meanshift分割算法的matlab实现，完整标准代码+中文注释

function varargout = colorspace(Conversion,varargin) %COLORSPACE Transform a color image between color representations. % B = COLORSPACE(S,A) transforms the color representation of image A % where S is a string specifying the conversion. The input array A % should be a real full double array of size Mx3 or MxNx3. The output B % is the same size as A. % % S tells the source and destination color spaces, S = 'dest<-src', or % alternatively, S = 'src->dest'. Supported color spaces are % % 'RGB' sRGB IEC 61966-2-1 % 'YCbCr' Luma + Chroma ("digitized" version of Y'PbPr) % 'JPEG-YCbCr' Luma + Chroma space used in JFIF JPEG % 'YDbDr' SECAM Y'DbDr Luma + Chroma % 'YPbPr' Luma (ITU-R BT.601) + Chroma % 'YUV' NTSC PAL Y'UV Luma + Chroma % 'YIQ' NTSC Y'IQ Luma + Chroma % 'HSV' or 'HSB' Hue Saturation Value/Brightness % 'HSL' or 'HLS' Hue Saturation Luminance % 'HSI' Hue Saturation Intensity % 'XYZ' CIE 1931 XYZ % 'Lab' CIE 1976 L*a*b* (CIELAB) % 'Luv' CIE L*u*v* (CIELUV) % 'LCH' CIE L*C*H* (CIELCH) % 'CAT02 LMS' CIE CAT02 LMS % % All conversions assume 2 degree observer and D65 illuminant. % % Color space names are case insensitive and spaces are ignored. When % sRGB is the source or destination, it can be omitted. For example % 'yuv<-' is short for 'yuv<-rgb'. % % For sRGB, the values should be scaled between 0 and 1. Beware that % transformations generally do not constrain colors to be "in gamut." % Particularly, transforming from another space to sRGB may obtain % R'G'B' values outside of the [0,1] range. So the result should be % clamped to [0,1] before displaying: % image(min(max(B,0),1)); % Clamp B to [0,1] and display % % sRGB (Red Green Blue) is the (ITU-R BT.709 gamma-corrected) standard % red-green-blue representation of colors used in digital imaging. The % components should be scaled between 0 and 1. The space can be % visualized geometrically as a cube. % % Y'PbPr, Y'CbCr, Y'DbDr, Y'UV, and Y'IQ are related to sRGB by linear % transformations. These spaces separate a color into a grayscale % luminance component Y and two chroma components. The valid ranges of % the components depends on the space. % % HSV (Hue Saturation Value) is related to sRGB by % H = hexagonal hue angle (0 <= H < 360), % S = C/V (0 <= S <= 1), % V = max(R',G',B') (0 <= V <= 1), % where C = max(R',G',B') - min(R',G',B'). The hue angle H is computed on % a hexagon. The space is geometrically a hexagonal cone. % % HSL (Hue Saturation Lightness) is related to sRGB by % H = hexagonal hue angle (0 <= H < 360), % S = C/(1 - |2L-1|) (0 <= S <= 1), % L = (max(R',G',B') + min(R',G',B'))/2 (0 <= L <= 1), % where H and C are the same as in HSV. Geometrically, the space is a % double hexagonal cone. % % HSI (Hue Saturation Intensity) is related to sRGB by % H = polar hue angle (0 <= H < 360), % S = 1 - min(R',G',B')/I (0 <= S <= 1), % I = (R'+G'+B')/3 (0 <= I <= 1). % Unlike HSV and HSL, the hue angle H is computed on a circle rather than % a hexagon. % % CIE XYZ is related to sRGB by inverse gamma correction followed by a % linear transform. Other CIE color spaces are defined relative to XYZ. % % CIE L*a*b*, L*u*v*, and L*C*H* are nonlinear functions of XYZ. The L* % component is designed to match closely with human perception of % lightness. The other two components describe the chroma. % % CIE CAT02 LMS is the linear transformation of XYZ using the MCAT02 % chromatic adaptation matrix. The space is designed to model the % response of the three types of cones in the human eye, where L, M, S, % correspond