Texture is one of the important characteristics used in identifying objects or regions of interest in an image, whether the image be a photomicrograph, an aerial photograph, or a satellite image. This paper describes some easily computable textural features based on graytone spatial dependancies, and illustrates their application in categoryidentification tasks of three different kinds of image...

The liansition to formal mathematical thinking involves the use of quantified statements as definitions from which fmther properties are consliucted by formal deduction Om quest in this article is to consider how students construct meaning for these quantified statements. Dubinsky and his colleagues (Dubinsky et al, 1988) suggest that the process occms through reflective abstraction, in which a...

We have developed a prototype system in which a user can fuse up to 4 modalities (or 4 spectral bands) of imagery previously registered to one another with respect to a 3D terrain model. The color fused imagery can be draped onto the terrain to support interactive 3D flythrough. The fused imagery, and its opponent-sensor contrasts, can be further processed to yield extended boundary contours an...

In contrast to earlier satellites with SAR instruments, the ENVISAT and ALOS platforms provide state vectors and timing with higher relative and absolute accuracy, allowing the ASAR and PALSAR sensors to directly support accurate tiepoint-free geolocation of their imagery. This enables not only direct map overlays with other sources, but also normalisation for the systematic influence of terrai...

Human perception of an image's conspicuity depends on the stimulus itself and the observer's semantic interpretation. We investigated the relative contribution of the former, sensory-driven, component. Participants viewed sequences of images from five different classes-fractals, overhead satellite imagery, grayscale and colored natural scenes, and magazine covers-and graded each numerically acc...

Orthophoto imagery is a very beneficial layer in a GIS as it provides a generic, inexpensive, and accurate base map. However, in cities with tall buildings, the creation of a seamless database of orthophoto imagery is difficult. Traditional methods for orthophoto rectification do not consider buildings. Therefore, features at street level are hidden due to building lean. Using a GIS to overlay ...

Calibrated airborne multispectral imagery has been used to retrieve and map biophysical parameters, specifically biomass, in a rice crop (Oryza sativa). Considerable amounts of image preprocessing, including correcting for image shear, camera misalignment and geometric and radiometric distortion was required. Conversion of image pixel digital numbers (DNs) to ground reflectance (R) was also nec...

We reanalyzed data reported in previous mental imagery experiments (D’Angiulli, 2001; D’Angiulli & Reeves, 2002). The data consisted of self-reported image vividness ratings (1 = no image; 7 = perfectly vivid) and image latencies (image completion RTs) for “small” (i.e., subtending < 16) and “large” (i.e., > 16) images, in two image generation conditions: trial-unique and repeated. In the origi...