aprs.fi high-resolution symbol set
This is a new APRS symbol graphics set, which can be used by any APRS applications, for free. I've assembled it in an effort to make aprs.fi look better on modern high-resolution displays, including Retina and 4K displays. It is released to the APRS community on 2015-12-03 to celebrate the release of the aprs.fi iPhone/iPad app.
The new symbols are drawn in vector format (as opposed to a raster format at a fixed resolution), allowing them to be rendered at larger and smaller sizes without distortion or blurriness. The new symbols are slightly larger than the old ones, making them easier to recognise on modern displays having smaller pixels than the old ones. They can be rendered in high resolution so that they're properly sharp on the 4K/retina displays found on many modern tablets, phones and computers!
The PNG files contain an alpha layer, which is used in many symbols for (partial) transparency. Make sure that is handled when using the PNGs.
Most symbols in the PNGs contain a little bit more unused space around the actual symbol, than in the old symbol sets. The amount of space also varies slightly too much to my taste. I will probably work on that later on.
File naming, table identifiers:
- aprs-symbols-SIZE-0.png: Primary table
- aprs-symbols-SIZE-1.png: Secondary table
- aprs-symbols-SIZE-2.png: Overlay characters
File naming, sizes (follows iOS naming convention):
- aprs-symbols-24-TABLEID.png: 24x24 pixels/symbol
- aprs-symbols-24-TABLEID@2x.png: 48x48 pixels/symbol
- aprs-symbols-64-TABLEID.png: 64x64 pixels/symbol
- aprs-symbols-64-TABLEID@2x.png: 128x128 pixels/symbol
Naturally I did not draw all of the symbols myself. Many are loosely or strongly based on the original symbol graphics, primarily to keep the familiar and consistent look. Some symbols I obtained from other sources, such as Wikipedia. In those cases I picked SVG versions which allow commercial reuse (source known, and the work is placed on public domain, or with a CC license which allows adaptation and commercial reuse). In any case, the source and copyright information is documented separately for each symbol (see COPYRIGHT).
If you use this symbol set, please provide a pointer to the source (http://github.com/hessu/aprs-symbols/).
The aprs.fi symbol graphics set does not contain additional symbols for overlays yet, mostly because it takes lots and lots of time to draw them, and the effort it took to create this set was pretty high already. Maybe later!
Differences to original set
The symbol set should be generally compatible with the Updated APRS Symbol Set (Rev H).
There is one obvious difference in the new symbol set: the "ham store" symbol has been replaced with a more generic "store" shopping cart, reflecting the current \h symbol definition in the master index. Please use the 'H' overlay character to specify an amateur radio shop.
To complement the symbol graphics, I've previously published a machine-readable (CSV/JSON/XML/YAML) APRS symbol description index, which is easier to integrate in applications than Bob's master list.
There will be some updates to this set. If you use it, please be prepared to update the images from the master files.
APRS symbols are not transmitted over the radio, or over the APRS-IS, as small images. A two-character code is transmitted, which guides the receiving softare to display one of the symbols installed locally at that end.
We can not make everyone see new symbols by just adding graphics here. Everyone in the network need to update their symbol graphics files to see new ones. So, please do not suggest adding completely new symbols to this file. It just does not work like that.
Heikki Hannikainen OH7LZB