I kind of figured it was complex, but not THIS complex. Would you by any chance have a link to a research paper - Though I highly doubt it ;) - that would have something like this in it.
Does anyone think that there is some open-source way to accomplish it? Sincerely, Pierce F. On 10/30/08 10:04 PM, "Graham Cox" <[EMAIL PROTECTED]> wrote: > > On 31 Oct 2008, at 2:21 pm, Pierce Freeman wrote: > >> Hi everyone. I am wondering if there is some way to compare two >> images in >> Cocoa, and then somehow spit out a percent of how similar they are. >> The only >> way I could think of is comparing every pixel, but this seems like >> it would >> take a long time, and even so I have no idea how to go about doing >> that. > > > It's non-trivial. Comparing each pixel doesn't really work. You could > have two identical images but if one was shifted by just 1 pixel, > you'd have almost no match even though to the eye they'd look the > same. You can compare images for equality this way, but not similarity > (i.e. if they are absolutely identical in every way you can tell, but > the smallest difference means no match at all). > > Researchers have been looking into this sort of thing for years. There > are ways to do it, but it requires some pretty heavy lifting in terms > of breaking down an image into "features" then finding whether those > same features can be found in the second image, regardless of how > those features might have been transformed in size, position or angle. > You can then come up with a figure for the number of feature matches > and how these are different, and so arrive at a figure for the overall > similarity of the two images. So, it can be done but you'll need to > look at some serious academic papers to get a flavour for what's > involved - it's almost verging on AI. > > Good luck ;-) > > cheers, Graham > > _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
