Google has released research results about a new test to foil computers pretending to be humans by requiring them to orient an image so it's upright. The test is the latest variation on a screening technique called a Captcha (completely automated public Turing test to tell computers and humans apart). The idea is that people can often tell which way is up in a photo, but computers have a harder time. “This task requires analysis of the often complex contents of an image, a task which humans usually perform well and machines generally do not,” describe Google in their image-orientation technique paper.

Source:→ CNet