Hi, I am interested in finding or writing a program that can read a topographical map and convert it into 3D terrain. I am interested in your thoughts or suggestions about this. Is it feasable? -GE

Hey galneweinhaw,

This should be feasable permiting you can extract the data you need from the map.

I'm not sure how data is stored for digital topographical maps. If it is just a bitmap that would make things very difficult/impossible as text and stuff like that would mess up the map. Do you have any information on how this is stored? (I wouldn't even know an extention to look up).

I'm gonna check into how the digital data is stored

It would be pretty easy to strip out the text & other lines on the map without ruining the topography too much. I'm sure you guys can come up with some creative algorithm to interpolate the map data to cover up any letters.

Quote: Original post by Luke Miklos
It would be pretty easy to strip out the text & other lines on the map without ruining the topography too much. I'm sure you guys can come up with some creative algorithm to interpolate the map data to cover up any letters.

It's not as simple as that if it is just raw color data. Topo maps arnt color depenednt on height. There are lines at each incriment of a hight. Colors are for if its forested, water, etc. So creating an algorithm that would strip text and reconize contour hight lines, is well not going to happen.

I don't care what the color stands for, whether its how many pounds of jello reside in that region or maybe economic scales... it won't matter. It would still be relatively easy to strip out the text (assuming its a known color of its own) & replace it with interpolated color values from the pixels around it. Even if it characters or symbols lie on edges of 2 or 3 or more colors... you can at least apply a hack if you don't wanna be creative & just copy the color of the closest real pixel to the one you are replacing. Would it be real? heck no... thats what interpolation is... fake, but a good guess.

All contour height lines are the same colour though... so it should be possible shouldn't it? Check this out as an example:

http://happyhikers.ca/NotQuiteCityPeople/Adventures/RohrBasin/RohrTrailMap.htm

Do you think it would be possible to extract the contour lines?

of that map? Absolutely, except its not to clear (to me, just by looking at it) whether a line means an increase or decrease in elevation. You'll have to take those funny pictures off too (tent, cabin, van).

You think so? cool.....

Now... is anyone willing to give me a hand in getting started? I don't really have a clue where to start.

Up and down don't really matter, if you're wrong you can just flip it upside down.

well, I image an algo like this:

start at top left corner, assume height of 0move across the top row    if no contour line, continue    else (there is a contour line)        Track the contour line all the way in both directions        count the number of times you've crossed this line already            if the Number is odd, height--, else height++etc.

what do you guys think?