respectively to red ("long"), green ("medium"), and blue % ("short"). % Pascal Getreuer 2005-2010 %%% Input parsing %%% if nargin < 2, error('Not enough input arguments.'); end [SrcSpace,DestSpace] = parse(Conversion); if nargin == 2 Image = varargin{1}; elseif nargin >= 3 Image = cat(3,varargin{:}); else error('Invalid number of input arguments.'); end FlipDims = (size(Image,3) == 1); if FlipDims, Image = permute(Image,[1,3,2]); end if ~isa(Image,'double'), Image = double(Image)/255; end if size(Image,3) ~= 3, error('Invalid input size.'); end SrcT = gettransform(SrcSpace); DestT = gettransform(DestSpace); if ~ischar(SrcT) && ~ischar(DestT) % Both source and destination transforms are affine, so they % can be composed into one affine operation T = [DestT(:,1:3)*SrcT(:,1:3),DestT(:,1:3)*SrcT(:,4)+DestT(:,4)]; Temp = zeros(size(Image)); Temp(:,:,1) = T(1)*Image(:,:,1) + T(4)*Image(:,:,2) + T(7)*Image(:,:,3) + T(10); Temp(:,:,2) = T(2)*Image(:,:,1) + T(5)*Image(:,:,2) + T(8)*Image(:,:,3) + T(11); Temp(:,:,3) = T(3)*Image(:,:,1) + T(6)*Image(:,:,2) + T(9)*Image(:,:,3) + T(12); Image = Temp; elseif ~ischar(DestT) Image = rgb(Image,SrcSpace); Temp = zeros(size(Image)); Temp(:,:,1) = DestT(1)*Image(:,:,1) + DestT(4)*Image(:,:,2) + DestT(7)*Image(:,:,3) + DestT(10); Temp(:,:,2) = DestT(2)*Image(:,:,1) + DestT(5)*Image(:,:,2) + DestT(8)*Image(:,:,3) + DestT(11); Temp(:,:,3) = DestT(3)*Image(:,:,1) + DestT(6)*Image(:,:,2) + DestT(9)*Image(:,:,3) + DestT(12); Image = Temp; else Image = feval(DestT,Image,SrcSpace); end %%% Output format %%% if nargout > 1 varargout = {Image(:,:,1),Image(:,:,2),Image(:,:,3)}; else if FlipDims, Image = permute(Image,[1,3,2]); end varargout = {Image}; end return; function [SrcSpace,DestSpace] = parse(Str) % Parse conversion argument if ischar(Str) Str = lower(strrep(strrep(Str,'-',''),'=','')); k = find(Str == '>'); if length(k) == 1 % Interpret the form 'src->dest' SrcSpace = Str(1:k-1); DestSpace = Str(k+1:end); else k = find(Str == '<'); if length(k) == 1 % Interpret the form 'dest<-src' DestSpace = Str(1:k-1); SrcSpace = Str(k+1:end); else error(['Invalid conversion, ''',Str,'''.']); end end SrcSpace = alias(SrcSpace); DestSpace = alias(DestSpace); else SrcSpace = 1; % No source pre-transform DestSpace = Conversion; if any(size(Conversion) ~= 3), error('Transformation matrix must be 3x3.'); end end return; function Space = alias(Space) Space = strrep(strrep(Space,'cie',''),' ',''); if isempty(Space) Space = 'rgb'; end switch Space case {'ycbcr','ycc'} Space = 'ycbcr'; case {'hsv','hsb'} Space = 'hsv'; case {'hsl','hsi','hls'} Space = 'hsl'; case {'rgb','yuv','yiq','ydbdr','ycbcr','jpegycbcr','xyz','lab','luv','lch'} return; end return; function T = gettransform(Space) % Get a colorspace transform: either a matrix describing an affine transform, % or a string referring to a conversion subroutine switch Space case 'ypbpr' T = [0.299,0.587,0.114,0;-0.1687367,-0.331264,0.5,0;0.5,-0.418688,-0.081312,0]; case 'yuv' % sRGB to NTSC/PAL YUV % Wikipedia: http://en.wikipedia.org/wiki/YUV T = [0.299,0.587,0.114,0;-0.147,-0.289,0.436,0;0.615,-0.515,-0.100,0]; case 'ydbdr' % sRGB to SECAM YDbDr % Wikipedia: http://en.wikipedia.org/wiki/YDbDr T = [0.299,0.587,0.114,0;-0.450,-0.883,1.333,0;-1.333,1.116,0.217,0]; case 'yiq' % sRGB in [0,1] to NTSC YIQ in [0,1];[-0.595716,0.595716];[-0.522591,0.522591]; % Wikipedia: http://en.wikipedia.org/wiki/YIQ T = [0.299,0.587,0.114,0;0.595716,-0.274453,-0.321263,0;0.211456,-0.522591,0.311135,0]; case 'ycbcr' % sRGB (range [0,1]) to ITU-R BRT.601 (CCIR