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Finding exact coordinates of a map fragment  RSS feed

 
Lurie Williamson
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So this is a theoretical question and I intend to modify what ever responses I get to use with image manipulation.

Lets say I have Map A which is a small portion of Map B,  or if you like Image A being a sub-image of Image B.
Map A or Image A have been modified, new roads have been drawn in on Map A or additional doodles have been added to Image A.
Now Map B and Image B never change and are the same always.
Map A and Image A on the other hand are random sub portions of their larger counter parts.
I have no way of knowing where the sub-image or map fragment top right corner are but they are always oriented in the same way (original and fragment).
I need to find the top right of the sub image/fragment by comparing it to the original.
My thought is to use highways or things that do not change and overlay it with an error percentage, but i do not know how accurate that would be given that if additional highways were drawn or similar doodles  there might be either a false positive or too much difference to be positive. Thoughts?
 
Campbell Ritchie
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Welcome to the Ranch

Maybe: Find a map online and an older version of the same map, and print both on paper. Cut a piece out of one and see what criteria you would use to match the two on paper.
That sounds like an awkward problem, so have you searched for algorithms and criteria for such matching? Do maps have writing on? Is it recorded as text or graphics?
 
Lurie Williamson
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Its all recorded as graphics, Im trying my best to do it all via program with as little human interaction as i can. The problem I am running in to is how to make the program recognize the key points in the original map by comparing it to the fragment without the extra drawn in parts causing problems.
 
It is sorta covered in the JavaRanch Style Guide.
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