filter2

Purpose

Two-dimensional digital filtering.

Synopsis

Y = filter2(B,X)
Y = filter2(B,X,'shape')

Description

Y = filter2(B,X) filters the data in X with the two-dimensional FIR filter in the matrix B. The result, Y, is computed using two-dimensional convolution and is the same size as X.

Y = filter2(B,X,'shape') returns Y computed via two-dimensional convolution with size specified by shape:

  • same returns the central part of the convolution that is the same size as X (default).
  • full returns the full two-dimensional convolution, size(Y) > size(X).
  • valid returns only those parts of the convolution that are computed without the zero-padded edges, size(Y) < size(X).

    Algorithm

    filter2 uses conv2 to compute the full two-dimensional convolution of the FIR filter with the input matrix. By default, filter2 extracts and returns the central part of the convolution that is the same size as the input matrix. Use the shape parameter to specify an alternate part of the convolution for return.

    See Also

    conv2, filter

    (c) Copyright 1994 by The MathWorks, Inc.