Tomasz Urbanowicz
26-09-2006, 09:40
Witam
Mam prośbę o rzetelne przetłumaczenie opisu trzech parametrów USM:
Amount sets the intensity of the sharpening halo. At low settings, it takes more difference between levels for the sharpening haloes to reach pure white and solid black; at higher settings, it takes less difference.
Radius is the control that sets the width of the sharpening haloes, though it also has some effect on their intensity. However, since it was designed by engineers rather than photographers, the number you enter into the Radius field doesn't actually produce haloes of that size (not that it's possible to produce a sharpening halo 0.4 pixels wide).
What the Radius setting actually does is a little more complicated. The Unsharp Mask filter changes pixels one at a time, examining the surrounding pixels to determine the difference in contrast between the subject pixel and its neighbors. The Radius setting tells the filter how many surrounding pixels to take into account when calculating the new value for the subject pixel.
The net effect, however, is that low Radius settings produce narrow sharpening haloes and higher settings produce wider ones. (At very high settings, the sharpening haloes collide and merge into one another, so the effect changes from a pure sharpening to an overall contrast adjustmentsee "Midtone Contrast,")
Threshold delays the onset of the sharpening haloes by telling the Unsharp Mask filter to ignore a certain amount of difference between pixels before applying any sharpening.
Z góry dziękuję za pomoc.
Mam prośbę o rzetelne przetłumaczenie opisu trzech parametrów USM:
Amount sets the intensity of the sharpening halo. At low settings, it takes more difference between levels for the sharpening haloes to reach pure white and solid black; at higher settings, it takes less difference.
Radius is the control that sets the width of the sharpening haloes, though it also has some effect on their intensity. However, since it was designed by engineers rather than photographers, the number you enter into the Radius field doesn't actually produce haloes of that size (not that it's possible to produce a sharpening halo 0.4 pixels wide).
What the Radius setting actually does is a little more complicated. The Unsharp Mask filter changes pixels one at a time, examining the surrounding pixels to determine the difference in contrast between the subject pixel and its neighbors. The Radius setting tells the filter how many surrounding pixels to take into account when calculating the new value for the subject pixel.
The net effect, however, is that low Radius settings produce narrow sharpening haloes and higher settings produce wider ones. (At very high settings, the sharpening haloes collide and merge into one another, so the effect changes from a pure sharpening to an overall contrast adjustmentsee "Midtone Contrast,")
Threshold delays the onset of the sharpening haloes by telling the Unsharp Mask filter to ignore a certain amount of difference between pixels before applying any sharpening.
Z góry dziękuję za pomoc.