Finding source maps
Good challenges start with a good source file — and permission to use it.
Where to look
| Source | What you get | Worth it? |
|---|---|---|
| Your club's map archive | The OCAD files themselves, for every training and event map the club has produced | By far the best. Ask the map officer. |
| The event organiser | The OCAD file or a high-resolution export for a race you just ran | Excellent, and usually granted if you ask |
| National federation map libraries | Searchable archives, often member-only | Good, though usually images rather than OCAD files |
| A printed map you scanned | An image at whatever your scanner does | Workable — see the quality notes below |
Ask for the OCAD file, not the PDF
People default to sending a PDF because it is the thing they have to hand. The OCAD file is what lets you skip the impassability generation and editing entirely, and it costs the sender nothing extra to send. It is worth one more message.
What makes a good source
- An OCAD file, if at all possible. Everything else is a compromise against it.
- Otherwise, the highest resolution you have. The impassability detection reads fine detail — a thin fence line has to survive into the image to be found.
- Faithful colours. The detection works from map colours, so a faded scan or a recoloured export shifts them and it guesses wrong.
- Not a heavily compressed JPEG. Compression artefacts eat exactly the detail that matters.
- Not a photograph of a paper map. The perspective distortion cannot be corrected by the pipeline, and everything downstream inherits it.
Permission
Most orienteering maps are somebody's copyright
The producing club owns the map. Get permission before uploading a map you did not make, and be specific about what you are asking for — a map shared privately with your own club is a different request from one published to the whole Routster community.
In practice clubs are usually happy to say yes, particularly for a map that is no longer embargoed. The conversation is short and it is the map officer's to have, not yours to assume.
If you only need it for yourself, keep the upload private. That is where every map starts, and it is the right setting for a map you have not asked about yet. See the Mapping Lab for the three sharing levels.
Next
With an OCAD file: the OCAD workflow. With an image: standard uploads.