen images without revealing their source.

They are internationally recognized, and every

user can see who an image belongs to

without having to make any additional

technical effort.

Invisible Watermarks | Introduction

Online stock agencies such as Fotolia protect their low-resolution thumbnails and high-resolution
images with obvious visible watermarks. Purchased images don’t have watermarks.

Image: de.fotolia.com