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added utilities for optimal distinguishable colors.

time-shift
Marco Ratto 2017-01-06 11:09:04 +01:00 committed by Stéphane Adjemian (Charybdis)
parent aa0eceeb38
commit a6f7e02d17
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46
license.txt
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@ -157,6 +157,52 @@ License: permissive
Unlimited permission is granted to everyone to use, copy, modify or
distribute this software.
Files: matlab/utilities\graphics\distinguishable_colors.m
Copyright 2010-2011 by Timothy E. Holy
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the distribution
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
Files: matlab/utilities\graphics\colorspace.m
Pascal Getreuer 2005-2010
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the distribution
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
Files: doc/dynare.texi doc/*.tex doc/*.svg doc/*.dia doc/*.pdf doc/*.bib
Copyright: 1996-2017 Dynare Team
License: GFDL-NIV-1.3+

1
matlab/dynare_config.m
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@ -68,6 +68,7 @@ p = {'/distributions/' ; ...
'/utilities/tests/src/' ; ...
'/utilities/dataset/' ; ...
'/utilities/general/' ; ...
'/utilities/graphics/' ; ...
'/modules/reporting/src/' ; ...
'/modules/reporting/macros/'};

515
matlab/utilities/graphics/colorspace.m Normal file
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@ -0,0 +1,515 @@
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
% All rights reserved.
%
% Redistribution and use in source and binary forms, with or without
% modification, are permitted provided that the following conditions are
% met:
%
% * Redistributions of source code must retain the above copyright
% notice, this list of conditions and the following disclaimer.
% * Redistributions in binary form must reproduce the above copyright
% notice, this list of conditions and the following disclaimer in
% the documentation and/or other materials provided with the distribution
%
% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
% AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
% IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
% ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
% LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
% SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
% CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
% POSSIBILITY OF SUCH DAMAGE.
%%% 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 601) Y'CbCr
% Wikipedia: http://en.wikipedia.org/wiki/YCbCr
% Poynton, Equation 3, scaling of R'G'B to Y'PbPr conversion
T = [65.481,128.553,24.966,16;-37.797,-74.203,112.0,128;112.0,-93.786,-18.214,128];
case 'jpegycbcr'
% Wikipedia: http://en.wikipedia.org/wiki/YCbCr
T = [0.299,0.587,0.114,0;-0.168736,-0.331264,0.5,0.5;0.5,-0.418688,-0.081312,0.5]*255;
case {'rgb','xyz','hsv','hsl','lab','luv','lch','cat02lms'}
T = Space;
otherwise
error(['Unknown color space, ''',Space,'''.']);
end
return;
function Image = rgb(Image,SrcSpace)
% Convert to sRGB from 'SrcSpace'
switch SrcSpace
case 'rgb'
return;
case 'hsv'
% Convert HSV to sRGB
Image = huetorgb((1 - Image(:,:,2)).*Image(:,:,3),Image(:,:,3),Image(:,:,1));
