01-03-2013, 11:17 AM
Spatial Filtering
Spatial Filtering.ppt (Size: 4.93 MB / Downloads: 98)
The word “filtering” has been borrowed from the frequency domain.
Filters are classified as:
Low-pass (i.e., preserve low frequencies)
High-pass (i.e., preserve high frequencies)
Band-pass (i.e., preserve frequencies within a band)
Band-reject (i.e., reject frequencies within a band)
Linear Spatial Filtering Methods
Two main linear spatial filtering methods:
Correlation
Convolution
Filters
Smoothing (i.e., low-pass filters)
Reduce noise and small details.
The elements of the mask must be positive.
Sum of mask elements is 1
Sharpening (i.e., high-pass filters)
Highlight fine detail or enhance detail that has been blurred.
The elements of the mask contain both positive and negative weights.
Sum of the mask weights is 0