In one embodiment, a plurality of target pixels within a digital representation of an image are selected, and a corner gradient pattern is determined for each of the target pixels. The corner gradient pattern is analyzed to classify the target pixel as an edge pixel or a non-edge pixel. If the target pixel is a non-edge pixel, target pixel is replaced with a plurality of non-edge output pixels. If the target pixel is an edge pixel, the target pixel is replaced with a plurality of edge output pixels, including determination of an orientation of an edge, and selection, based on the orientation, and application of a filter kernel to produce the edge output pixels to replace the target pixel.