case 'hsl'
% Convert HSL to sRGB
L = Image(:,:,3);
Delta = Image(:,:,2).*min(L,1-L);
Image = huetorgb(L-Delta,L+Delta,Image(:,:,1));
case {'xyz','lab','luv','lch','cat02lms'}
% Convert to CIE XYZ
Image = xyz(Image,SrcSpace);
% Convert XYZ to RGB
T = [3.2406, -1.5372, -0.4986; -0.9689, 1.8758, 0.0415; 0.0557, -0.2040, 1.057];
R = T(1)*Image(:,:,1) + T(4)*Image(:,:,2) + T(7)*Image(:,:,3); % R
G = T(2)*Image(:,:,1) + T(5)*Image(:,:,2) + T(8)*Image(:,:,3); % G
B = T(3)*Image(:,:,1) + T(6)*Image(:,:,2) + T(9)*Image(:,:,3); % B
% Desaturate and rescale to constrain resulting RGB values to [0,1]
AddWhite = -min(min(min(R,G),B),0);
R = R + AddWhite;
G = G + AddWhite;
B = B + AddWhite;
% Apply gamma correction to convert linear RGB to sRGB
Image(:,:,1) = gammacorrection(R); % R'
Image(:,:,2) = gammacorrection(G); % G'
Image(:,:,3) = gammacorrection(B); % B'
otherwise % Conversion is through an affine transform
T = gettransform(SrcSpace);
temp = inv(T(:,1:3));
T = [temp,-temp*T(:,4)];
R = T(1)*Image(:,:,1) + T(4)*Image(:,:,2) + T(7)*Image(:,:,3) + T(10);
G = T(2)*Image(:,:,1) + T(5)*Image(:,:,2) + T(8)*Image(:,:,3) + T(11);
B = T(3)*Image(:,:,1) + T(6)*Image(:,:,2) + T(9)*Image(:,:,3) + T(12);
Image(:,:,1) = R;
Image(:,:,2) = G;
Image(:,:,3) = B;
end
% Clip to [0,1]
Image = min(max(Image,0),1);
return;
function Image = xyz(Image,SrcSpace)
% Convert to CIE XYZ from 'SrcSpace'
WhitePoint = [0.950456,1,1.088754];
switch SrcSpace
case 'xyz'
return;
case 'luv'
% Convert CIE L*uv to XYZ
WhitePointU = (4*WhitePoint(1))./(WhitePoint(1) + 15*WhitePoint(2) + 3*WhitePoint(3));
WhitePointV = (9*WhitePoint(2))./(WhitePoint(1) + 15*WhitePoint(2) + 3*WhitePoint(3));
L = Image(:,:,1);
Y = (L + 16)/116;
Y = invf(Y)*WhitePoint(2);
U = Image(:,:,2)./(13*L + 1e-6*(L==0)) + WhitePointU;
V = Image(:,:,3)./(13*L + 1e-6*(L==0)) + WhitePointV;
Image(:,:,1) = -(9*Y.*U)./((U-4).*V - U.*V); % X
Image(:,:,2) = Y; % Y
Image(:,:,3) = (9*Y - (15*V.*Y) - (V.*Image(:,:,1)))./(3*V); % Z
case {'lab','lch'}
Image = lab(Image,SrcSpace);
% Convert CIE L*ab to XYZ
fY = (Image(:,:,1) + 16)/116;
fX = fY + Image(:,:,2)/500;
fZ = fY - Image(:,:,3)/200;
Image(:,:,1) = WhitePoint(1)*invf(fX); % X
Image(:,:,2) = WhitePoint(2)*invf(fY); % Y
Image(:,:,3) = WhitePoint(3)*invf(fZ); % Z
case 'cat02lms'
% Convert CAT02 LMS to XYZ
T = inv([0.7328, 0.4296, -0.1624;-0.7036, 1.6975, 0.0061; 0.0030, 0.0136, 0.9834]);
L = Image(:,:,1);
M = Image(:,:,2);
S = Image(:,:,3);
Image(:,:,1) = T(1)*L + T(4)*M + T(7)*S; % X
Image(:,:,2) = T(2)*L + T(5)*M + T(8)*S; % Y
Image(:,:,3) = T(3)*L + T(6)*M + T(9)*S; % Z
otherwise % Convert from some gamma-corrected space
% Convert to sRGB
Image = rgb(Image,SrcSpace);
% Undo gamma correction
R = invgammacorrection(Image(:,:,1));
G = invgammacorrection(Image(:,:,2));
B = invgammacorrection(Image(:,:,3));
% Convert RGB to XYZ
T = inv([3.2406, -1.5372, -0.4986; -0.9689, 1.8758, 0.0415; 0.0557, -0.2040, 1.057]);
Image(:,:,1) = T(1)*R + T(4)*G + T(7)*B; % X
Image(:,:,2) = T(2)*R + T(5)*G + T(8)*B; % Y
Image(:,:,3) = T(3)*R + T(6)*G + T(9)*B; % Z
end
return;
function Image = hsv(Image,SrcSpace)
% Convert to HSV
Image = rgb(Image,SrcSpace);
V = max(Image,[],3);
S = (V - min(Image,[],3))./(V + (V == 0));
