Street Photography Magazine

don’t need to use Photoshopas your host
application. The downside of the low price
and product simplicity is slightly clunky
handling, slow processing and watermarks
that don’t win any prizes for robustness.

Digimarc for Images

Digimarc is a heavyweight in the industry,
offering content protection for various types
of digital media. Digimarc for Images creates
digital watermarks for image files and requires
either Photoshop orPhotoshop Elements as its

host application. Digimarc is only available as

a plug-in, although there is free reader

software available for the Windows platform,

which adds appropriate functionality to

Windows Explorer and Internet Explorer.

Equivalent software is not yet available for

Mac. The freeware is fine for trying out the

Digimarc functionality, but you can only

actually apply unique working watermarks

if you take out a paid subscription to the

service. These start at US$50 per year, and the

crawler service costs the same again. The

price brackets vary according to the number

of images you want to track, so if

you have a large collection of online photos,

it can get quite expensive to keep an eye on

them all.

In the past, Digimarc used the same basic

luminance-based technology to watermark

RGB and grayscale images, although this

method can produce unwanted image

artifacts. In 2010, the company introduced its

new ‘Chroma’ technology, which uses

changes in color data to watermark images.

These changes are much more subtle and less

likely to create unwanted artifacts. Chroma is

Invisible Watermarks | Tool Test

Today’s watermarks are often extremely

robust and cause irreparable damage

to the carrier image if you attempt to

remove them. This is certainly true of

the products offered by market leader

Digimarc and, at normal magnifications,

any reduction in image quality for

everyday subjects is pretty well negligible.

Additional noise is, of course, not

especially desirable in a digital image but,

among all the other imperfections that

plague our photos (such as chromatic

aberrations or sensor noise), a watermark

can usually be well hidden without

producing critical changes to the look of

an image. It is more difficult to hide

watermarks in digitally created graphics,

which tend to have a super-clean look in

the first place. The high-resolution sample

images included on this issue’s free DVD

include watermarks created by both of

our test programs so you can see for

yourself whether you think they make a

difference.

Watermarks and Image Quality – Sample Images on DVD

Instead of using the entire frame, SignMyImage embeds its watermarks in selected image areas