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#1
hsn22

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hey,

im new to the GIS community, and have been reading up a lot. but have been unable to find a solution for my problem.
its quite simply this: i have a bunch of street maps which i have to put online. from what ive read, i know i have to
1. georefernece them
2. create shapefiles
3. create mapfiles and put them on mapserver

while i realise im making it sound simple, i do know the enormity of the task ahead.
my question is this though: because i have a bunch of maps, do i have to *stitch* them together or is it enough to georeference them and mapserver will understand that?
i did read something somewhere which said i could combine these multiple shapefiles into one. is that an efficient way to go?

i know i might sound silly with these questions, but im just a novice, so thanks for bearing me.

#2
Hans van der Maarel

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my question is this though: because i have a bunch of maps, do i have to *stitch* them together or is it enough to georeference them and mapserver will understand that?
i did read something somewhere which said i could combine these multiple shapefiles into one. is that an efficient way to go?

i know i might sound silly with these questions, but im just a novice, so thanks for bearing me.


Okay, first of all, a scanned image is a raster file, whereas shapefiles are vector files. In other words, there is no quick easy way to go from a scanned image to a shapefile.

If you have multiple scanned maps that you've georeferenced, a map-server should be able to display them as-is. However, for ease of use, I'd recommend mosaicking them anyway.
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#3
hsn22

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my question is this though: because i have a bunch of maps, do i have to *stitch* them together or is it enough to georeference them and mapserver will understand that?
i did read something somewhere which said i could combine these multiple shapefiles into one. is that an efficient way to go?

i know i might sound silly with these questions, but im just a novice, so thanks for bearing me.


Okay, first of all, a scanned image is a raster file, whereas shapefiles are vector files. In other words, there is no quick easy way to go from a scanned image to a shapefile.

If you have multiple scanned maps that you've georeferenced, a map-server should be able to display them as-is. However, for ease of use, I'd recommend mosaicking them anyway.


Hans,

thanks for the reply. i do know the steps in going from a raster scanned image to a shapefile. what my confusion is regarding is whether converting individual files to shapefiles is enough to make mapserver understand that they cover whatever (large) area. as i am not a native english speaker, i realise i might not be making complete sense, so let me break it down:

i take one scanned file, create a shapefile from it. (lets say all the lines)
i take the next scanned file, create another shapefile from it. (again, all the lines)

if i put these two shapefiles on mapserver, will mapserver understand that the lines are near each other and render them so.
or will i need to merge the shapefiles to make it understand.
or do i need to merge the maps before creating the shapefiles so that it'll understand.
or, and this seems more likely to me, does it use the coordinates (that i specified while georeferencing the scans) to understand this fact. and i believe this is the point you were trying to make.

mosaicking? thats the first ive heard of it. any resources you might be able to point me to?

thanks for taking the time to reply. i apologise if my question is inane, but i'd like to make sure that what im about to do is the right way and i wont have to backtrack and re do all the work.

#4
aug_aug

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I don't have much experience with Mapserver, but I would guess that you would want to mosaic them as mentioned above, resulting in one large shapefile. I would think that lots of stacked shapefiles and Mapserver would not work well together in areas where one map overlaps another.

As mentioned above you probably want to keep the shapefile as clean/easy to manage as possible, easy to manage, I would merge.

#5
hsn22

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I don't have much experience with Mapserver, but I would guess that you would want to mosaic them as mentioned above, resulting in one large shapefile. I would think that lots of stacked shapefiles and Mapserver would not work well together in areas where one map overlaps another.

As mentioned above you probably want to keep the shapefile as clean/easy to manage as possible, easy to manage, I would merge.


hey Michael,

are you suggesting i create individual shapefiles for each scanned image and then merge them? the problem, as i'm seeing it, is that there are features (like roads) that originate in one imaeg and extend all the way into the next image. would mapserver understand that the separate segments are part of the same road?

thanks.




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