Bi-partitioning and boundary detection in natural scenes.

We propose a strategy for early vision which tailors visual channels to the object-oriented characteristics of natural scenes. This strategy involves essentially two types of channel, one for encoding the locally dominant edges which form the boundaries of 'objects', and another for 'filling in' the regions within them. The selection of contrasts which characterize object boundaries rather than textural detail can be enhanced by making an estimate local of contrast, and setting a threshold accordingly. This procedure and other aspects of the model were first suggested by observations of insect visual cells.