THERE'S a hitch in Google's plan to digitise the world's books and make them searchable online: scanning them is taking too long.
That's because character recognition software needs a neat 2D image of the text. But book bindings cause pages to arch up either side of the spine - bending text and making it hard to interpret.
However, last week Google was granted a patent (US 7508978) on an answer to this problem. Its trick is to project an infrared pattern onto the open page spread. This lets a pair of infrared cameras map the three-dimensional shape of the pages by detecting distortion to the pattern. This in turn allows the distortion of the text to be determined - and therefore the degree of correction needed to read it accurately.