"A 30% difference in brightness can easily be masked by clouds or the competing glare of urban lights," NASA officials wrote in a blog post.
Through these procedures we identified five defective arrays with sequential production numbers, for which one corner of the array showed a nonuniform overall difference in brightness that affected the readings in that region of the chip.
The method first computes pixel saliency in the two images (IR and visible) at multiple scales, then a merging process, based on a measure of the difference in brightness across the images, produces the final foreground mask.
Simply put, contrast ratio is a measure of the difference in brightness between the highest level of white and the deepest shade of black that a TV screen can produce.
"So far, our results suggest that we rely upon melanopsin to perceive the difference in brightness between a foggy day in London and bright summer sunshine in Manchester – we need to know whether it also provides the spatial information we rely upon for more complex sorts of vision," said Lucas.
DOI: http://dx.doi.org/10.7554/eLife.00031.002 Visual contrast is usually referred to as the difference in brightness between an object and the background (Hofstetter et al., 2000).
The image resulting from one field is segmented and the threshold is applied locally to overcome difference in brightness within an image (Additional file 1b, line 12-14 in FINDSPOT\3D Measurements).
Due to constant illumination, normalization is expected to eliminate the difference in brightness and allow a content-only comparison.
Accordingly, when plotted as a function of the average irradiance across the two eyes, steady-state firing was well described by a single sigmoid curve regardless of the interocular difference in brightness (F test, p = 0.27; Figure 3F).
It is noted here that the difference in brightness of the FESEM images represents the different thicknesses of the deposited ZnO structures.
