Technology
Everything happens on the phone.
Naming an animal should be instant, work without a signal, and cost nothing per photograph. That rules out sending pictures to a server, so Pawdex does the whole job on the device instead.
Finding the animal
A detector first locates animals in the frame and separates them from people, vehicles, and empty scenery. This matters more than it sounds: photographs of wildlife are full of distractions, and glass at an aquarium can put a whole reflected crowd behind the subject. A confident animal is never discarded because a person happens to be standing nearby.
Naming the species
Most classifiers can only answer with labels they were trained on, which caps them at a few hundred or a few thousand species. Pawdex instead compares a photograph against a precomputed description of every taxon it knows, so its vocabulary is a data file rather than a fixed output layer. That is what makes 85,825 species affordable on a phone, and why the list can grow without retraining anything.
Several classifiers are consulted together. A broad, open-ended one gives reach; narrower ones are better on the animals they were built for. Where they disagree, the more specific answer only wins if it is genuinely more convincing.
Knowing when it does not know
Confidence is measured as how far the best answer stands clear of its rivals, not by how close the match looks in absolute terms. A blurred photograph sits about equally far from thousands of species at once, and treating that as certainty is how apps confidently name the wrong animal. Pawdex would rather ask for a clearer view.
When it is still wrong, you can correct it and choose from every species it knows. The correction is remembered against what the model saw, so the same animal in the same place is recognised next time.
Telling individuals apart
Species is only half the story. A short burst of frames is condensed into a numeric signature — a list of numbers, not a picture — and comparing signatures lets Pawdex recognise one particular animal across visits, from slightly different angles. The footage itself is discarded.
Vision has limits here that honesty requires admitting: an animal that has grown over a year may not match its earlier signature. When you know it is the same creature, you can say so, and your word takes precedence.
Keeping the numbers honest
A card's measurements are drawn from cited references, and each figure records whether it was measured for that species or estimated from its close relatives. Rarity is not a game designer's invention: it follows IUCN Red List conservation status, so the rarest cards belong to the animals genuinely closest to disappearing.