Extra-terrestrial image problem

I’ve always been a little bit sceptical of folks who claim to have seen flying saucers from other worlds. After all, if life does exist on any planet even a few light years from our own, it’s highly unlikely that the ’folks’ there would be able to travel to the Earth in their own lifetime without playing some very clever tricks with the very fabric of space time.

But last week I had cause to reconsider my position when a friend phoned to say that she had seen ’some very fast-moving objects in the sky’. Not only that, but she had captured a picture of one of them using her digital camera. And the image, she believed, would prove without a doubt the existence of extra-terrestrial life!

When she showed me the image on the camera’s small LCD viewing screen I was astonished - for there was what appeared to be a huge circular object surrounded by a brilliant white light. It looked exactly like the flying saucers that I had read about in the science-fiction books of my youth.

The strange photograph prompted me to rush to the Internet to perform some research into the subject. Knowing that there’s a lot of top-secret stuff going on into the development of futuristic aerospace systems, I decided to see if I could find any evidence that the clever folks at NASA, Grumman Aerospace or Boeing might be developing such aflying object.

Unfortunately, I couldn’t find any. What I did discover was that a number of companies have indeed created vehicles that resemble flying saucers over the years. But while some of them have even been produced in limited quantities, none of them appeared to be advanced enough to hover over a small English town on a Saturday night.

So having no idea what the mysterious object could be, my friend and I decided to print the image from the camera onto some photographic film so that we could examine it in a little more detail. Only then did we realise what it was that we were looking at.

The large silver object was nothing more than a reflection of the camera in the window. And the white light was nothing more than a reflection of the camera’s flash. Well, of course it was, wasn’t it? But you can only imagine, dear reader, how intellectually inadequate we both felt because we hadn’t realised that a lot earlier!

The whole embarrassing affair made me appreciate one important thing, though - the old saying that the camera never lies is far from accurate. The fact is that a camera is no more than a machine that can neither lie nor tell the truth - it merely captures an image. The truth is revealed only when the image is correctly interpreted, a process that, as I found out to my embarrassment, is a much more complex affair altogether and one that my buddies in the machine vision industry have known for years.

Dave Wilson
Editor, Engineeringtalk

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