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Ensure that jagged pulses generated by "colour.volume.generate_pulse_…
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…waves" definition can be easily filtered.
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@KelSolaar
KelSolaar committed Feb 7, 2021
1 parent 2c27d42 commit 532a6f9
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Showing 2 changed files with 85 additions and 4 deletions.
72 changes: 68 additions & 4 deletions colour/volume/spectrum.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -52,7 +52,7 @@
_CACHE_OUTER_SURFACE_XYZ_POINTS = {}


def generate_pulse_waves(bins, pulse_order='Bins'):
def generate_pulse_waves(bins, pulse_order='Bins', filter_jagged_pulses=False):
"""
Generates the pulse waves of given number of bins necessary to totally
stimulate the colour matching functions and produce the *Rösch-MacAdam*
Expand Down Expand Up @@ -94,6 +94,23 @@ def generate_pulse_waves(bins, pulse_order='Bins'):
*Pulse Wave Width* ordering, instead of iterating over the pulse wave
widths first, iteration occurs over the bins, producing blocks of pulse
waves with increasing width.
filter_jagged_pulses : bool, optional
Whether to filter jagged pulses. When ``pulse_order`` is set to
*Pulse Wave Width*, the pulses are ordered by increasing width. Because
of the discrete nature of the underlying signal, the resulting pulses
will be jagged. For example assuming 5 bins, the center block with
the two extreme values added would be as follows::
0 0 0 0 0
0 0 1 0 0
0 0 1 1 0 <--
0 1 1 1 0
0 1 1 1 1 <--
1 1 1 1 1
Setting the ``filter_jagged_pulses`` parameter to `True` will result
in the removal of the two marked pulses above which avoid jagged lines
when plotting and having to resort to excessive ``bins`` values.
Returns
-------
Expand Down Expand Up @@ -130,6 +147,29 @@ def generate_pulse_waves(bins, pulse_order='Bins'):
[ 1., 1., 1., 0., 1.],
[ 1., 1., 1., 1., 1.]])
>>> generate_pulse_waves(5, 'Pulse Wave Width')
array([[ 0., 0., 0., 0., 0.],
[ 1., 0., 0., 0., 0.],
[ 1., 1., 0., 0., 0.],
[ 1., 1., 0., 0., 1.],
[ 1., 1., 1., 0., 1.],
[ 0., 1., 0., 0., 0.],
[ 0., 1., 1., 0., 0.],
[ 1., 1., 1., 0., 0.],
[ 1., 1., 1., 1., 0.],
[ 0., 0., 1., 0., 0.],
[ 0., 0., 1., 1., 0.],
[ 0., 1., 1., 1., 0.],
[ 0., 1., 1., 1., 1.],
[ 0., 0., 0., 1., 0.],
[ 0., 0., 0., 1., 1.],
[ 0., 0., 1., 1., 1.],
[ 1., 0., 1., 1., 1.],
[ 0., 0., 0., 0., 1.],
[ 1., 0., 0., 0., 1.],
[ 1., 0., 0., 1., 1.],
[ 1., 1., 0., 1., 1.],
[ 1., 1., 1., 1., 1.]])
>>> generate_pulse_waves(5, 'Pulse Wave Width', True)
array([[ 0., 0., 0., 0., 0.],
[ 1., 0., 0., 0., 0.],
[ 1., 1., 0., 0., 0.],
Expand Down Expand Up @@ -167,6 +207,9 @@ def generate_pulse_waves(bins, pulse_order='Bins'):
for j, square_wave_basis in enumerate(square_waves_basis):
square_waves.append(np.roll(square_wave_basis, i - j // 2))

if filter_jagged_pulses:
square_waves = square_waves[::2]

