Several brightness illusions indicate that borders can dramatically affect the perception of adjoining surfaces. In the Craik–O’Brien–Cornsweet illusion, in particular, two equiluminant surfaces can appear different in brightness due to the contrast border between them. Although the psychophysical nature of this phenomenon has been well characterized, the neural circuitry underlying this effect...

accurate interpretation of radiographic images is dependent on viewing conditions. recently the number of radiology departments has been increased so it needs to use a workstation for reporting. the aim of this study was assess monitor performance and the effect of viewing conditions on object detection. this investigation aimed to quantify the effects of changes in box brightness and ambient l...

This paper considers the problem of estimating the brightness of visual stimuli. A number of physical asymmetries are seen to permit determination of brightness that is invariant to certain manipulations of the sensor responses, such as inversion. In particular, the light-dark range asymmetry is examined and is shown to result, over a certain range, in increased variability of sensor responses ...

The transformation of the RGB colour space to a hue, saturation and brightness colour space is essentially a conversion from a rectangular coordinate system to a cylindrical coordinate system. Nevertheless, a bewildering array of such conversions exist. We show that one of the main reasons for this is the dependence of the saturation values on the choice of the brightness function, and suggest ...

We demonstrate the unambiguous entangling operation of a photonic quantum-logic gate driven by an ultrabright solid-state single-photon source. Indistinguishable single photons emitted by a single semiconductor quantum dot in a micropillar optical cavity are used as target and control qubits. For a source brightness of 0.56 photons per pulse, the measured truth table has an overlap with the ide...

We masked White's and Benary's brightness illusions and simultaneous contrast with narrowband visual noise and measured detection thresholds and brightness. The noise was either isotropic or orientation filtered. A narrow spatial frequency tuning was found for detection and brightness for every stimulus. A narrow orientation tuning was also found: the strength of the illusions decreased (White ...

This paper has discuss the various techniques for image enhancement i.e histogram equalization, Brightness preserving bi-histogram equalization(BBHE), Dualistic Sub-Image Histogram Equalization (DSIHE), Minimum Mean Brightness Error Bi-HE Method (MMBEBHE), Recursive Mean –Separate HE Method (RMSHE),Mean brightness preserving histogram equalization(MBPHE).As well as it represents the comparison ...

We have measured the brightness of several helium free jet sources. Five converging nozzles with diameters between 0.6 and 5 m, and three tube nozzles with diameters between 2 and 10 m were studied at stagnation temperatures of 77 and 300 K and at stagnation pressures depending on nozzle size from 350 to 17000 kPa. Smaller nozzles produced higher brightness beams with values approaching 1028 s ...

We examined whether observers veridically perceive the reflectances of real objects under natural viewing conditions. A new forced-choice paradigm was used to measure observers' abilities to identify (not match) the reflectance of randomly crumpled gray papers across two levels of illumination, and also to simultaneously measure brightness discrimination thresholds for the same objects. Accurac...