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Diffstat (limited to 'docs/filters.rst')
| -rw-r--r-- | docs/filters.rst | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/docs/filters.rst b/docs/filters.rst index 2906401..5227f3b 100644 --- a/docs/filters.rst +++ b/docs/filters.rst @@ -930,17 +930,27 @@ Stripe filtering Filter vertical stripes. The input and output are in 2D frequency domain. The filter multiplies horizontal frequencies (for frequency ky=0) with a - Gaussian profile centered at 0 frequency. + Gaussian profile centered at 0 frequency if ``vertical-sigma`` is 0. + Otherwise it applies also a vertical Gaussian profile (1 - Gaussian), which + enables filtering of not perfectly vertical stripes, which is useful for + broader stripes and stripes which are not perfectly straight. Example usage:: $ ufo-launch read path=sino.tif ! fft dimensions=2 ! filter-stripes sigma=1 ! ifft dimensions=2 ! write filename=sino-filtered.tif - .. gobj:prop:: sigma:float + .. gobj:prop:: horizontal-sigma:float + + Horizontal filter strength, which is the sigma of the Gaussian. Small + values, e.g. 1e-7 cause only the zero frequency to remain in the + signal, i.e. stronger filtering. Values around 1 are a good starting + point. + + .. gobj:prop:: vertical-sigma:float - Filter strength, which is the sigma of the gaussian. Small values, e.g. - 1e-7 cause only the zero frequency to remain in the signal, i.e. - stronger filtering. + Vertical filter strength, which is the sigma of the Gaussian. The larger + the value, the more non-vertical frequencies are removed. Value around 4 + is a good starting point. 1D stripe filtering |