An example: Interpreting a line drawing

3-D lines

• Use one “2-D line” unit for each possible line in the picture. – Any particular picture will only activate a very small subset of the line units. • Use one “3-D line” unit for each possible 3-D line in the scene. – Each 2-D line unit could be the projection of many possible 3-D lines. Make these 3-D lines compete. • Make 3-D lines support each other if they join in 3-D. Make them strongly support each other if they join at right angles.

2-D lines

picture