STEP 5 - Spatial enhancement
   

To improve the visibility of fine detail even further, the image is “sharpened” by applying a spatial filter. This filter works by locally boosting the contrast around the edges of features to make them stand out. On the top is the unfiltered image; on the bottom, the same area after the edge enhancement filter has been applied. This is particularly useful for enhancing human infrastructure, and is typically the final processing step.