We present an algorithm for separating the shading and reflectance images of photographed natural scenes. The algorithm exploits the constraint that in natural scenes chromatic and luminance variations that are co-aligned mainly arise from changes in surface reflectance, whereas near-pure luminance variations mainly arise from shading and shadows. The novel aspect of the algorithm is the initia...

This article presents the results of an assessment of radiometric correction methods of images taken by the large-format aerial, photogrammetric, multispectral pushbroom camera Leica Geosystems ADS40. The investigation was carried out in the context of the multi-site EuroSDR project “Radiometric aspects of digital photogrammetric images”. Images were collected at the forestry research test site...

The reflectance map used by the visual system for perception of shape from shading was estimated. In Experiment 1, an image of a cylinder or a sphere illuminated from the viewer's direction was presented, and subjects estimated the cross-section of perceived 3D-shape. The reflectance map was estimated from the relationship between the stimulus image intensities and the slants of the measured cr...

The spectral reflectance and transmittance over the wavelength range of 250–700 nm were evaluated for leaves of 20 deciduous tree species and leaf sheaths of five isogenic wax variants of Sorghum bicolor differing in visible reflectance due to cuticular waxes. Using the sorghum sheath reflectance and cuticle surface characteristics as a model, it was concluded that tree leaf reflectance above 0...

The extreme ultraviolet (EUV) reflectance of amorphous tetrahedrally coordinated carbon films (ta-C) prepared by filtered cathodic vacuum arc was measured in the 30-188-nm range at near normal incidence. The measured reflectance of films grown with average ion energies in the ~70-140-eV range was significantly larger than the reflectance of a C film grown with average ion energy of ~20 eV and o...

Reflectance and shape are two important components in visually perceiving the real world. Inferring the reflectance and shape of an object through cameras is a fundamental research topic in the field of computer vision. While three-dimensional shape recovery is pervasive with varieties of approaches and practical applications, reflectance recovery has only emerged recently. Reflectance recovery...

The variation among faces can be partitioned into two sources: (a) shape and (b) surface reflectance. To compare the utility of shape and reflectance for face recognition, we created two sets of faces, with individual exemplars differing only by shape in one set and only by reflectance in the other set. Grayscale and full color versions of the stimuli were used in separate experiments; the phys...

The wing-scale morphologies of the pierid butterflies Pieris rapae (small white) and Delias nigrina (common jezabel), and the heliconine Heliconius melpomene are compared and related to the wing-reflectance spectra. Light scattering at the wing scales determines the wing reflectance, but when the scales contain an absorbing pigment, reflectance is suppressed in the absorption wavelength range o...

his study demonstrates the feasibility of coastal water quality mapping using satellite remote sensing images. Water quality sampling campaigns were conducted over a coastal area in northern Taiwan for measurements of three water quality variables including Secchi disk depth, turbidity, and total suspended solids. SPOT satellite images nearly concurrent with the water quality sampling campaigns...

A radiometric system, deployed from a ship, is used to measure directly the influence of the presence of breaking waves (whitecaps) on the upwelling radiance above the sea surface. Estimates of their remote sensing augmented spectral reflectance, i.e., the temporally averaged or spatially averaged increase in the ocean’s reflectance over and above the reflectance in the absence of breaking wave...