function?varargout?=?colorspace（Conversionvarargin）
%COLORSPACE??Convert?a?color?image?between?color?representations.
%???B?=?COLORSPACE（SA）?converts?the?color?representation?of?image?A
%???where?S?is?a?string?specifying?the?conversion.??S?tells?the
%???source?and?destination?color?spaces?S?=?‘dest<-src‘?or
%???alternatively?S?=?‘src->dest‘.??Supported?color?spaces?are
%
%?????‘RGB‘??????????????R‘G‘B‘?Red?Green?Blue?（ITU-R?BT.709?gamma-corrected）
%?????‘YPbPr‘????????????Luma?（ITU-R?BT.601）?+?Chroma?
%?????‘YCbCr‘/‘YCC‘??????Luma?+?Chroma?（“digitized“?version?of?Y‘PbPr）
%?????‘YUV‘??????????????NTSC?PAL?Y‘UV?Luma?+?Chroma
%?????‘YIQ‘??????????????NTSC?Y‘IQ?Luma?+?Chroma
%?????‘YDbDr‘????????????SECAM?Y‘DbDr?Luma?+?Chroma
%?????‘JPEGYCbCr‘????????JPEG-Y‘CbCr?Luma?+?Chroma
%?????‘HSV‘/‘HSB‘????????Hue?Saturation?Value/Brightness
%?????‘HSL‘/‘HLS‘/‘HSI‘??Hue?Saturation?Luminance/Intensity
%?????‘XYZ‘??????????????CIE?XYZ
%?????‘Lab‘??????????????CIE?L*a*b*?（CIELAB）
%?????‘Luv‘??????????????CIE?L*u*v*?（CIELUV）
%?????‘Lch‘??????????????CIE?L*ch?（CIELCH）
%
%??All?conversions?assume?2?degree?observer?and?D65?illuminant.??Color
%??space?names?are?case?insensitive.??When?R‘G‘B‘?is?the?source?or
%??destination?it?can?be?omitted.?For?example?‘yuv<-‘?is?short?for
%??‘yuv<-rgb‘.
%
%??MATLAB?uses?two?standard?data?formats?for?R‘G‘B‘:?double?data?with
%??intensities?in?the?range?0?to?1?and?uint8?data?with?integer-valued
%??intensities?from?0?to?255.??As?MATLAB‘s?native?datatype?double?data?is
%??the?natural?choice?and?the?R‘G‘B‘?format?used?by?colorspace.??However
%??for?memory?and?computational?performance?some?functions?also?operate
%??with?uint8?R‘G‘B‘.??Given?uint8?R‘G‘B‘?color?data?colorspace?will
%??first?cast?it?to?double?R‘G‘B‘?before?processing.
%
%??If?A?is?an?Mx3?array?like?a?colormap?B?will?also?have?size?Mx3.
%
%??[B1B2B3]?=?COLORSPACE（SA）?specifies?separate?output?channels.
%??COLORSPACE（SA1A2A3）?specifies?separate?input?channels.

%?Pascal?Getreuer?2005-2006

%%%?Input?parsing?%%%
if?nargin?[SrcSpaceDestSpace]?=?parse（Conversion）;

if?nargin?==?2
???Image?=?varargin{1};
elseif?nargin?>=?3
???Image?=?cat（3varargin{:}）;
else
???error（‘Invalid?number?of?input?arguments.‘）;
end

FlipDims?=?（size（Image3）?==?1）;

if?FlipDims?Image?=?permute（Image[132]）;?end
if?~isa（Image‘double‘）?Image?=?double（Image）/255;?end
if?size（Image3）?~=?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（::