Image(:,:,1) = rgbtohue(Image);
Image(:,:,2) = S;
Image(:,:,3) = V;
return;
function Image = hsl(Image,SrcSpace)
% Convert to HSL
switch SrcSpace
case 'hsv'
% Convert HSV to HSL
MaxVal = Image(:,:,3);
MinVal = (1 - Image(:,:,2)).*MaxVal;
L = 0.5*(MaxVal + MinVal);
temp = min(L,1-L);
Image(:,:,2) = 0.5*(MaxVal - MinVal)./(temp + (temp == 0));
Image(:,:,3) = L;
otherwise
Image = rgb(Image,SrcSpace); % Convert to sRGB
% Convert sRGB to HSL
MinVal = min(Image,[],3);
MaxVal = max(Image,[],3);
L = 0.5*(MaxVal + MinVal);
temp = min(L,1-L);
S = 0.5*(MaxVal - MinVal)./(temp + (temp == 0));
Image(:,:,1) = rgbtohue(Image);
Image(:,:,2) = S;
Image(:,:,3) = L;
end
return;
function Image = lab(Image,SrcSpace)
% Convert to CIE L*a*b* (CIELAB)
WhitePoint = [0.950456,1,1.088754];
switch SrcSpace
case 'lab'
return;
case 'lch'
% Convert CIE L*CH to CIE L*ab
C = Image(:,:,2);
Image(:,:,2) = cos(Image(:,:,3)*pi/180).*C; % a*
Image(:,:,3) = sin(Image(:,:,3)*pi/180).*C; % b*
otherwise
Image = xyz(Image,SrcSpace); % Convert to XYZ
% Convert XYZ to CIE L*a*b*
X = Image(:,:,1)/WhitePoint(1);
Y = Image(:,:,2)/WhitePoint(2);
Z = Image(:,:,3)/WhitePoint(3);
fX = f(X);
fY = f(Y);
fZ = f(Z);
Image(:,:,1) = 116*fY - 16; % L*
Image(:,:,2) = 500*(fX - fY); % a*
Image(:,:,3) = 200*(fY - fZ); % b*
end
return;
function Image = luv(Image,SrcSpace)
% Convert to CIE L*u*v* (CIELUV)
WhitePoint = [0.950456,1,1.088754];
WhitePointU = (4*WhitePoint(1))./(WhitePoint(1) + 15*WhitePoint(2) + 3*WhitePoint(3));
WhitePointV = (9*WhitePoint(2))./(WhitePoint(1) + 15*WhitePoint(2) + 3*WhitePoint(3));
Image = xyz(Image,SrcSpace); % Convert to XYZ
Denom = Image(:,:,1) + 15*Image(:,:,2) + 3*Image(:,:,3);
U = (4*Image(:,:,1))./(Denom + (Denom == 0));
V = (9*Image(:,:,2))./(Denom + (Denom == 0));
Y = Image(:,:,2)/WhitePoint(2);
L = 116*f(Y) - 16;
Image(:,:,1) = L; % L*
Image(:,:,2) = 13*L.*(U - WhitePointU); % u*
Image(:,:,3) = 13*L.*(V - WhitePointV); % v*
return;
function Image = lch(Image,SrcSpace)
% Convert to CIE L*ch
Image = lab(Image,SrcSpace); % Convert to CIE L*ab
H = atan2(Image(:,:,3),Image(:,:,2));
H = H*180/pi + 360*(H < 0);
Image(:,:,2) = sqrt(Image(:,:,2).^2 + Image(:,:,3).^2); % C
Image(:,:,3) = H; % H
return;
function Image = cat02lms(Image,SrcSpace)
% Convert to CAT02 LMS
Image = xyz(Image,SrcSpace);
T = [0.7328, 0.4296, -0.1624;-0.7036, 1.6975, 0.0061; 0.0030, 0.0136, 0.9834];
X = Image(:,:,1);
Y = Image(:,:,2);
Z = Image(:,:,3);
Image(:,:,1) = T(1)*X + T(4)*Y + T(7)*Z; % L
Image(:,:,2) = T(2)*X + T(5)*Y + T(8)*Z; % M
Image(:,:,3) = T(3)*X + T(6)*Y + T(9)*Z; % S
return;
function Image = huetorgb(m0,m2,H)
% Convert HSV or HSL hue to RGB
N = size(H);
H = min(max(H(:),0),360)/60;
m0 = m0(:);
m2 = m2(:);
F = H - round(H/2)*2;
M = [m0, m0 + (m2-m0).*abs(F), m2];
Num = length(m0);
j = [2 1 0;1 2 0;0 2 1;0 1 2;1 0 2;2 0 1;2 1 0]*Num;
k = floor(H) + 1;
Image = reshape([M(j(k,1)+(1:Num).'),M(j(k,2)+(1:Num).'),M(j(k,3)+(1:Num).')],[N,3]);
return;
function H = rgbtohue(Image)
% Convert RGB to HSV or HSL hue
[M,i] = sort(Image,3);
i = i(:,:,3);
Delta = M(:,:,3) - M(:,:,1);
Delta = Delta + (Delta == 0);
R = Image(:,:,1);
G = Image(:,:,2);
B = Image(:,:,3);
H = zeros(size(R));
k = (i == 1);
