1. A method for detecting roads in an aerial image of ground topology, comprising: determining low-level features for each pixel in an aerial image of ground topology; determining middle-level features for each pixel from the low-level features; placing a first window over each pixel, the first window including adjacent pixels to each pixel; determining high-level features for all of the pixels in the first window from the middle-level features of all of the pixels in the first window; and assigning a single probability to each pixel based on the high-level features, the single probability indicating a likelihood that the pixel is associated with a road.