Automatically detect contours

kfroese

Could it be possible to build on the "Create Area features from Equal Values" to create lines following raster contours? Seems like it might be possible to click on a contour line and have GM trace it out based on a contrast in pixel colour between the contour line and other stuff on the raster. Ideally, it would pick the middle of the line based on the average distance to the contrasting edge between either side.
I'm requesting this as I have a map that seems to require a large range in colour fuzziness to identify the contours (it's a low-res image). I think that looking a sharp contrast could be simpler.