H(k) = (G(k) - B(k))./Delta(k);
k = (i == 2);
H(k) = 2 + (B(k) - R(k))./Delta(k);
k = (i == 3);
H(k) = 4 + (R(k) - G(k))./Delta(k);
H = 60*H + 360*(H < 0);
H(Delta == 0) = nan;
return;
function Rp = gammacorrection(R)
Rp = zeros(size(R));
i = (R <= 0.0031306684425005883);
Rp(i) = 12.92*R(i);
Rp(~i) = real(1.055*R(~i).^0.416666666666666667 - 0.055);
return;
function R = invgammacorrection(Rp)
R = zeros(size(Rp));
i = (Rp <= 0.0404482362771076);
R(i) = Rp(i)/12.92;
R(~i) = real(((Rp(~i) + 0.055)/1.055).^2.4);
return;
function fY = f(Y)
fY = real(Y.^(1/3));
i = (Y < 0.008856);
fY(i) = Y(i)*(841/108) + (4/29);
return;
function Y = invf(fY)
Y = fY.^3;
i = (Y < 0.008856);
Y(i) = (fY(i) - 4/29)*(108/841);
return;

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function colors = distinguishable_colors(n_colors,bg,func)
% DISTINGUISHABLE_COLORS: pick colors that are maximally perceptually distinct
%
% When plotting a set of lines, you may want to distinguish them by color.
% By default, Matlab chooses a small set of colors and cycles among them,
% and so if you have more than a few lines there will be confusion about
% which line is which. To fix this problem, one would want to be able to
% pick a much larger set of distinct colors, where the number of colors
% equals or exceeds the number of lines you want to plot. Because our
% ability to distinguish among colors has limits, one should choose these
% colors to be "maximally perceptually distinguishable."
%
% This function generates a set of colors which are distinguishable
% by reference to the "Lab" color space, which more closely matches
% human color perception than RGB. Given an initial large list of possible
% colors, it iteratively chooses the entry in the list that is farthest (in
% Lab space) from all previously-chosen entries. While this "greedy"
% algorithm does not yield a global maximum, it is simple and efficient.
% Moreover, the sequence of colors is consistent no matter how many you
% request, which facilitates the users' ability to learn the color order
% and avoids major changes in the appearance of plots when adding or
% removing lines.
%
% Syntax:
% colors = distinguishable_colors(n_colors)
% Specify the number of colors you want as a scalar, n_colors. This will
% generate an n_colors-by-3 matrix, each row representing an RGB
% color triple. If you don't precisely know how many you will need in
% advance, there is no harm (other than execution time) in specifying
% slightly more than you think you will need.
%
% colors = distinguishable_colors(n_colors,bg)
% This syntax allows you to specify the background color, to make sure that
% your colors are also distinguishable from the background. Default value
% is white. bg may be specified as an RGB triple or as one of the standard
% "ColorSpec" strings. You can even specify multiple colors:
% bg = {'w','k'}
% or
% bg = [1 1 1; 0 0 0]
% will only produce colors that are distinguishable from both white and
% black.
%
% colors = distinguishable_colors(n_colors,bg,rgb2labfunc)
% By default, distinguishable_colors uses the image processing toolbox's
% color conversion functions makecform and applycform. Alternatively, you
% can supply your own color conversion function.
