Apparatus are provided, which include a color image processor, an edge
distinguisher, and an edge trapping mechanism. The color image processor
processes color images, including a given color image. The given color
image includes plural color separations each having a set of color values
for respective image pixels. The edge distinguisher distinguishes some
edges of the given color image as opposing edges. An edge is a transition
in the color separation of the given color image from a non-white color
intensity value, at one side of the edge, to a white intensity value, at
the other side of the edge. A given edge is an opposing edge when a
transition of the given edge goes, for a separation of the given color
image, in one direction from a non-white color value to a white value,
and goes, for another separation of the given color image, in the same
direction from a white value to a non-white color value.