Due to the limitation of dynamic range, a single still image is usually insufficient to describe a high contrast scene. Fusing multi-exposure images of the same scene can produce a resulting image with details both in bright and dark regions. However, they may be sensitive to the exposure parameters of the input images. To improve the robustness of the method, a novel layered-based exposure fus...

It is generally thought that mean luminance and low spatial frequency information in a visual image are sharply attenuated at the retina, due to processes of light adaptation and the spatial filtering effects of lateral inhibition. Our results from interocular luminance masking suggest, however, that cortical masking effects play a primary role in the attenuation of low frequency sensitivity. R...

We have measured the relative perceptual scales for chromatic and luminance blur in dense textures comprised of color and luminance Gabors, using a modification of the method of paired comparisons. We find that the rate at which perceived blur grows with physical blur, when normalized to 1.0 for luminance, is 0.2 for red-green and 0.06 for blue-yellow blur. It is argued that the relatively seve...

A neural network model of brightness perception is developed to account for a wide variety of data, including the classical phenomenon of Mach bands, low- and high-contrast missing fundamental, luminance staircases, and non-linear contrast effects associated with sinusoidal waveforms. The model builds upon previous work on filling-in models that produce brightness profiles through the interacti...

Small-field color-naming performance of two protanopes over a 4-log luminance range was impoverished in comparison with that of normal trichromats, and was more strongly affected by changes in luminance. At 200 cd/m2 responses to mid-spectral lights were dominated by 'yellow'; with lowering luminance, 'green' and 'red' were increasingly used. In the color spaces derived from these data the firs...

The confusion points of dichromats are derived from the constant-luminance planes of trichromats, protanopes and deuteranopes experimentally defined by heterochromatic-flicker photometry: (1) the zero-luminance planes of the observers considered in this experiment intersect almost exactly in a line that crosses the plane of the chromaticity diagram in the tritanopic-confusion point and confirm ...

Simultaneous approaches to brightness constancy and to the perception of illumination were made in a Hsia-type experimental situation, where the immediate surround of standard disk was kept at a constant, very low luminance. 5 subjects were used. A log-log linear relation was found again between the standard luminance and the matched luminance. The obtained slopes ranged from 0.31 to 0.44. Thes...

INTRODUCTION Mobile phones hold considerable promise for delivering evidence-based smoking cessation interventions that require frequent and objective assessment of smoking status via breath carbon monoxide (Breath CO) measurement. However, there are currently no commercially available mobile-phone-based Breath CO meters. We developed a mobile-phone-based Breath CO meter prototype that attaches...