%
% Example:
% c = distinguishable_colors(25);
% figure
% image(reshape(c,[1 size(c)]))
%
% Example using the file exchange's 'colorspace':
% func = @(x) colorspace('RGB->Lab',x);
% c = distinguishable_colors(25,'w',func);
% Copyright 2010-2011 by Timothy E. Holy
% All rights reserved.
%
% Redistribution and use in source and binary forms, with or without
% modification, are permitted provided that the following conditions are
% met:
%
% * Redistributions of source code must retain the above copyright
% notice, this list of conditions and the following disclaimer.
% * Redistributions in binary form must reproduce the above copyright
% notice, this list of conditions and the following disclaimer in
% the documentation and/or other materials provided with the distribution
%
% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
% AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
% IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
% ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
% LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
% SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
% CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
% POSSIBILITY OF SUCH DAMAGE.
% Parse the inputs
if (nargin < 2)
bg = [1 1 1]; % default white background
else
if iscell(bg)
% User specified a list of colors as a cell aray
bgc = bg;
for i = 1:length(bgc)
bgc{i} = parsecolor(bgc{i});
end
bg = cat(1,bgc{:});
else
% User specified a numeric array of colors (n-by-3)
bg = parsecolor(bg);
end
end
% Generate a sizable number of RGB triples. This represents our space of
% possible choices. By starting in RGB space, we ensure that all of the
% colors can be generated by the monitor.
n_grid = 30; % number of grid divisions along each axis in RGB space
x = linspace(0,1,n_grid);
[R,G,B] = ndgrid(x,x,x);
rgb = [R(:) G(:) B(:)];
if (n_colors > size(rgb,1)/3)
error('You can''t readily distinguish that many colors');
end
% Convert to Lab color space, which more closely represents human
% perception
if (nargin > 2)
lab = func(rgb);
bglab = func(bg);
else
C = makecform('srgb2lab');
lab = applycform(rgb,C);
bglab = applycform(bg,C);
end
% If the user specified multiple background colors, compute distances
% from the candidate colors to the background colors
mindist2 = inf(size(rgb,1),1);
for i = 1:size(bglab,1)-1
dX = bsxfun(@minus,lab,bglab(i,:)); % displacement all colors from bg
dist2 = sum(dX.^2,2); % square distance
mindist2 = min(dist2,mindist2); % dist2 to closest previously-chosen color
end
% Iteratively pick the color that maximizes the distance to the nearest
% already-picked color
colors = zeros(n_colors,3);
lastlab = bglab(end,:); % initialize by making the "previous" color equal to background
for i = 1:n_colors
dX = bsxfun(@minus,lab,lastlab); % displacement of last from all colors on list
dist2 = sum(dX.^2,2); % square distance
mindist2 = min(dist2,mindist2); % dist2 to closest previously-chosen color
[~,index] = max(mindist2); % find the entry farthest from all previously-chosen colors
colors(i,:) = rgb(index,:); % save for output
lastlab = lab(index,:); % prepare for next iteration
end
end
function c = parsecolor(s)
if ischar(s)
c = colorstr2rgb(s);
elseif isnumeric(s) && size(s,2) == 3
c = s;
else
error('MATLAB:InvalidColorSpec','Color specification cannot be parsed.');
end
end
function c = colorstr2rgb(c)
% Convert a color string to an RGB value.
% This is cribbed from Matlab's whitebg function.
% Why don't they make this a stand-alone function?
rgbspec = [1 0 0;0 1 0;0 0 1;1 1 1;0 1 1;1 0 1;1 1 0;0 0 0];
cspec = 'rgbwcmyk';
k = find(cspec==c(1));
if isempty(k)
error('MATLAB:InvalidColorString','Unknown color string.');
end
if k~=3 || length(c)==1,
c = rgbspec(k,:);
elseif length(c)>2,
if strcmpi(c(1:3),'bla')
c = [0 0 0];
elseif strcmpi(c(1:3),'blu')
c = [0 0 1];
else
error('MATLAB:UnknownColorString', 'Unknown color string.');
end
end
end