Created
September 16, 2020 10:53
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[Matlab] Viridis colormap. Simple, without any external toolbox dependencies.
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function map = viridis(N) | |
%% Viridis colormap | |
% Perceptually uniform colormap | |
% Based on matlab ports of the matplotlib colormaps. | |
if nargin<1 || isempty(N), N = size(get(gcf,'colormap'),1); end | |
raw = [0.267004,0.004874,0.329415; 0.268510,0.009605,0.335427; 0.269944,0.014625,0.341379; 0.271305,0.019942,0.347269; 0.272594,0.025563,0.353093; 0.273809,0.031497,0.358853; 0.274952,0.037752,0.364543; 0.276022,0.044167,0.370164; 0.277018,0.050344,0.375715; 0.277941,0.056324,0.381191; 0.278791,0.062145,0.386592; 0.279566,0.067836,0.391917; 0.280267,0.073417,0.397163; 0.280894,0.078907,0.402329; 0.281446,0.084320,0.407414; 0.281924,0.089666,0.412415; 0.282327,0.094955,0.417331; 0.282656,0.100196,0.422160; 0.282910,0.105393,0.426902; 0.283091,0.110553,0.431554; 0.283197,0.115680,0.436115; 0.283229,0.120777,0.440584; 0.283187,0.125848,0.444960; 0.283072,0.130895,0.449241; 0.282884,0.135920,0.453427; 0.282623,0.140926,0.457517; 0.282290,0.145912,0.461510; 0.281887,0.150881,0.465405; 0.281412,0.155834,0.469201; 0.280868,0.160771,0.472899; 0.280255,0.165693,0.476498; 0.279574,0.170599,0.479997; 0.278826,0.175490,0.483397; 0.278012,0.180367,0.486697; 0.277134,0.185228,0.489898; 0.276194,0.190074,0.493001; 0.275191,0.194905,0.496005; 0.274128,0.199721,0.498911; 0.273006,0.204520,0.501721; 0.271828,0.209303,0.504434; 0.270595,0.214069,0.507052; 0.269308,0.218818,0.509577; 0.267968,0.223549,0.512008; 0.266580,0.228262,0.514349; 0.265145,0.232956,0.516599; 0.263663,0.237631,0.518762; 0.262138,0.242286,0.520837; 0.260571,0.246922,0.522828; 0.258965,0.251537,0.524736; 0.257322,0.256130,0.526563; 0.255645,0.260703,0.528312; 0.253935,0.265254,0.529983; 0.252194,0.269783,0.531579; 0.250425,0.274290,0.533103; 0.248629,0.278775,0.534556; 0.246811,0.283237,0.535941; 0.244972,0.287675,0.537260; 0.243113,0.292092,0.538516; 0.241237,0.296485,0.539709; 0.239346,0.300855,0.540844; 0.237441,0.305202,0.541921; 0.235526,0.309527,0.542944; 0.233603,0.313828,0.543914; 0.231674,0.318106,0.544834; 0.229739,0.322361,0.545706; 0.227802,0.326594,0.546532; 0.225863,0.330805,0.547314; 0.223925,0.334994,0.548053; 0.221989,0.339161,0.548752; 0.220057,0.343307,0.549413; 0.218130,0.347432,0.550038; 0.216210,0.351535,0.550627; 0.214298,0.355619,0.551184; 0.212395,0.359683,0.551710; 0.210503,0.363727,0.552206; 0.208623,0.367752,0.552675; 0.206756,0.371758,0.553117; 0.204903,0.375746,0.553533; 0.203063,0.379716,0.553925; 0.201239,0.383670,0.554294; 0.199430,0.387607,0.554642; 0.197636,0.391528,0.554969; 0.195860,0.395433,0.555276; 0.194100,0.399323,0.555565; 0.192357,0.403199,0.555836; 0.190631,0.407061,0.556089; 0.188923,0.410910,0.556326; 0.187231,0.414746,0.556547; 0.185556,0.418570,0.556753; 0.183898,0.422383,0.556944; 0.182256,0.426184,0.557120; 0.180629,0.429975,0.557282; 0.179019,0.433756,0.557430; 0.177423,0.437527,0.557565; 