From 43d70feb788318b124418c5c666f2120ee5ca930 Mon Sep 17 00:00:00 2001 From: Xuewei Meng Date: Mon, 10 May 2021 21:42:31 +0800 Subject: GSoC: Support fast guided filter. Two modes are supported in guided filter, basic mode and fast mode. Basic mode is the initial pushed guided filter without optimization. Fast mode is implemented based on the basic one by sub-sampling method. The sub-sampling ratio which can be defined by users controls the algorithm complexity. The larger the sub-sampling ratio, the lower the algorithm complexity. Signed-off-by: Xuewei Meng Reviewed-by: Steven Liu --- doc/filters.texi | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) (limited to 'doc') diff --git a/doc/filters.texi b/doc/filters.texi index 22d02c38f7..b574334bea 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -12963,12 +12963,22 @@ Apply guided filter for edge-preserving smoothing, dehazing and so on. The filter accepts the following options: @table @option @item radius -Set the radius in pixels. +Set the box radius in pixels. Allowed range is 1 to 20. Default is 3. @item eps -Set regularization parameter. -Allowed range is 0 to 1. Default is 0.1. +Set regularization parameter (with square). +Allowed range is 0 to 1. Default is 0.01. + +@item mode +Set filter mode. Can be @code{basic} or @code{fast}. +Default is @code{basic}. + +@item sub +Set subsampling ratio. +Allowed range is 1 to 64. +Default is always 1 for @code{basic} value of @var{mode} option, +and 4 for @code{fast} value of @var{mode} option. @item planes Set planes to filter. Default is first only. @@ -12987,8 +12997,8 @@ ffmpeg -i in.png -i in.png -filter_complex guided out.png @item Dehazing, structure-transferring filtering, detail enhancement with guided filter. -For the generation of guidance image, -see @url{http://kaiminghe.com/publications/pami12guidedfilter.pdf}. +For the generation of guidance image, refer to paper "Guided Image Filtering". +See: @url{http://kaiminghe.com/publications/pami12guidedfilter.pdf}. @example ffmpeg -i in.png -i guidance.png -filter_complex guided out.png @end example -- cgit v1.2.1