return np.vstack([
zeros(bins),
np.vstack(square_waves),
Expand All @@ -178,6 +221,7 @@ def XYZ_outer_surface(cmfs=MSDS_CMFS['CIE 1931 2 Degree Standard Observer']
.copy().align(SPECTRAL_SHAPE_OUTER_SURFACE_XYZ),
illuminant=sd_ones(SPECTRAL_SHAPE_OUTER_SURFACE_XYZ),
point_order='Bins',
filter_jagged_points=False,
**kwargs):
"""
Generates the *Rösch-MacAdam* colour solid, i.e. *CIE XYZ* colourspace
Expand All @@ -192,10 +236,28 @@ def XYZ_outer_surface(cmfs=MSDS_CMFS['CIE 1931 2 Degree Standard Observer']
Illuminant spectral distribution.
point_order : unicode, optional
**{'Bins', 'Pulse Wave Width'}**,
Method for ordering the pulse waves. *Bins* is the default order, with
Method for ordering the underlying pulse waves used to generate the
*Rösch-MacAdam* colour solid. *Bins* is the default order, with
*Pulse Wave Width* ordering, instead of iterating over the pulse wave
widths first, iteration occurs over the bins, producing blocks of pulse
waves with increasing width.
filter_jagged_points : bool, optional
Whether to filter the underlying jagged pulses. When ``point_order`` is
set to *Pulse Wave Width*, the pulses are ordered by increasing width.
Because of the discrete nature of the underlying signal, the resulting
pulses will be jagged. For example assuming 5 bins, the center block
with the two extreme values added would be as follows::
0 0 0 0 0
0 0 1 0 0
0 0 1 1 0 <--
0 1 1 1 0
0 1 1 1 1 <--
1 1 1 1 1
Setting the ``filter_jagged_points`` parameter to `True` will result
in the removal of the two marked pulses above which avoid jagged lines
when plotting and having to resort to excessive ``bins`` values.
Other Parameters
----------------
Expand Down Expand Up @@ -257,11 +319,13 @@ def XYZ_outer_surface(cmfs=MSDS_CMFS['CIE 1931 2 Degree Standard Observer']
settings = {'method': 'Integration', 'shape': cmfs.shape}
settings.update(kwargs)

key = (hash(cmfs), hash(illuminant), point_order, str(settings))
key = (hash(cmfs), hash(illuminant), point_order, filter_jagged_points,
str(settings))
XYZ = _CACHE_OUTER_SURFACE_XYZ.get(key)

if XYZ is None:
pulse_waves = generate_pulse_waves(len(cmfs.wavelengths), point_order)
pulse_waves = generate_pulse_waves(
len(cmfs.wavelengths), point_order, filter_jagged_points)
XYZ = msds_to_XYZ(pulse_waves, cmfs, illuminant, **settings) / 100

_CACHE_OUTER_SURFACE_XYZ[key] = XYZ
Expand Down
17 changes: 17 additions & 0 deletions colour/volume/tests/test_spectrum.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -96,6 +96,23 @@ def test_generate_pulse_waves(self):
np.sort(generate_pulse_waves(5), axis=0),
np.sort(generate_pulse_waves(5, 'Pulse Wave Width'), axis=0))

np.testing.assert_array_equal(
generate_pulse_waves(5, 'Pulse Wave Width', True),
np.array([
[0.0, 0.0, 0.0, 0.0, 0.0],
[1.0, 0.0, 0.0, 0.0, 0.0],
[1.0, 1.0, 0.0, 0.0, 1.0],
[0.0, 1.0, 0.0, 0.0, 0.0],
[1.0, 1.0, 1.0, 0.0, 0.0],
[0.0, 0.0, 1.0, 0.0, 0.0],
[0.0, 1.0, 1.0, 1.0, 0.0],
[0.0, 0.0, 0.0, 1.0, 0.0],
[0.0, 0.0, 1.0, 1.0, 1.0],
[0.0, 0.0, 0.0, 0.0, 1.0],
[1.0, 0.0, 0.0, 1.0, 1.0],
[1.0, 1.0, 1.0, 1.0, 1.0],
]))


class TestXYZOuterSurface(unittest.TestCase):
"""
Expand Down

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