The characteristics and the incidence of changes in plain chest radiographs were analysed in detail in 50 asthmatic patients with chronic allergic bronchopulmonary aspergillosis in whom the diagnosis had been made from 2 to 25 years previously (mean duration 10-9 years). One thousand two hundred and forty-two chest radiographs, an average of about two per year per patient, were reviewed. Two hu...

When humans perceive the lightness of an object's surface in shadows there is an implicit assumption that cast shadows dim the surface. In two experiments, we investigated whether 5- to 8-month-old infants make this assumption about shadows. According to this shadow assumption, the apparent change in lightness produced by shadows on an object's surface are attributed to blocked light sources. I...

Detecting objects under the influence of shadows is a difficult in computer vision. Shadows acts as barrier in correcting feature extraction of image features like buildings, towers etc. In urban regions, shadows cause artificial color nature and shape deformation of objects, which degrades the quality of images. In apparent path detection application, strong shadows on the road troubles the de...

Recently, psychologists have turned their attention to the study of cast shadows and demonstrated that the human perceptual system values information from shadows very highly in the perception of spatial qualities, sometimes to the detriment of other cues. However with some notable and recent exceptions, computer vision systems treat cast shadows not as signal but as noise. This paper provides ...

Many existing computer vision modules assume that shadows in an image have been accounted for prior to their application. In spite of this, relatively little work has been done on recognizing shadows or on recognizing a single surface material when directly lit and in shadow. This is in part because shadows cannot be infallible recognized until a scene's lighting and geometry are known. However...

In this study of the informativeness of shadows for the perception of object shape, observers viewed shadows cast by a set of natural solid objects and were required to discriminate between them. In some conditions the objects underwent rotation in depth while in other conditions they remained stationary, thus producing both deforming and static shadows. The orientation of the light source cast...