From 081dcb377e30700145d037fde9f9395e4b91bc7d Mon Sep 17 00:00:00 2001 From: anthony Date: Fri, 10 Sep 2010 15:08:41 +0000 Subject: [PATCH] --- magick/resize.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) diff --git a/magick/resize.c b/magick/resize.c index 8dd469f82..f65b7f8f2 100644 --- a/magick/resize.c +++ b/magick/resize.c @@ -470,6 +470,9 @@ static MagickRealType Welsh(const MagickRealType x, % Blackman Hanning Hamming % Kaiser Lanczos (Sinc) % +% Polynomial Approximations (high precision fast versions) +% SincPolynomial +% % FIR filters are used as is, and are limited by that filters support window % (unless over-ridden). 'Gaussian' while classed as an IIR filter, is also % simply clipped by its support size (1.5). @@ -485,8 +488,8 @@ static MagickRealType Welsh(const MagickRealType x, % recommended as it removes the correct filter selection for different % filtering image operations. Selecting a window filtering method is better. % -% Lanczos is purely special case of a Sinc windowed Sinc, but defaulting to -% a 3 lobe support, rather that the default 4 lobe support. +% Lanczos is a special case of a Sinc windowed Sinc, but defaulting to +% a 3 lobe support, rather that the default 4 lobe support of the others. % % Special options can be used to override specific, or all the filter % settings. However doing so is not advisible unless you have expert @@ -516,25 +519,27 @@ static MagickRealType Welsh(const MagickRealType x, % used for simple filters like FIR filters, and the Gaussian Filter. % 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. % 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:win-support" Scale windowing function to this size instead. -% This causes the windowing (or self-windowing Lagrange filter) -% to act is if the support winodw 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. If unset this -% will equal the normal filter 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:verbose" Output verbose plotting data for graphing the -% resulting filter over the whole support range (with blur effect). +% "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). % % Set a true un-windowed Sinc filter with 10 lobes (very slow) % -set option:filter:filter Sinc @@ -555,9 +560,10 @@ static MagickRealType Welsh(const MagickRealType x, % o image: the image. % % o filter: the filter type, defining a preset filter, window and support. +% The artifact settings listed above will override those selections. % % o blur: blur the filter by this amount, use 1.0 if unknown. Image -% artifact "filter:blur" will override this old usage +% artifact "filter:blur" will override this internal usage. % % o radial: 1D orthogonal filter (Sinc) or 2D radial filter (Bessel) % -- 2.40.0