The Core

last week, image host Flickr launched Park or Bird, a website designed to solve the exact problem in the comic. Just drag a photograph into the page, and it will make an educated guess. Gerry Pesavento, senior director of product management at Yahoo in San Francisco, which owns Flickr, says the site doubles as a playful introduction to a genuine problem.

Google made waves two years ago with the announcement that it had trained neural networks to spot cats in YouTube videos. Chinese search giant Baidu is also in on the game, offering a translation app that tries to provide the right English word for whatever you have taken a picture of. Amazon's Fire phone comes with a feature that recognises the front covers of books or CDs in the real world and directs you to the relevant shopping website.

Olga Russakovsky at Stanford University in California co-organises the ImageNet Large Scale Visual Recognition Challenge, an annual competition with 1000 categories of objects to identify. In the four years since the challenge began, the quality of the entries has improved remarkably quickly. The winner in 2010 made mistakes 28.2 per cent of the time. Last year's Google-led winning program had an error rate of only 6.7 per cent – only a smidge behind an actual human annotator.