% crossing is (36 sqrt 2 + 123)/(72 sqrt 2 + 47) which is almost
% identical to the first crossing of the other two.
%
-% 'EXPERT' OPTIONS
+% 'EXPERT' OPTIONS:
%
-% You can override any and all filter settings. This is not advised
-% unless you have expert knowledge of the use of resampling filtered
-% techniques. Check on the results of your selections using the
-% "filter:verbose" setting to make sure you get the exact filter you
-% want.
+% (Not recommended without expert knowledge of resampling and
+% filtering.)
+%
+% You can override any and all filter settings. Use "filter:verbose"
+% to make sure that the overall effect of your selections is as
+% expected.
+%
+% "filter:verbose" Output the exact results of the filter
+% selections made, as well as plotting data for graphing the
+% resulting filter over support range (blur adjusted).
%
% "filter:filter" Select the main function associated with
% this filter name, as the weighting function of the filter.
% This can be used to set a windowing function as a weighting
% function, for special purposes, such as graphing.
%
-% If a "filter:window" operation has not been provided, then a 'Box'
-% windowing function will be set to denote that no windowing function
-% is being used.
-%
-% "filter:window" Select this windowing function for the filter.
-% While any filter could be used as a windowing function, using the
-% 'first lobe' of that filter over the whole support window, using a
-% non-windowing function is not advisible. If no weighting filter
-% function is specifed a 'SincFast' filter will be used.
-%
-% "filter:lobes" Number of lobes to use for the Sinc/Jinc filter.
-% This a simpler method of setting filter support size that will
-% correctly handle the Sinc/Jinc switch for an operators filtering
-% requirements. Only integers should be given.
-%
-% "filter:support" Set the support size for filtering to the size given
-% This not recommended for Sinc/Jinc windowed filters (lobes should
-% be used instead). This will override any 'filter:lobes' option.
-%
-% "filter:win-support" Scale windowing function to this size instead.
-% This causes the windowing (or self-windowing Lagrange filter) to act
-% is if the support window it much much larger than what is actually
-% supplied to the calling operator. The filter however is still
-% clipped to the real support size given, by the support range suppiled
-% to the caller. If unset this will equal the normal filter support
+% If a "filter:window" operation has not been provided, then a
+% 'Box' windowing function will be set to denote that no
+% windowing function is being used.
+%
+% "filter:window" Select this windowing function for the filter.
+% While any filter could be used as a windowing function, using
+% the 'first lobe' of that filter over the whole support
+% window, using a non-windowing function is not advisible. If
+% no weighting filter function is specifed a 'SincFast' filter
+% will be used.
+%
+% "filter:lobes" Number of lobes to use for the Sinc/Jinc filter.
+% This a simpler method of setting filter support size that
+% will correctly handle the Sinc/Jinc switch for an operators
+% filtering requirements. Only integers should be given.
+%
+% "filter:support" Set the support size for filtering to the size
+% given This not recommended for Sinc/Jinc windowed filters
+% (lobes should be used instead). This will override any
+% 'filter:lobes' option.
+%
+% "filter:win-support" Scale windowing function to this size
+% instead. This causes the windowing (or self-windowing
+% Lagrange filter) to act is if the support window it much much
+% larger than what is actually supplied to the calling
+% operator. The filter however is still clipped to the real
+% support size given, by the support range suppiled to the
+% caller. If unset this will equal the normal filter support
% size.
%
-% "filter:blur" Scale the filter and support window by this amount.
+% "filter:blur" Scale the filter and support window by this amount.
% A value >1 will generally result in a more burred image with
% more ringing effects, while a value <1 will sharpen the
% resulting image with more aliasing and Morie effects.
%
-% "filter:sigma" The sigma value to use for the Gaussian filter only.
-% Defaults to '1/2' for orthogonal and 'sqrt(2)/2' for cylindrical
-% usage. It effectially provides a alturnative to 'blur' for Gaussians
-% without it also effecting the final 'practical support' size.
+% "filter:sigma" The sigma value to use for the Gaussian filter
+% only. Defaults to '1/2' for orthogonal and 'sqrt(2)/2' for
+% cylindrical usage. It effectially provides a alturnative to
+% 'blur' for Gaussians without it also effecting the final
+% 'practical support' size.
%
% "filter:b"
-% "filter:c" Override the preset B,C values for a Cubic type of filter
-% If only one of these are given it is assumes to be a 'Keys'
-% type of filter such that B+2C=1, where Keys 'alpha' value = C
+% "filter:c" Override the preset B,C values for a Cubic type of
+% filter If only one of these are given it is assumes to be a
+% 'Keys' type of filter such that B+2C=1, where Keys 'alpha'
+% value = C
%
-% "filter:verbose" Output the exact results of the filter selections
-% made, as well as plotting data for graphing the resulting filter
-% over support range (blur adjusted).
+% Examples:
%
% Set a true un-windowed Sinc filter with 10 lobes (very slow)
% -define filter:filter=Sinc
projects / imagemagick / commitdiff