botmer

Batch checking for raster and vector matching

Discussion created by botmer on Jan 31, 2013
Hello,

I have this issue. We have a large set of topographic maps as rasters, and each raster has its corresponding set of themes as vectors (eg. rivers, roads, contour lines, etc).
We needed to have the whole set of rasters and vectors in 2 different datums, NAD27 and WGS84. So we automated the reprojection with python scripts and got the whole sets.

Now, we want to check that the vectors match their corresponding raster. I took randomly several maps from the set, and opened individually the raster to overlay with the vector. In most cases, the correspondence was OK, but I found a few rasters that were hundreds of meters away from their corresponding vector (e.g. the vector contour lines don't fall right over the raster's contour line).

So the issue is, it's a gruesome task to open each raster (there's over 2000) and each vector to check if the reprojection went all right or if the raster came originally with errors in georeferencing.  I must say that Arcmap is not the best tool for doing this, as it slows down and hangs when loading a few dozen rasters and their vectors.  I use another program for this. In most cases, I would say the raster came originally wrong in the projection/georeferencing. I would like to have a list of these cases.
It would be much easier if there were a tool, python scripting ideas or something that could help automate checking the raster -vector matching, without having to open each of the 2000+ tiffs and overlay the vectors.
I would appreciate any ideas for performing this task faster. Thanks.

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