The greyvalues of digitized one- or two-dimensional signals are typically generated by an analogue-to-digital converter (ADC), by sampling a continuous signal at fixed intervals (e.g. in time), and quantizing (digitizing) the samples. The sampling (or point sampling) theorem states that a band-limited analogue signal , i.e. a signal in a finite frequency band (e.g. between 0 and BHz), can be completely reconstructed from its samples , if the sampling frequency is greater than (the Nyquist rate); expressed in the , this that the sampling interval is at most seconds. Undersampling can produce serious errors (aliasing) by introducing artifacts of low frequencies, both in one-dimensional signals and in digital .
Originally from the Data Analysis Briefbook (http://rkb.home.cern.ch/rkb/titleA.htmlhttp://rkb.home.cern.ch/rkb/titleA.html)
|Date of creation||2013-03-22 12:04:25|
|Last modified on||2013-03-22 12:04:25|
|Last modified by||akrowne (2)|