On Tue, Mar 1, 2011 at 11:15 AM, Kieren Diment <dim...@gmail.com> wrote: > > On 01/03/2011, at 10:05 PM, Christopher Jones wrote: > >> On 1 March 2011 09:49, Dave Cross <d...@dave.org.uk> wrote: >>> >>> Need some advice on iPhone Barcode reading apps - so I turn to london.pm, my >>> favourite group of iGeeks. >>> >>> My wife is a teacher and they're about to start a stocktake of all of the >>> books in the English department. Rather than count them all, she wondered if >>> there was an iPhone app that could help them. >> >> >> I'm fascinated to know how you could use an iPhone to scan a barcode - can >> someone explain? > > With the camera ;) Scanning high contrast images for information is a > reasonably well solved problem. Get rid of noise and highlight edges with a > LoG (laplacian of gaussian filter - could be wrong here my knowledge is > ancient and theoretical), then seeing as a barcode is basically a 2d image, > use the barcode spec to get the information out of it by walking along the > line measuring the thickness of the bars.
There's a rather nice worked example of implementing barcode scanning in 'Real World Haskell'.