0.175841,0.441290,0.557685; 0.174274,0.445044,0.557792; 0.172719,0.448791,0.557885; 0.171176,0.452530,0.557965; 0.169646,0.456262,0.558030; 0.168126,0.459988,0.558082; 0.166617,0.463708,0.558119; 0.165117,0.467423,0.558141; 0.163625,0.471133,0.558148; 0.162142,0.474838,0.558140; 0.160665,0.478540,0.558115; 0.159194,0.482237,0.558073; 0.157729,0.485932,0.558013; 0.156270,0.489624,0.557936; 0.154815,0.493313,0.557840; 0.153364,0.497000,0.557724; 0.151918,0.500685,0.557587; 0.150476,0.504369,0.557430; 0.149039,0.508051,0.557250; 0.147607,0.511733,0.557049; 0.146180,0.515413,0.556823; 0.144759,0.519093,0.556572; 0.143343,0.522773,0.556295; 0.141935,0.526453,0.555991; 0.140536,0.530132,0.555659; 0.139147,0.533812,0.555298; 0.137770,0.537492,0.554906; 0.136408,0.541173,0.554483; 0.135066,0.544853,0.554029; 0.133743,0.548535,0.553541; 0.132444,0.552216,0.553018; 0.131172,0.555899,0.552459; 0.129933,0.559582,0.551864; 0.128729,0.563265,0.551229; 0.127568,0.566949,0.550556; 0.126453,0.570633,0.549841; 0.125394,0.574318,0.549086; 0.124395,0.578002,0.548287; 0.123463,0.581687,0.547445; 0.122606,0.585371,0.546557; 0.121831,0.589055,0.545623; 0.121148,0.592739,0.544641; 0.120565,0.596422,0.543611; 0.120092,0.600104,0.542530; 0.119738,0.603785,0.541400; 0.119512,0.607464,0.540218; 0.119423,0.611141,0.538982; 0.119483,0.614817,0.537692; 0.119699,0.618490,0.536347; 0.120081,0.622161,0.534946; 0.120638,0.625828,0.533488; 0.121380,0.629492,0.531973; 0.122312,0.633153,0.530398; 0.123444,0.636809,0.528763; 0.124780,0.640461,0.527068; 0.126326,0.644107,0.525311; 0.128087,0.647749,0.523491; 0.130067,0.651384,0.521608; 0.132268,0.655014,0.519661; 0.134692,0.658636,0.517649; 0.137339,0.662252,0.515571; 0.140210,0.665859,0.513427; 0.143303,0.669459,0.511215; 0.146616,0.673050,0.508936; 0.150148,0.676631,0.506589; 0.153894,0.680203,0.504172; 0.157851,0.683765,0.501686; 0.162016,0.687316,0.499129; 0.166383,0.690856,0.496502; 0.170948,0.694384,0.493803; 0.175707,0.697900,0.491033; 0.180653,0.701402,0.488189; 0.185783,0.704891,0.485273; 0.191090,0.708366,0.482284; 0.196571,0.711827,0.479221; 0.202219,0.715272,0.476084; 0.208030,0.718701,0.472873; 0.214000,0.722114,0.469588; 0.220124,0.725509,0.466226; 0.226397,0.728888,0.462789; 0.232815,0.732247,0.459277; 0.239374,0.735588,0.455688; 0.246070,0.738910,0.452024; 0.252899,0.742211,0.448284; 0.259857,0.745492,0.444467; 0.266941,0.748751,0.440573; 0.274149,0.751988,0.436601; 0.281477,0.755203,0.432552; 0.288921,0.758394,0.428426; 0.296479,0.761561,0.424223; 0.304148,0.764704,0.419943; 0.311925,0.767822,0.415586; 0.319809,0.770914,0.411152; 0.327796,0.773980,0.406640; 0.335885,0.777018,0.402049; 0.344074,0.780029,0.397381; 0.352360,0.783011,0.392636; 0.360741,0.785964,0.387814; 0.369214,0.788888,0.382914; 0.377779,0.791781,0.377939; 0.386433,0.794644,0.372886; 0.395174,0.797475,0.367757; 0.404001,0.800275,0.362552; 0.412913,0.803041,0.357269; 0.421908,0.805774,0.351910; 0.430983,0.808473,0.346476; 0.440137,0.811138,0.340967; 0.449368,0.813768,0.335384; 0.458674,0.816363,0.329727; 0.468053,0.818921,0.323998; 