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"Keith W" wrote in message
... wrote in message oups.com... [ SNIP ] A UAV with realtime video image recognition and IR sensors is unlikely to be especially cheap Realtime video image recognition needs a source of video (probably a wide-angle search camera + narrow angle scope with some decent magnification for examining the suspicios contacts), Problem 1 ) You have to process them to decide if they are suspicious a decent CPU to do the number crunching and a software to do the analysis. The first two items are not particularly expensive. The software might take real pains to develop, but afterwards the copies are free. Understatement of the year [ SNIP ] If he can show the image processing and recognition problem to be easy, his soon-to-be net worth will be more than that of Bill Gates. In fact, he'll hire Billy just to supervise the programming staff to write the queuing software for his executive bathroom. Despite humongous amounts of research being done over many decades, general computer vision remains an intractable problem. To illustrate, it may be impossible for a vertical photograph (satellite) to differentiate between a parking lot surrounded by a board fence and with a few cars parked on it, and a large building with a flat roof and large roof vents, both with roads nearby and under conditions of shadowing. Now, in this case we'd certainly have a rules base codifying the knowledge. But even restricting the problem to that of finding ships in the open ocean, it's still not that simple. At a typical distance and altitude, a lot of those ship lines are actually curves, so your algorithms need to recognize smooth curves as part of a ship definition. Hmmmm, what else at sea is often a fairly smooth curve? I have a photo (8 1/2 by 11") of most of 4th MEB at sea, either 1990 or 1991. Fourteen vessels (LSTs, LPDs, LSDs, LPHs, one LHA, and a hospital ship - no UNREP ships) are depicted. Going off the length of the LHA (shown at a significant oblique), my estimate (very rough) is that the formation is 5-6 km across and perhaps 3 km deep. Even compressed like this - it's a formation in time of hostilities that surely makes captains nervous - it's still a collection with lots and lots of empty space. The colour contrast and the wakes, the very calm conditions and excellent vizibility (light haze) will at least allow a decent software to identify the ships as ships. Leaving aside the hospital ship, I don't see that classifying most of the vessels in the photograph would be anything other than a [very] difficult recognition problem. A human can do it quickly, especially if cued with the knowledge that everything is a USN gator, but it would be a pretty expensive program that reliably typed each target. One wonders too if the supposedly small and cheap UAV with the purportedly inexpensive but sophisticated image recognition system is also fixing the precise 3-D attitude of the airframe and hence the camera in order to allow for estimating sizes of the objects in the picture, and _their_ attitude. Forget relying on the horizon - in my picture you can barely make it out because of haze. And it would have to be really precise data in order to get good dimensional info. What if you can't even see the wake, for one of several reasons? I'll give the program three stars if it even correctly figures out what end of the ship is which. Now let's suppose that I am somewhat harsh in my analysis. Let's say that a relatively coarse resolution picture and a basic analysis alerts the software to "blobs of interest", and then the vehicle + camera is commanded to do what it needs to do to get high-res images, and a better routine analyzes these. Given some near optimal pictures - nearly side-on to the vessel - you'd have something to work with. But in order to gauge size, you'd need to be at some moderate altitude to have good geometry, under which conditions superstructure begins to blend into the rest of the mass, not be outlined against sky. In any case, with a large, detailed image of the target, you now encounter other recognition problems e.g what details do I ignore? It is not a simple problem. AHS |
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![]() "Mark Borgerson" mborgerson.at.comcast.net wrote in message .net... In article V%qfg.6218$JX1.2803@edtnps82, says... Given traffic patterns in the Gulf, it ought to be pretty easy to test whether your software can distinguish between 1000-foot vessels and 100-foot vessels. Mark Borgerson There are LOTS of 1000 ft vessels in the gulf, most are VLCC's Keith ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
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