11.1 Convolution functions
- boxcar(data, boxshape, output=None, mode='nearest', cval=0.0)
-
boxcar computes a 1D or 2D boxcar filter on every 1D or
2D subarray of data. boxshape is a tuple of integers
specifying the dimensions of the filter, e.g.
(3,3) If
output is specified, it should be the same shape as
data and the result will be stored in it. In that case
None will be returned.
Supported modes include:
- nearest:
- Elements beyond boundary come from nearest edge pixel.
- wrap:
- Elements beyond boundary come from the opposite array
edge.
- reflect:
- Elements beyond boundary come from reflection on same
array edge.
- constant:
- Elements beyond boundary are set to 'cval', an
optional numerical parameter; the default value is
0.0.
- convolve(data, kernel, mode=FULL)
-
Returns the discrete, linear convolution of 1-D sequences data and
kernel. mode can be VALID, SAME, or
FULL
to specify the size of the resulting sequence. See section
11.2.
- convolve2d(data, kernel, output=None, fft=0, mode='nearest', cval=0.0)
-
Return the 2-dimensional convolution of Data and kernel. If
output is not None, the result is stored in output and
None is returned. fft is used to switch between FFT based
convolution and the naiive algorithm, defaulting to naiive. fft mode
becomes beneficial as the size of the kernel grows; for small kernels, the
naiive algorithm is more efficient. modes are identical
to those of boxcar.
- correlate(data, kernel, mode=FULL)
-
Return the cross-correlation of data and kernel. mode can be
VALID, SAME, or
FULL to specify the size of the
resulting sequence. See section 11.2.
- correlate2d(data, kernel, output=None, fft=0, mode='nearest', cval=0.0)
-
Return the 2-dimensional correlation of Data and kernel. If
output is not None, the result is stored in output and
None is returned. fft is used to switch between FFT based
correlation and the naiive algorithm, defaulting to naiive. fft mode
becomes beneficial as the size of the kernel grows; for small kernels, the
naiive algorithm is more efficient. modes are identical to those of
boxcar.
Note:
cross_correlate is deprecated and should not be used.
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