0.477504,0.821444,0.318195; 0.487026,0.823929,0.312321; 0.496615,0.826376,0.306377; 0.506271,0.828786,0.300362; 0.515992,0.831158,0.294279; 0.525776,0.833491,0.288127; 0.535621,0.835785,0.281908; 0.545524,0.838039,0.275626; 0.555484,0.840254,0.269281; 0.565498,0.842430,0.262877; 0.575563,0.844566,0.256415; 0.585678,0.846661,0.249897; 0.595839,0.848717,0.243329; 0.606045,0.850733,0.236712; 0.616293,0.852709,0.230052; 0.626579,0.854645,0.223353; 0.636902,0.856542,0.216620; 0.647257,0.858400,0.209861; 0.657642,0.860219,0.203082; 0.668054,0.861999,0.196293; 0.678489,0.863742,0.189503; 0.688944,0.865448,0.182725; 0.699415,0.867117,0.175971; 0.709898,0.868751,0.169257; 0.720391,0.870350,0.162603; 0.730889,0.871916,0.156029; 0.741388,0.873449,0.149561; 0.751884,0.874951,0.143228; 0.762373,0.876424,0.137064; 0.772852,0.877868,0.131109; 0.783315,0.879285,0.125405; 0.793760,0.880678,0.120005; 0.804182,0.882046,0.114965; 0.814576,0.883393,0.110347; 0.824940,0.884720,0.106217; 0.835270,0.886029,0.102646; 0.845561,0.887322,0.099702; 0.855810,0.888601,0.097452; 0.866013,0.889868,0.095953; 0.876168,0.891125,0.095250; 0.886271,0.892374,0.095374; 0.896320,0.893616,0.096335; 0.906311,0.894855,0.098125; 0.916242,0.896091,0.100717; 0.926106,0.897330,0.104071; 0.935904,0.898570,0.108131; 0.945636,0.899815,0.112838; 0.955300,0.901065,0.118128; 0.964894,0.902323,0.123941; 0.974417,0.903590,0.130215; 0.983868,0.904867,0.136897; 0.993248,0.906157,0.143936]; | |
map = raw2icmap(raw,N); | |
end | |
function map = raw2icmap(raw,N) | |
%% map = raw2icmap(raw,N) | |
% Interpolate raw colormap data to a colormap | |
raw = rgb2ycbcr(raw); % Convert to YCbCr colorspace | |
t = linspace(0,1,size(raw,1)); % Raw data axis | |
ti = linspace(0,1,N); % Interpolated axis | |
map = [... | |
interp1(t,raw(:,1),ti,'spline','extrap'); | |
interp1(t,raw(:,2),ti,'spline','extrap'); | |
interp1(t,raw(:,3),ti,'spline','extrap')]'; | |
map = ycbcr2rgb(map); % Convert back to RGB | |
map = max(0,min(1,map)); % Clamp between 0 and 1 | |
end | |
function ycbcr = rgb2ycbcr(rgb) | |
%% ycbcr = rgb2ycbcr(rgb) | |
% Conver [0 1] float Nx3 rgb colormap to corresponding YCbCr colorspace | |
% ITU-R BT.601 conversion standard | |
T = [... | |
0.256788235294118 -0.148223529411765 0.439215686274510 | |
0.504129411764706 -0.290992156862745 -0.367788235294118 | |
0.097905882352941 0.439215686274510 -0.071427450980392]; | |
offset = [0.062745098039216 0.501960784313725 0.501960784313725]; % [16 128 128]/255; | |
ycbcr = rgb*T + offset; | |
end | |
function rgb = ycbcr2rgb(ycbcr) | |
%% ycbcr = rgb2ycbcr(rgb) | |
% Conver [0 1] float Nx3 YCbCr colormap to corresponding RGB colorspace | |
% ITU-R BT.601 conversion standard | |
invT = [... | |
1.164383561643836 1.164383561643836 1.164383561643836 | |
0.000000301124397 -0.391762539941450 2.017232639556459 | |
1.596026887335704 -0.812968292162205 0.000003054261745]; | |
offset = [0.062745098039216 0.501960784313725 0.501960784313725]; % [16 128 128]/255; | |
rgb = (ycbcr - offset)*invT; | |
end |
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