Recovering Intrinsic Scene Characteristics From Images

Abstract

We suggest that an appropriate role of early visual processing is to describe a scene in terms of intrinsic (veridical) characteristics – such as range, orientation, reflectance, and incident illumination – of the surface element visible at each point in the image. Support for this idea comes from three sources: the obvious utility of intrinsic characteristics for higher-level scene analysis; the apparent ability of humans, to determine these characteristics, regardless of viewing conditions or familiarity with the scene, and a theoretical argument, that such a description is obtainable, by a non-cognitive and non-purposive process, at least, for simple scene domains. The central problem in recovering intrinsic scene characteristics is that the information is confounded in the original light-intensity image: a single intensity value encodes all of the characteristics of the corresponding scene point. Recovery depends on exploiting constraints, derived from assumptions about the nature of the scene and the physics of the imaging process.