Load the Munsell chip data and create images

Albert Munsell invented the Munsell color system. This system is widely used by artists and industry to describe colors.

The Munsell Corporation produced a set of surfaces that represent equally spaced samples in that color system. The data here represent 261 little surfaces (chips) in that space. The surfaces are at different hue, chroma and value levels.

The data include XYZ values and a specified illuminant ('C'). We plot the illuminant and an sRGB rendering of many of the Munsell chips

See also: munsell.mat, chromaticity, chromaticityPlot,

Copyright Imageval Consulting, LLC 2015

Contents

ieInit

Load the data from data/surfaces in iSET

load('munsell');

Here are the munsell XYZ values

mXYZ = munsell.XYZ;

% Reshape
mXYZ = reshape(mXYZ,261,9,3);

% Convert to srgb
srgb = xyz2srgb(mXYZ);

% Have a look
imagesc(srgb);

Plot the illuminant C, which is a kind of blue sky daylight

vcNewGraphWin;
plot(munsell.wavelength,munsell.illuminant);
grid on;

Here are the chromaticity coordinates of the surfaces

xy = chromaticity(munsell.XYZ);
chromaticityPlot(xy,'white')
ans = 

  Figure (3: ISET GraphWin) with properties:

      Number: 3
        Name: 'ISET GraphWin'
       Color: [1 1 1]
    Position: [0.0070 0.5500 0.2800 0.3600]
       Units: 'normalized'

  Use GET to show all properties

Here are the LAB coordinates of the surfaces

vcNewGraphWin;
plot3(munsell.LAB(:,2),munsell.LAB(:,3),munsell.LAB(:,1),'o')
grid on;
xlabel('a'); ylabel('b'); zlabel('L');

The data also have a representation in terms of hue and angle

% This is the famous Munsell notation
for idx = 1:45
    fprintf('Index %d: Munsell notation (hue value/chroma): %s %.1f/%.1f \n',idx,munsell.hue{idx},munsell.value(idx),munsell.angle(idx));
end
Index 1: Munsell notation (hue value/chroma): .00R 1.0/0.0 
Index 2: Munsell notation (hue value/chroma): .00R 1.0/0.0 
Index 3: Munsell notation (hue value/chroma): .00R 1.0/0.0 
Index 4: Munsell notation (hue value/chroma): .00R 1.0/0.0 
Index 5: Munsell notation (hue value/chroma): .00R 1.0/0.0 
Index 6: Munsell notation (hue value/chroma): .00R 1.0/0.0 
Index 7: Munsell notation (hue value/chroma): .00R 1.0/0.0 
Index 8: Munsell notation (hue value/chroma): 2.50R 1.0/2.5 
Index 9: Munsell notation (hue value/chroma): 2.50R 1.0/2.5 
Index 10: Munsell notation (hue value/chroma): 2.50R 1.0/2.5 
Index 11: Munsell notation (hue value/chroma): 2.50R 1.0/2.5 
Index 12: Munsell notation (hue value/chroma): 2.50R 1.0/2.5 
Index 13: Munsell notation (hue value/chroma): 5.00R 1.0/5.0 
Index 14: Munsell notation (hue value/chroma): 5.00R 1.0/5.0 
Index 15: Munsell notation (hue value/chroma): 5.00R 1.0/5.0 
Index 16: Munsell notation (hue value/chroma): 5.00R 1.0/5.0 
Index 17: Munsell notation (hue value/chroma): 5.00R 1.0/5.0 
Index 18: Munsell notation (hue value/chroma): 7.50R 1.0/7.5 
Index 19: Munsell notation (hue value/chroma): 7.50R 1.0/7.5 
Index 20: Munsell notation (hue value/chroma): 7.50R 1.0/7.5 
Index 21: Munsell notation (hue value/chroma): 7.50R 1.0/7.5 
Index 22: Munsell notation (hue value/chroma): 7.50R 1.0/7.5 
Index 23: Munsell notation (hue value/chroma): 10.00R 1.0/10.0 
Index 24: Munsell notation (hue value/chroma): 10.00R 1.0/10.0 
Index 25: Munsell notation (hue value/chroma): 10.00R 1.0/10.0 
Index 26: Munsell notation (hue value/chroma): 10.00R 1.0/10.0 
Index 27: Munsell notation (hue value/chroma): 10.00R 1.0/10.0 
Index 28: Munsell notation (hue value/chroma): 2.50YR 1.0/12.5 
Index 29: Munsell notation (hue value/chroma): 2.50YR 1.0/12.5 
Index 30: Munsell notation (hue value/chroma): 2.50YR 1.0/12.5 
Index 31: Munsell notation (hue value/chroma): 2.50YR 1.0/12.5 
Index 32: Munsell notation (hue value/chroma): 5.00YR 1.0/15.0 
Index 33: Munsell notation (hue value/chroma): 5.00YR 1.0/15.0 
Index 34: Munsell notation (hue value/chroma): 7.50YR 1.0/17.5 
Index 35: Munsell notation (hue value/chroma): 10.00YR 1.0/20.0 
Index 36: Munsell notation (hue value/chroma): 2.50Y 1.0/22.5 
Index 37: Munsell notation (hue value/chroma): 5.00Y 1.0/25.0 
Index 38: Munsell notation (hue value/chroma): 7.50Y 1.0/27.5 
Index 39: Munsell notation (hue value/chroma): 10.00Y 1.0/30.0 
Index 40: Munsell notation (hue value/chroma): 2.50GY 1.0/32.5 
Index 41: Munsell notation (hue value/chroma): 5.00GY 1.0/35.0 
Index 42: Munsell notation (hue value/chroma): 5.00GY 1.0/35.0 
Index 43: Munsell notation (hue value/chroma): 7.50GY 1.0/37.5 
Index 44: Munsell notation (hue value/chroma): 7.50GY 1.0/37.5 
Index 45: Munsell notation (hue value/chroma): 10.00GY 1.0/40.0