Any resemblance is very subtle
Google has launched a new image function, which means people can look for pictures that the search engine thinks are similar. How accurate is it? The Magazine puts it to the test.
Pictures of famous people who look alike generate thousands of viral e-mails and much merriment is had between friends at the expense of Footballer X and Minister Y's wife.
Now Google is developing a modification to its image search that matches pictures of anything - person, item, scene - to others that are visually similar.
"It can be hard to find images you're looking for because it's hard to describe with words," says a Google spokesman.
"This uses a mixture of everything. Words are in there, plus the technology that analyses part of an image and compares that to other parts of images. There are many variables that go into it, like colour and shape.
"People are used to searching what they are looking for with text but this is essentially saying you can't describe it but you know when you see it."
The tool is still being developed but feedback is welcome
Analysing pictures is a lot more complex than analysing text, he adds, and in the future it may be possible to apply the same principle to moving pictures. So for example, you could search for "dog" and find all the videos that feature a dog.
The Magazine decided to put this "work in progress" image comparison to the test by seeing which pictures it throws up for three well known people, real and fictitious.
First, the distinctive face of John Prescott.
Similar Images tool
is still in the developmental stage so you will only find it via Google Labs.
The Google Images search finds hundreds of pictures of the former deputy prime minister. Only some of them have the new "similar images" link below them.
We pick one of him wearing that characteristically furrowed brow, click on the link and
see what it throws up
Sixteen Renee Zellwegers and two John Prescotts. Does this mean Renee looks eight times more like Prezza than he does?
The second page of Prescott results is still very Zellweger-heavy and the following pages throw in the odd curveball picture like Britney Spears, Colin Firth (the Bridget Jones connection?) and author Joanne Zellweger.
That last surname would indicate the influence of words in the search, although why the leap from John Prescott to Renee Zellweger? Are there any visual similarities in the original picture of him and the 16 of her?
They are all head and shoulder shots, so the proportions of the subject are more or less the same.
And Prescott is wearing a black jacket, while Zellweger in some of the images is wearing a black dress.
But he has dark hair, she has blonde. In many of the shots, her face is a lot smaller than his. She reveals her bare shoulders in some of them. He does not.
And what about the other two Prescott pictures? One of the two is an identical picture to the original, so full marks there, but the other has the former deputy prime minister with a doughnut in his mouth.
Interestingly, a "similar image" search on one of these Renee Zellweger images does not take you to John Prescott. It only goes one way.
In response to the strange Prescott-Zellweger match, Google says the tool is bound to make mistakes because it is still being worked on, but it will improve.
The second search is of Princess Leia from Star Wars, as played by Carrie Fisher, and here
the results have more visual clues
In the original image, Leia's is pointing a gun upwards while holding it to her chest.
And among the results on the first page, nearly half are of well-groomed pet dogs with no apparent link to Star Wars.
Two of the dogs have Princess Leia-style hair buns and there are also two pictures of youngsters doing impressions of her, so that could be a very loose resemblance. But it could also be that word association was again a factor.
A more advanced function of the new tool is that you can narrow the search according to colour, so you can just search for images of Princess Leia which have the colour red in them, and this works very well.
Or you can just search for certain kinds of content, like pictures of her that are from the news, or just line drawings of her or just faces.
In the last of our three searches, we'll give you a teaser. If we search for similar images of England manager Fabio Capello, who do you think shows up?
Click on the enlarged image (above) on the right to find out.
And when you've seen the answer, you can
look here to see the first page of results
Here is a selection of your image matches using Google's new tool.
David Cameron and The Prodigy's Keith Flint - who'd have thought, eh?
Jake Perks, Shropshire, UK
Anthony Worrall Thompson = Melinda Messenger (!)
Apparently David Beckham with long hair is a close match to Jennifer Aniston.
Chris Spinks, London
David Hasselhoff IS the lost son of Tom Jones. I'm going to have hours of wasted fun with this, great invention Google - hilarious if not particularly spot on!
Debbie La, London, England
This is a brilliant way to waste time in bored moments. Adrian Chiles from The One Show who apparently is a car.
Laura Hamer, Cheltenham
For no reason at all, I looked up Margaret Thatcher. Imagine my surprise when Michael Douglas is the "similar image".
Duncan Smith, London
Just searched for Margaret Thatcher, chose an image and clicked for similar ones - Madonna came up - can't stop laughing, this is a great way to brighten a morning. Three pics of Thatcher and the rest of the page Madonna - bet her Madge-ness won't be impressed.
Kathryn Cresswell, Pafos, Cyprus
It appears that Tottenham captain Ledley King looks like a duck.
Apparently Queen Elizabeth II looks just like Faisal Qaragholi of the Iraqi National Congress (never even mind the moustache).
Justin, Hull, UK
The algorithms need some work. Steven Gerrard, the Liverpool football genius, is a dead ringer for singer Robin Thicke - to look at them you'd think they'd been separated at birth. Both have 100s of pictures searchable via Google Images but this so-called similar image engine didn't seem to make the connection at all.
Alvin Shillingford, London, UK
My favourite is that the BBC news graphic logo links to lots of posters for Willie Wonka and the Chocolate Factory. In second place Farah Fawcett appears similar to two fried eggs.
Victoria Wood produces lots of pics of Victoria Beckham.
Kevin P, Reading
Prescott and Zellweger appear to have very similar noses, so perhaps Google is picking up on that.
John Prescott also throws up a large number of images of Hazel Blears, plus an odd one of a man wearing nothing but yellow hazard tape.
I was intrigued to see that Piers Morgan is "like" Jeremy Clarkson. Clearly the Google tool is cleverer than we thought - it also matches on personality and annoyance factor...
When I first tried it on images for Barack Obama it brought up a photo of the mastermind behind the 9/11 attacks; Mohammed Atta. Looks like they've fixed that now.
Matt Whitby, Thatcham, Berkshier
Pictures of John Cleese result in pictures of Bollywood actress Aishwarya Rai.
Matite Petchotte, Lille, France
Leona Lewis shows as a match for Boris Johnson, and a monkey for Ken Livingstone.
This article shows a complete misunderstanding of how this technology works. When you give Google the source picture all the computer "sees" is a grid matrix of squares shaded with light from the red, green and spectrums, that's it. When you give it a picture of John Prescott the computer doesn't see Prescott's jowly face or Renee's blonde hair, it just sees a grid of squares. The patterns in Prescott's grid are obviously just similar to the patterns in Renee's. It doesn't mean the computer is trying to suggest the two people look alike, just that the code that makes up those images shares some similar numerical patterns.
James Wilde, Newport Pagnell