Filter (normally low pass) that band limits an input signal before sampling to prevent aliasing noise.
A filter (normally low pass) which band limits the input signal before sampling, to less than half the sampling rate, to prevent aliasing noise.
A device that attenuates signal content outside the desired bandwidth. It precedes the analog-to-digital converter (ADC) in instrumentation designs theoretically allowing only frequencies in the pass-band to be sampled by the ADC. See also aliasing.
a low-pass filter that accomplishes this
a low-pass/high-cut filter that is set to cut of frequencies above the Nyquist Frequency
An analog filter that is used prior to sampling to limit the signal bandwidth to less than half the sample rate (generally low pass) to prevent aliasing distortion.
Most commonly a low-pass filter designed to filter out frequencies higher than 1/2 the sample rate in order to minimize aliasing.
Most digital cameras contain anti-aliasing filters positioned directly in front of the image sensor. These filters lower high-contrast areas of the picture very slightly so that such areas don’t go beyond the sampling ability of the image sensor. The result is a slightly softer image but one in which aliasing artefacts are reduced. As noted, the anti-aliasing filter also softens the image, so many professional cameras have removable anti-aliasing filters. The filters are rarely removable on consumer cameras, however.
An anti-aliasing filter is a filter used before a signal sampler, to restrict the bandwidth of a signal to approximately satisfy the Shannon-Nyquist-Kotelnikov sampling theorem. Since the theorem states that unambiguous interpretation of the signal from its samples is possible only when the power of frequencies outside the Nyquist bandwidth is zero, the anti-aliasing filter would have to have perfect stop-band rejection to completely satisfy the theorem. Every realizable anti-aliasing filter will permit some aliasing to occur; the amount of aliasing that does occur depends on how good the filter is.