Anders Wikström

Photo of digital signage for SL

SL — digital signage

SL (Storstockholms Lokaltrafik) is the public transport organisation responsible for managing public transport in Stockholm County, Sweden. Familjen had previously developed an award-winning wayfinding system for SL. But adapting this system for digital signage proved a real challenge.

The screens are extremely bright in order to be legible even on a bright, sunny day. But that comes with a downside: the screens have low resolution and, exacerbating the problem, the pixels can get a blurry "halo effect".

To ensure high legibility, the fonts, pictograms, logos and other graphics needed to be adapted to the pixel grid. Everything needed to be as sharp as possible while keeping the appearance as close as possible to the non-digital signage in SL’s wayfinding system.

Somewhat surprisingly to me, it also turned out that using anti-aliasing made type and graphics blurry, in a way that doesn’t happen with normal screens. So everything had to be made without anti-aliasing, in a way reminiscent of old school computer graphics, although the purpose in this case was purely functional rather than going for a retro look.

In addition, we needed to adapt the color values, since the normal color values were perceived as far too bright on these powerful screens.

Measurements in pixels for a sign in the subway
Measurements in pixels for a sign in the subway.
Three versions of a number for a subway line: first, how it looks in non-digital signage, second, how it looks in digital signage without adaptation for low resolution, and third, how it looks in digital signage adapted to low resolution.
Three versions of a number for a subway line:
1. how it looks in non-digital signage,
2. how it looks in digital signage without adaptation for low resolution, and
3. how it looks in digital signage adapted to low resolution.
Photo of digital signage for SL Photo of digital signage for SL